B Scientific Sessions (SS) Friday ....................... 139 Saturday................... 197 Sunday ..................... 243 Monday .................... 271 Tuesday.................... 303 S137 Scientific Sessions S138 A B C D E F G F H Scientific Sessions A B C D E F G H S139 Friday Friday, March 6 Scientific Sessions room A 2nd level room B 2nd level room C 2nd level room E1 entr. level room E2 entr. level room F1 entr. level room F2 entr. level room G/H lower level room I lower level room K lower level 07:00 07:00 07:30 07:30 08:00 08:00 08:30 CC 117 Cardiac Imaging Radiological anatomy and normal variants revisited (p. 8) 09:00 09:30 CC 116 Spinal Imaging and Intervention 6SLQDOEDVLFV Classics and news (p. 8) SF 1a Special Focus Session Assessment of tumor response (p. 9) EВі 120a Foundation Course: Imaging of the Urinary Tract ([DPLQDWLRQ WHFKQLTXHV (p. 10) EВі 120b Interactive Teaching Session Imaging in common clinical SUREOHPV6RIW tissue tumors (p. 10) 08:30 SF 1b Special Focus Session Prostate cancer (p. 11) RC 111 Neuro Basic MRI (p. 11) RC 115 Vascular Aortic imaging strategies (p. 12) RC 105 Computer Applications :KDWFDQ PACS do today? (p. 13) 10:00 10:30 SS 210 Musculoskeletal Tumors and ERQHPDUURZ (p. 142) 11:00 11:30 SS 201a GI Tract Gastrointestinal cancer: Detection and treatment response (p. 144) SS 206 Contrast Media New perspectives in contrastHQKDQFHG imaging (p. 146) EВі 220 SS 207 Foundation Genitourinary Course: Uterus and Imaging of ovaries: the Urinary MDCT and Tract MR studies Getting started (p. 148) (p. 17) SS 202 Breast New developments on digital systems LQEUHDVW diagnosis (p. 150) SS 208 Head and Neck 1HUYHVWHHWK eyes and ears (p. 153) SS 215 Vascular Vessel wall, SODTXH imaging and MRA (p. 155) SS 205 Computer Applications CAD, image registration and segmentation (p. 157) 12:00 11:00 11:30 12:00 Opening Ceremony/ Presentation of Honorary Members and Gold Medal Awards 12:30 12:30 Opening Lecture 13:00 13:00 (p. 18) 13:30 13:30 14:00 SS 301a Abdominal Viscera Liver: MR diffusion and spectroscopy (p. 169) 14:30 15:00 SS 310 Musculoskeletal $UWKULWLV (p. 171) SS 301b GI Tract CT FRORQRJUDSK\ (p. 173) SY 1 Bayer Schering Pharma Satellite Symposium (p. 522) EВі 320 Foundation Course: Imaging of the Urinary Tract Vascular and LQГЂDPPDWRU\ disease (p. 18) 14:00 SS 307 Genitourinary SS 302 Kidney: Breast 0RUSKRORJLFDO Screening and and functional diagnosis studies (p. 177) (p. 175) SS 308 Head and Neck New WHFKQLTXHV in tumor management (p. 179) SS 315 Vascular Magnetic resonance DQJLRJUDSK\ (p. 181) SS 305 Computer Applications New trends in PACS and workstations (p. 184) 15:30 14:30 15:00 15:30 16:00 CC 416 Spinal Imaging and Intervention 1HZLQVLJKWV in old SUREOHPV (p. 18) 16:30 18:00 registration (326ВЊVFLHQWLВїFH[KLELWLRQ 17:30 WHFKQLFDOH[KLELWLRQ 17:00 SF 4a Special Focus Session Dual energy computed WRPRJUDSK\ (p. 19) CC 418 Breast: From Basics to Advanced Imaging From SDWKRORJ\WR EUHDVWLPDJLQJ (p. 20) EВі 420a Foundation Course: Imaging of the Urinary Tract Renal masses (p. 21) EВі 420b Interactive Teaching Sessions Prostate cancer: Diagnosis, staging and follow-up (p. 21) RC 402 Breast &KDQJLQJ DSSURDFKHV WREUHDVW diseases? (p. 21) SF 4b Special Focus Session Neurodegenerative movement disorders: Practical guide (p. 22) 16:00 RC 415 Vascular Occlusive disease of WKHYLVFHUDO arteries (p. 23) RC 405 Computer Applications PACS in evolution (p. 24) 16:30 17:00 17:30 18:00 18:30 19:00 S140 09:30 10:00 10:30 18:30 09:00 19:00 A B C D E F G F H Scientific Sessions room L/M 1st level room N/O 1st level room P 1st level room Q 2nd level room R 1st level room U 2nd level room W 2nd level room X 1st level room Y 2nd level room Z 2nd level 07:00 07:30 07:30 08:00 08:00 08:30 09:00 09:30 08:30 MC 125 Extremity Joint MRI Upper H[WUHPLW\ Anatomy, variants and pitfalls (p. 14) MC 119 Advances in CT and MRI in Major Trauma Head and neck trauma (p. 14) RC 104 Chest %URQFKRJHQLF carcinoma (p. 15) RC 101 Abdominal and RC 108 Gastrointestinal Head and Neck (VRSKDJHDO 6NXOOEDVH cancer: Modern (p. 16) imaging (p. 16) 09:00 09:30 10:00 10:00 10:30 11:00 11:30 10:30 SS 211 Neuro Diffusion tensor imaging (p. 159) SS 201b Abdominal Viscera Liver: Hepatocellular carcinoma (p. 161) SS 204 Chest Pulmonary nodule detection and evaluation (p. 163) SS 209 Interventional Radiology 8SSHUERG\ interventions (p. 165) SS 203 Cardiac Coronary CT DQJLRJUDSK\ Reconstruction DOJRULWKPVDQG dose reduction (p. 167) WS 223 Cardiac CT PostProcessing and Analysis Hands-on :RUNVKRS Lecture WS 222 Experience Vascular Procedures Using Simulators 11:00 11:30 12:00 12:00 12:30 12:30 13:00 13:00 13:30 13:30 14:00 14:00 14:30 15:00 SS 311 Neuro Functional magnetic resonance imaging (p. 186) SS 306 Molecular Imaging Preclinical applications (p. 188) SS 304 Chest Pulmonary HPEROLVPDQG K\SHUWHQVLRQ (p. 190) SS 309 SS 303 Interventional Cardiac Radiology Musculoskeletal &DUGLRP\RSDWKLHV (p. 194) interventions (p. 192) WS 322 Experience Vascular Procedures Using Simulators ELGA (Electronic health record) (p. 136) WS 323 Cardiac CT PostProcessing and Analysis 15:00 15:30 15:30 16:00 16:00 16:30 17:00 14:30 MC 425 Extremity Joint MRI Lower H[WUHPLW\ Anatomy, variants and pitfalls (p. 25) RC 408 Head and Neck 6XSUDK\RLG neck (p. 25) RC 403 Cardiac Tips and tricks to improve your LPDJHTXDOLW\ (p. 26) RC 409 Interventional Radiology 7KHWUDXPD patient (p. 27) RC 401 Abdominal and Gastrointestinal &URKQВ¶VGLVHDVH (p. 27) 16:30 17:00 17:30 17:30 18:00 18:00 18:30 18:30 19:00 19:00 A B C D E F G H S141 Friday 07:00 Scientific Sessions 10:30 - 12:00 Room B SS 210 Tumors and bone marrow Moderators: K. Bohndorf; Augsburg/DE P.R. Kornaat; Leiden/NL 10:30 The value of proton magnetic resonance spectroscopy and diffusionweighted imaging in the differential diagnosis of musculoskeletal tumors X. Lin, J. Xue, J. Cao; Jinan/CN ([email protected]) Purpose: The apparent diffusion coefficient (ADC) and the content of lipid (Lip), choline (Cho) and creatine (Cr) of musculoskeletal tumors vary in different pathologic lesions. This study was carried out to evaluate the value of ADC and Lip/(Cho + Cr) in the differential diagnosis of musculoskeletal lesions and to determine the relation between ADC and Cho/Cr ratio. Methods and Materials: A total of 52 patients with musculoskeletal tumors, 28 malignant and 24 benign confirmed by histology, were examined on a 1.5-T MR scanner. Diffusion-weighted image (DWI) and 1H-MRS sequences were performed. Quantitative analysis was performed using region of interest (ROI) measurements and calculation of a bone marrow. Peaks of Cho, Cr and Lip were observed in 1HMRS, and the ADCs of the tumors were calculated using three different b values, 0, 300 and 600 s/mm2. The correlation between tumor ADCs and Cho/Cr was analyzed by Pearson correlation test. Results: ADCs in benign tumors were significantly higher than those of malignant tumors (P .001). The Lip/(Cho+Cr) in benign tumors were significantly higher than those of malignant tumors (P .001). The chemical shift of the lipid peak is between 1.5-2.09 ppm. There was an inverse correlation between ADC and Cho/ Cr (r=0.426, P 0.01) Conclusion: ADC and Lip/(Cho+Cr) are useful in the differential diagnosis of benign and malignant musculoskeletal tumors. Tumor ADC correlates inversely with tumor Cho/Cr. DWI is sensitive and 1H-MRS is reliable in the diagnosis of musculoskeletal tumors. Combined use of ADC and 1H-MRS will enhance the diagnostic accuracy accordingly. B-002 10:39 Diagnostic impact of echo planar diffusion-weighted magnetic resonance imaging (DWI) in characterization of musculoskeletal soft tissue masses using apparent diffusion coefficient (ADC) mapping as a quantitative assessment tool R. Warda, A. EL Sherief, K. Batterjee; Jeddah/SA ([email protected]) Purpose: To elicit the diagnostic impact of echo planar DW imaging in distinguishing benign from malignant musculoskeletal soft tissue masses using ADC mapping as a quantitative assessment tool. Methods and Materials: The study included forty-two patients presented with musculoskeletal soft tissue masses according to clinical or previous imaging findings. Echo Planar DW imaging using diffusion gradient strengths yielding b-values (0, 250, 500 and 1000 seconds/mm2) were performed in addition to standard MR protocols. MR imaging data were analyzed regarding the location, signal intensity changes and pattern of enhancement of the lesion. The ADCs of the lesions were calculated and compared with the histopathological findings. Results: Histopathological findings revealed 22 benign lesions. On other hand, 20 malignant tumors were proved. The mean ADC value of all benign soft lesions was 1.76 p0.24 while that of all malignant lesions was 1.21p0.18. For benign lesions, the highest ADC value was seen in ganglion (2.9 p 0.43), while the lowest one was seen in aggressive fibromatosis (0.35 p0.04). For malignant lesions, the highest ADC value was seen in liposarcoma (1.8p0.25), the lowest ADC value was seen in fibrosarcoma (0.9p0.16). Conclusion: ADC measurement of soft tissue masses is promising as a noninvasive tool in differentiation of benign and malignant soft tissue lesions, providing additional information in characterizing the soft tissue masses but do not replace the routine MRI sequences. Further prospective studies with larger scale of patient populations using optimized diffusion imaging sequences may be required. S142 A B 10:48 Value of 4D-MR angiography in the evaluation of soft tissue tumors S. Lecocq, M. Louis, C. Baumann, T. Batch, R. Detreille, D. Roch, A. Blum; Nancy/FR ([email protected]) Musculoskeletal B-001 B-003 C D E F G F H Purpose: To evaluate the performance of 4D-MRA in the staging and grading of soft-tissue tumors. Methods and Materials: Fifty-nine soft-tissue masses underwent classic and dynamic contrast material-enhanced with 4D-MRA (TRICKSВ®, GE) MR imaging. Diagnosis was based on histologic findings (n=39) or results of all imaging procedures with clinical follow-up of at least 6 months (n=20). Two independent reviewers evaluated the dimensions, location (compartment), vascular and nervous invasions, and dynamic enhancement of the tumors. The degree of interobserver and intertechnique agreements was calculated. A univariate and multivariate logistic regression analysis was used to identify the TRICKS parameters that might be predictive of malignancy. Results: The interobserver and intertechnique agreements were good or excellent for all the parameters except for the analysis of liquefaction. The most discriminating parameters to predict malignancy were the peripheral enhancement, the type 5 of time intensity curve and a short time to peak of the tumor. The TRICKS sequence had a very high accuracy in the detection of vascular invasion, but due to the low prevalence of this sign, this finding was of relatively low value to predict malignancy. Conclusion: TRICKS should be added to standard MRI for pre-therapeutic evaluation of soft tissue tumors when vascular invasion is suspected. B-004 10:57 MR imaging features of skeletal muscle lymphoma C. Chun, W.-H. Jee, H. Park, S.-H. Lee, Y. Kim, J.-M. Park, S.-H. Park; Seoul/KR Purpose: To describe the findings of MR imaging of skeletal muscle lymphoma. Methods and Materials: The MR images of pathologically proven lymphoma of the skeletal muscle were analyzed for patterns of muscle abnormal signal and contrast enhancement, relative preservation of intramuscular fat planes, fascia involvement pattern, and subcutaneous and skin abnormalities. Six patients with direct extension from lymphoma of bone were excluded. Results: There were nine patients with primary muscle lymphoma and eight patients with muscle metastasis from systemic lymphoma. Skeletal muscle lymphoma presented as an intramuscular mass in 11 cases (65%) or muscle abnormal signal in 6 cases (35%). Extensive adjacent abnormal signal was observed in eight patients (73%) with intramuscular mass. Muscle enlargement and some remaining intramuscular fat planes were observed in all cases. A total of 14 (82%) cases showed traversing vessels within muscle involvement. All lesions showed intermediate signal on T1-weighted images. On T2-weighted images, all lesions showed intermediate signal with diffuse involvement, except for one patient with predominantly peripheral thick band-like abnormal signal in the muscles. Among the contrast-enhanced T1-weighted imaging of 16 patients, skeletal muscle lymphoma showed diffuse enhancement in 10 patients (63%), predominantly peripheral thick band-like enhancement in 4 patients (25%) and marginal septal enhancement in 2 patients (13%). Thick irregular enhancement of deep fascia or superficial fascia was observed in 13 patients (93%) or 12 patients (86%), respectively. There were subcutaneous stranding (n = 13) and skin involvement (n = 3). Conclusion: Skeletal muscle lymphoma has distinguishing MR features that help to differentiate muscle lymphoma from other soft tissue tumors and tumor-like lesions. B-005 11:06 Differentiating high-grade from low-grade chondrosarcoma with MR imaging H. Yoo 1, S. Hong1, J.-Y. Choi1, K. Moon1, N. Kim1, J. Lee2, J.-A. Choi2, H. Kang2; 1 Seoul/KR, 2Sungnam/KR ([email protected]) Prupose: To evaluate the MR-imaging features to differentiate between high-grade and low-grade chondrosarcoma and to determine predictors for this differentiation. Methods and Materials: MR images of 42 pathologically proven chondrosarcomas (28 LGCSs and 14 HGCSs) were retrospectively reviewed. There were 13-male and 29-female patients with an age range of 23-72 years. On MR images, signal intensity, contrast enhancement pattern, soft tissue mass formation and specific morphologic characteristics including internal lobular architecture, outer lobular margin and entrapped fat were analyzed. MR-imaging features to identify HGCS and LGCS were compared by means of univariate analysis and multivariable stepwise logistic regression analysis. Scientific Sessions B-006 11:15 Imaging patellar tumors: Retrospective study of 32 cases R. Rinaldi, D. Vanel, R. Casadei, M. Alberghini, M. Mercuri, U. Albisinni; Bologna/IT ([email protected]) Purpose: From 1916 and among 23000 musculo-skeletal tumours, 41 involved the patella. The aim of the study is to show the imaging patterns to help the diagnosis. Methods and Materials: Thirty-two had imaging studies (radiographs: 30, CT: 18, MR: 9) and histology that were reviewed. There were 13 females, 19 males, from 11 to 68 years old. Benign tumors were seven giant cell tumors, five chondroblastomas, six osteoid osteomas, two aneuvrismal bone cysts, one angioma, and one mucoid cyst. Malignant tumors were four metastases, one lymphoma, one plasmocytoma, and one angiosarcoma, There were also three hemangioendotheliomas. Results: Chondroblastomas had thin and partially interrupted cortex in two cases; in the other case, it was destroyed. Giant cell tumors were purely lytic and more aggressive. The nidus of osteoid osteomas was always easily detected, even on radiographs. Fluid levels were obvious on MR in the aneuvrismal bone cyst. The primary tumor was known in three cases of metastases. Partial destruction of the patella and huge soft tissue mass were seen in the lymphoma. The three hemangioendoteliomas had multiple poorly defined lesions of the knee. Conclusion: Patellar tumors are rare, and usually benign. As the patella is an apophysis, the most frequent lesions are giant cell tumor in the adult, chondroblastoma in the younger. Osteoid osteomas are easily diagnosed. Multiple local lesions are seen in vascular tumors and secondary malignancies. Lesions are easily analysed on radiographs. CT and MR define better the cortex, soft tissue extension, and fluid levels. B-007 11:24 Input of ultrasonography for the exploration of subungual glomus tumors of fingers: Retrospective study of 21 tumors J. Rousseau, H. Guerini, E. Pluot, D. Richarme, A. Feydy, A. Chevrot, J.-L. DrapГ©; Paris/FR ([email protected]) Purpose: To retrospectively compare efficiencies of ultrasonography and MRI in pre-operative assessment of subungual glomus tumors. Methods and Materials: 21 subungual glomus histologically confirmed tumors were analysed with ultrasonography and MRI. The results obtained by the two techniques were compared. The parameters were the detection of the tumor (s), the number, size, location of the tumor (s), margins analysis, power Doppler signal, post-gadolinium enhancement, and presence of bone erosion. Results: Nineteen percent (n=19/21) of the tumors were detected using ultrasonography, 100% were detected by MRI. The average tumor size was 3 mm with both ultrasonography and MRI. Correlation between US and MRI estimates of tumor’s location in axial (kappa = 0.909) and sagittal (kappa = 1) plane was excellent. None of the observed tumors was hypovascularised with MRI, whereas 4 out of 19 (21%) appeared hypovascularised with power Doppler ultrasonography. The two tumors that were not detected using ultrasonography consisted in two tinny (1.7 mm both), ill defined margins tumors without bone erosion. Conclusion: Ultrasonography turns out to be reliable in the preoperative assessment of sub-ungual glomus tumors. It could be proposed as a first step method to confirm the diagnosis and assess the extension of the tumor (s). MRI could then be proposed in case of disagreement between the ultrasonography results and the clinical diagnosis. B-008 11:33 Diagnostic value of whole body magnetic resonance imaging and bone scintigraphy in the detection of osseous metastases in patients with breast cancer: A randomized, double-blinded and prospective study at two hospital centres S. Ohlmann1, M. Kirschbaum1, G. Fenzl2, D. Pickuth1; 1Saarbruecken/DE, 2 PГјttlingen/DE ([email protected]) Purpose: To evaluate for the first time in a randomized, double-blinded and prospective approach the diagnostic accuracy of whole body MR imaging (WB-MRI) and bone scintigraphy (BS) in the detection of bone metastases in a large and homogeneous patient group with breast cancer. Methods and Materials: 213 patients with breast cancer were examined for bone metastases by WB-MRI and BS. Under standardized conditions the examinations were performed separately at two different hospital sites. The images were reviewed independently by two radiologists and two nuclear medicine specialists. Results: In 141/213 patients (66%), WB-MRI and BS were concordantly negative; in 4/213 patients (2%), both WB-MRI and BS demonstrated bone metastases. There were discrepant findings in 14 cases. In 7 cases with normal WB-MRI, there were false positive findings in BS. In 5 cases with normal bone scans, WB-MRI revealed bone metastases. In 89% of patients with equivocal bone scans, WB-MRI confidently excluded bone metastases. The sensitivity, specificity and positive and negative predictive values of WB-MRI were 90, 94, 82 and 98%, respectively, and those of BS were 40, 82, 36 and 91%, respectively. Conclusion: WB-MRI has a much higher diagnostic accuracy in the detection of osseous metastases than BS. These results have a major impact on both the national and international guidelines on the diagnosis, therapy and follow-up of breast cancer. WB-MRI should be given clear priority to BS in the diagnosis and follow-up of bone metastases in these patients. B-009 11:42 Value of whole-body MRI in correctly staging monoclonal plasma cell disease: Comparison of the Durie/Salmon and the Durie/Salmon PLUS staging system K. Fechtner, J. Hillengass, L. Grenacher, S. Delorme, H.-U. Kauczor, M.-A. Weber; Heidelberg/DE ([email protected]) Purpose: Whole-body MRI (wb-MRI) was used to investigate the concordance of the Durie/Salmon (D/S) with the Durie/Salmon PLUS (D/S PLUS) staging system regarding focal or diffuse infiltration in all stages of monoclonal plasma cell disease. Methods and Materials: A total of 403 untreated patients (22-86 years) with monoclonal gammopathy of undetermined significance (MGUS, n = 84), plasmacytoma (n = 17), amyloidosis (n = 12) and multiple myeloma in all stages (MM, n = 325) were examined with wb-MRI on a 1.5 T-system using T1 and fat-suppressed T2-weighted sequences of the head, thorax, abdomen, legs, and spine yielding composed scans between the skull vertex and the feet excluding the distal forearms. Two blinded radiologists assessed in consensus the bone marrow infiltration pattern and focal lesions, and also distinguished between intraosseous, corticalis-exceeding, and soft tissue lesions with regard to D/S and D/S PLUS. Results: Six MGUS patients (7%) and 10 plasmacytoma patients (59%) showed focal lesions leading to an upgrading as MM stage IB (n = 12), IIA (n = 3) or IIIA (n = 1) in D/S PLUS. In 290 MM patients (all stages) only 8 patients (3%) would have been staged higher in D/S PLUS in comparison to D/S. In all amyloidosis patients wb-MRI led to no change in classification. Among all 403 patients of our population, 24 patients (6%) would have been staged higher in D/S PLUS when compared with D/S using wb-MRI. Conclusion: The classical D/S staging system is accurate in advanced disease, whereas in case of limited disease (MGUS, plasmacytoma) wb-MRI reveals more lesions and thus yields a more accurate classification. B-010 11:51 Normal spinal bone marrow and degenerative endplate changes: Perfusion MRI measurements related to age and sex L.A. Moulopoulos1, T.G. Maris2, A. Gouliamos1, L. Vlahos1, V. Savvopoulou1; 1 Athens/GR, 2Iraklion/GR ([email protected]) Purpose: To investigate differences in perfusion profiles of degenerative endplate marrow changes and normal bone marrow of patients matched for age and sex with perfusion MRI of the lumbosacral spine. Methods and Materials: Ninety-two consecutive patients referred for evaluation of low back pain or sciatica, without a history of malignant or chronic disease, underwent conventional MRI and perfusion MRI of the lumbosacral spine (group A). A B C D E F G H S143 Friday Results: On T1-weighted images, HGCSs (5 of 14) more frequently had high-signal intensity than LGCSs (1 of 28; P 0.05). HGCSs (9 of 14) commonly exhibited only peripheral enhancement, while most LGCSs (26 of 28) had peripheral and septal enhancement (P 0.01). HGCSs (10 of 14) more commonly lose the characteristic internal lobular structures within the tumor than LGCSs (4 of 28; P 0.01). Soft tissue formation was more frequently observed in HGCSs (11 of 14) than in LGCS (1 of 28; P 0.01). Entrapped fat within the tumor was seen in only 1 of 14 HGCSs, whereas 26 of 28 LGCSs had entrapped fat (P 0.01). Results of multivariable stepwise logistic regression analysis showed that soft tissue formation and entrapped fat within the tumor were the variables that could be used to independently differentiate HGCS and LGCS. Conclusion: There were several MR-imaging features of chondrosarcoma, which could be helpful in distinguishing HGCS from LGCS. Among others, soft tissue mass formation favored the diagnosis of HGCS, and entrapped fat within the tumor was highly indicative of LGCS. Scientific Sessions Fifty-two patients from group A, who had degenerative endplate marrow changes comprised group B. ROIs were placed on sites of normal marrow and degenerative changes on subtracted images. Time-intensity curves were generated for both groups and perfusion parameters (wash-in (WIN), wash-out (WOUT), time to maximum slope (TMSP), time to peak enhancement (TTPK)) were calculated. Both groups were stratified into males and females younger or older than fifty years and perfusion parameters for the two groups as well as for age- and sex-matched subgroups of normal and degenerative marrow were compared by means of student’s t-test. Sensitivity and specificity of perfusion parameters were evaluated with ROC analysis. Results: Perfusion parameters of degenerative changes differed significantly from those of normal marrow even when the two populations were matched for age and sex (p 0.05). Among all assessed perfusion parameters, a TTPK value 108 sec was most characteristic of degenerative changes (sensitivity 72.29%, specificity 84.57%). Conclusion: Perfusion MRI profiles of degenerative endplate marrow changes of the lumbosacral spine clearly differ from those of normal marrow regardless of patient’s age or sex and may reflect the underlying pathophysiologic changes. the results with those of PET and CT alone by correlating imaging findings with intraoperative staging. Methods and Materials: A total of 22 consecutive patients with PC from gastrointestinal (N=13) and ovarian cancer (N=8) and mesothelioma (N=1) underwent 18 F-FDG-PET/CT before surgery and HIPEC. In a retrospective analysis of PET, CT and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the peritoneal cancer index (PCI). Imaging results were correlated with the intraoperative PCI (13 regions) using Pearson’s correlation coefficient and linear regression analysis. Results: There was a strong and statistically significant correlation between the PCI obtained with PET/CT and the surgical PCI in the overall assessment (region 0-12, r=0.951, p 0.01) as well as in the regional analysis (region 0-8, r=0.703; region 9-12, r= 0.838) The correlation was lower for CT (region 0-12, r=0.919; region 0-8, r=0.666; region 9-12, r= 0.754) and PET alone (region 0-12, r=0.793; region 0-8, r=0.507; region 9-12, r=0.553). Conclusion: In comparison to PET and CT alone, combined 18 F-FDG-PET/CT yielded the best results in predicting PC and proved to be an useful tool for selecting candidates for peritonectomy and HIPEC. 10:30 - 12:00 B-013 Room C GI Tract SS 201a Gastrointestinal cancer: Detection and treatment response Moderators: S.A. Jackson; Plymouth/UK M. KantarcГЅ; Erzurum/TR B-011 10:30 Diffusion-weighted echo-planar MR images compared with late phase GdBOPTA-enhanced MR images in the detection of peritoneal implants G. Patriarca, A. Filippone, R. Cianci, R. Basilico, A. Tartaro, M.L. Storto; Chieti/IT ([email protected]) Purpose: To determine the usefulness of diffusion-weighted (DW) echoplanar MR imaging compared with late phase Gd-BOPTA-enhanced MR images in the detection of peritoneal implants. Methods and Materials: Twenty-three patients with known peritoneal implants underwent MR imaging at 1.5 T (Achieva, Philips). A single shot eco-planar diffusionweighted MR sequence was acquired using a unidirectional diffusion gradient with two b values (b0 and b500 sec/mm2). Apparent diffusion coefficient (ADC) was calculated for cerebrospinal fluid and for each peritoneal implant. A 3-D fat-saturated T1-weighted late phase Gd-BOPTA-enhanced sequence was also obtained after the completion of the dynamic study. Two radiologists evaluated MR images in two separate reading sessions: A. late phase Gd-BOPTA-enhanced images, B. late phase Gd-BOPTA-enhanced images combined with DW echoplanar images. Readers were asked to identify peritoneal implants, according to a four-point confidence scale. ADC values were also calculated in implants 1 cm in size. Results: A total of 92 lesions were identified during session A. Twenty-nine additional implants 1 cm in size were noted on the DW images. The mean ADCs (pSD) values were 1.18 p 0.48 mm2 /sec for the solid and 2.82 p 0.20 mm2 /sec for the cystic peritoneal implants. DW images significantly improved readers confidence level. Conclusion: Diffusion-weighted echo-planar MR imaging improves MR sensitivity in the detection of peritoneal implants. B-012 10:39 Value of 18 F-FDG-PET/CT to select patients with peritoneal carcinomatosis for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) C. Pfannenberg, P. Aschoff, I. KГ¶nigsrainer, M. Г–ksГјz, J.T. Hartmann, S. Miller, C.D. Claussen, A. KГ¶nigsrainer; TГјbingen/DE ([email protected]) Purpose: Extensive cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with significantly longer survival in patients with peritoneal carcinomatosis (PC). So far, no morphological imaging method has proven to accurately assess the intraabdominal tumor spread for adequate selection of candidates for radical cytoreductive surgery. The aim of our study was to predict the tumor load in patients with PC using 18 F-FDG-PET/CT and to compare S144 A B 10:48 Whole tumour quantitative measurement of first-pass perfusion of oesophageal squamous cell carcinoma using 64-slice MDCT: Correlation with microvessel density T.-W. Chen, Z.-G. Yang, Y. Li; Chengdu Sichuan/CN ([email protected]) C D E F G F H Purpose: To optimize a first-pass perfusion protocol with 64-slice MDCT for determination of whole tumour microcirculation of esophageal squamous cell carcinoma, and to assess correlations between perfusion parameters and microvessel density (MVD). Methods and Materials: Thirty-one patients with surgically oesophageal squamous cell carcinomas were enrolled into our study, and subdivided into subgroups according to status of lymph node metastasis. All patients underwent whole tumour perfusion scan with 64-slice MDCT. Perfusion parameters, including perfusion (PF), peak enhanced density (PED), blood volume (BV) and time to peak (TTP) were measured. Postoperative tumour specimens were assessed for MVD. Differences in perfusion parameters or MVD between subgroups were compared by Student t-test. Pearson correlation coefficient tests were performed to determine correlations between perfusion parameters and MVD. Results: Mean values for PF, PED, BV and TTP of the whole tumour were 28.85p20.29 ml/min/ml, 23.16p8.09 Hu, 12.13p5.21 ml/100 g, and 35.05p13.85 sec, respectively. Mean MVD in whole tumour at magnification (Г—200) was 15.75p4.34 microvessel/tumour sample (vessels/0.723 mm2). Between patients with and without lymph node metastasis, no statistical significances were found in perfusion parameters (p 0.05), whereas there were statistical significances in MVD (p 0.05). PED and BV were correlated with MVD (r=0.651 and r=0.977, respectively, all p 0.05). However, PF and TTP were not correlated with MVD (r=0.070 and r=0.100, respectively, all p 0.05). Conclusion: First-pass perfusion technique at 64-slice MDCT could be valuable to assess whole tumour microcirculation of oesophageal squamous cell carcinoma. B-014 10:57 The spatial pattern of colorectal tumour and normal bowel perfusion estimated using perfusion CT and two-dimensional fractal analysis: Feasibility and repeatability B. Sanghera1, V.J. Goh1, D. Wellsted2, I. Przybytniak2, S. Halligan3; 1 Northwood/UK, 2Hatfield/UK, 3London/UK ([email protected]) Purpose: To evaluate the feasibility and repeatability of fractal analysis for assessing the spatial pattern of colorectal tumour and normal bowel perfusion obtained at CT. Methods and Materials: Twenty patients with colorectal adenocarcinoma underwent a 65-second perfusion CT study from which a perfusion parametric map was generated using validated commercial software (GE Healthcare). The tumour was identified by a radiologist, segmented via thresholding, and fractal analysis applied using in-house software: fractal dimension, abundance and lacunarity were assessed for the entire outlined tumour, and for selected representative areas within the tumour of low and high perfusions. Comparison was made with 10 patients with normal colon (controls), processed in a similar manner, using two-way mixed analysis of variance. Image analysis was repeated in 10 patients from each group ( 3 months between analyses) to assess measurement repeatability using BlandAltman statistics. Significance was at the 5% level. Results: Fractal values were significantly higher in cancer than normal colon: mean (SD) 1.71 (0.07) versus 1.61 (0.07) for fractal dimension (FD); 1.61 (0.07) and 7.82 Scientific Sessions B-015 11:06 Gastrointestinal 18 F-FDG accumulation in PET/CT without corresponding morphological mass: Early predictor of cancer development? T. Heusner, U.-H. Kim, S. Hahn, M. Forsting, A. Stahl, G. Antoch; Essen/DE ([email protected]) Purpose: Focal gastrointestinal FDG uptake can frequently be found on FDG-PET/ CT even in patients without known gastrointestinal malignancy. The aim of this study was to evaluate whether increased gastrointestinal FDG uptake may identify patients at risk for developing gastrointestinal malignancies. Methods and Materials: A total of 681 patients without a history or CT-based evidence of esophagogastric or anorectal diseases underwent whole-body FDG-PET/ CT. The esophagogastric junction, the gastric wall, the wall of the rectal ampulla and the anal canal were evaluated qualitatively and quantitatively for increased FDG uptake. Patients with elevated FDG uptake on qualitative evaluation were grouped into group A and patients without increased FDG uptake were assigned to group B. Differences between the SUVmax were tested for significance by MannWhitney Wilcoxon’s test (P 0.05). Clinical and radiological follow-up (mean: 894 d p 473 d) served as the gold standard to determine whether patients developed gastrointestinal malignancies. Results: Gastroesophageal junction: mean SUVmax group A: 4.16, group B: 3.11; P 0.001. None of the patients developed a gastroesophageal malignancy. Gastric wall: mean SUVmax group A: 3.87, group B: 3.19; P = 0.004. One patient of group B developed gastric cancer on follow-up. Rectal ampulla: mean SUVmax group A: 3.9, mean SUVmax group B: 3.0; P = 0.011. No patient developed rectal malignancies. Anal canal: mean SUVmax: 3.9, mean SUVmax group B: 2.7; P 0.001. No patient developed anal malignancies. Conclusion: Elevated esophagogastric or anorectal FDG uptake of patients without known malignancies and without suspicious CT findings at these sites does not predict malignancy. B-016 11:15 Assessment of tumor microcirculation in rectum carcinoma with regard to different pharmacokinetic models, intra-tumor heterogeneity and therapeutic effects after neoadjuvant radio-chemotherapy A.M. HГ¶tker, P. Mildenberger, T. Junginger, C. DГјber, T. Hansen, M. Menig, A. Heintz, K. Oberholzer; Mainz/DE ([email protected]) Purpose: Measurement of changes in DCE- MRI parameters of rectum carcinoma patients before and after neoadjuvant radio-chemotherapy using two slices per patient and measurement to compare the assessed results of different models (Brix/Tofts) between each other and the different slices. Methods and Materials: DCE- MRI measurements of 30 patients with rectum carcinoma were performed on a 1.5 T MR system (TurboFLASH, FoV: 350 mm, Matrix: 256x192, Slice: 7 mm, TR/TE/TI: 7.0/3.86/120 ms, Flip angle 12В°, 200 Hz/px Bandwith, Voxel size 1.37x1.37x7 mВі) during intravenous contrast media application before and after neoadjuvant radio-chemotherapy. For each measurement, two slices were applied in maximal tumor extent. The resultant images were analyzed semi-quantitatively and quantitatively (Brix and Tofts compartment models). Results: Significant changes were found for several parameters including the semi-quantitative time to peak (TTP, p 0.001) and the quantitative values kep from the Brix model (p 0.001), K from the Tofts model (p 0.001) and AuCtP (area under the curve till maximum enhancement, p 0.001). The percentage decrease in exchange rate parameters of the applied pharmacokinetic models was similar (both kep and K decreased about 50%). The two slices applied in maximal tumor extent showed no significant different results. Conclusion: Neoadjuvant radio-chemotherapy results in a significant change of tumor microcirculation. Neither the slice selection in the maximal tumor extent affected the results in later analysis nor was it possible to find a relevant difference in therapeutic effects between the corresponding parameters of the pharmacokinetic models. B-017 11:24 Value of diffusion weighted MR imaging for predicting tumour response to chemoradiation therapy in patients with advanced rectal cancer D.M.J. Lambregts1, C. Matos2, S. Gourtsoyianni3, A.G. Kessels1, G.L. Beets1, M. Maas1, J.E. Wildberger1, R.G.H. Beets-Tan 1; 1Maastricht/NL, 2Brussels/BE, 3 Iraklion/GR ([email protected]) Purpose: Preoperative knowledge of good response to chemoradiation (CRT) in locally-advanced rectal cancer (LARC) could allow selection for local excision without compromising risk for local recurrence. Therefore selection between ypT0-2 and ypT3 is important. This study aims to evaluate the potential of diffusion weighted MR-imaging (DWI) of rectal cancer for selecting these patients preoperatively. Methods and Materials: 36 LARC-patients undergoing neoadjuvant CRT followed by surgery were evaluated retrospectively. All patients underwent MR-imaging, including T2W-FSE, prior and subsequent to CRT. Pre-CRT MRI included DWI. Pre-CRT apparent diffusion coefficient (ADC)-measurements of all tumours were performed. Tumour-volume reduction was assessed on pre- and post-CRT images. Histology was the reference for T-stage. Mann-Whitney and ROC-curve analyses were performed to assess value of pretreatment ADC-values for predicting reduction in tumour-volume and histological outcome. Results: ADC-values were significantly lower in tumours with 75% downsizing after CRT as compared to those with little downsizing (mean 651 vs 869 mm2/s, p=0.002). ADC-values were also lower in tumours downstaged to ypT0-2 as compared to those with no downstaging. (mean 669 vs 821 mm2/s, p=0.04). Area under the ROC-curve for combined assessment of volume reduction and ADCvalues for prediction of downstaging to ypT0-2 was 0.800, compared to 0.699 for ADC-measurements only. Conclusion: 1. Diffusion weighted MRI could aid in selection of patients, and likely to show good response to neoadjuvant treatment. 2. Low primary ADC-values correspond with good response to CRT. 3. Combined assessment of primary ADC and volume-reduction after CRT could be useful for prediction of tumourdownstaging to ypT0-2. B-018 11:33 Role of DWI images in the evaluation of tumor regression grade after chemoradiation treatment in patients with rectal cancer: Comparison with 18 FDG-PET-CT study D. Ippolito1, L. Guerra1, F. Invernizzi2, S. Sironi1, F. Fazio3, C. Messa1; 1Monza/IT, 2 Lecco/IT, 3Milan/IT ([email protected]) Purpose:To compare the diagnostic performance of MR diffusion imaging with 18FDG PET/CT in determining the response to chemoradiation therapy, in patients with locally advanced rectal cancer (LARC). Methods and Materials: A total of 23 patients with histologically proven diagnosis of rectal carcinoma were enrolled in our study. All the patients underwent a whole body 18-FDG PET/CT scan and a pelvic MR examination including DW-imaging for staging (PET1, MR1) and after chemoradiation therapy (PET2, MR2). Then, all the patients underwent total mesorectal excision and the histological results were compared with imaging findings. MR scanning was performed on 1.5 T magnet, including T2-weighted multiplanar imaging and in addition DW-images with b-value of 0 and 1,000 mmВІ/sec. On PET/CT, SUVmax of rectal lesion was calculated for PET1 and PET2 with the determination of percentage variation of SUVmax ($SUV). Results: Primary tumor was detected in all the patients at both MR imaging and FDG-PET/CT. On DWI, the tumor appeared as high signal intensity as compared with the normal rectal wall. Mean ADC values were on MR1: 0.86 p 0.22 x 10-3 mmВІ/ sec and on MR2: 1.43 p 0.25 x 10-3 mmВІ/sec. Mean SUV-max values calculated at the same position were respectively 16.22 p 9.05 and 4.5 p 2.5. After neoadjuvant therapy, all patients underwent surgery. In accordance with Mandard's criteria, 16 out of 23 patients were considered to be responders (TRG1 and TRG2), while the remaining were considered to be non-responders. The mean values of SUVmax in PET1 was higher than the mean value of SUV-max in PET2 (P 0.001), whereas the mean ADC values were lower in RM1 than in RM2 (P 0.001), with a $SUV and $ADC respectively of 67 and 69%, obtaining correlation between TRG, $SUV and $ADC. Conclusion: DWI is an effective diagnostic tool in the evaluation of rectal cancer response after chemoradiotherapy and has an accuracy rate similar to that of 18 FDG PET/CT. A B C D E F G H S145 Friday (0.62) and 6.89 (0.47) for fractal abundance (FA; p= 0.001). Fractal values were lower in 'high' than 'low' perfusion areas. Lacunarity curves were shifted to the right for cancer compared with normal colon. Repeatability was good with a within subject coefficient of variation of 0.005-0.08; and repeatability coefficient of 1.6-22%. Conclusion: Colorectal cancer perfusion mapped by CT demonstrates fractal properties, which is different to normal bowel. Fractal analysis is repeatable providing an in vivo quantitative measure of the spatial pattern of perfusion. Scientific Sessions B-019 10:30 - 12:00 11:42 Added value of diffusion-weighted imaging for prediction of complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer S. Kim, J. Lee, S. Hong, G. Kim, J. Lee, J. Han, B. Choi; Seoul/KR ([email protected]) Purpose: To evaluate the added value of diffusion-weighted imaging (DWI) in predicting the complete response (CR) to neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer. Methods and Materials: A total of 40 consecutive patients (28 men, 12 women; mean age, 58 years; range, 39-75 years) with locally advanced rectal cancer, who underwent neoadjuvant CRT and subsequent surgery, were enrolled in this retrospective study. All patients underwent pre- and post-CRT 1.5-T rectal MRI plus post-CRT DWI. For qualitative analysis, two blind radiologists independently reviewed both the conventional MRI and the combined image set of MRI with DWI at a 2-week interval and recorded their confidence level using a five-point scale for the CR to neoadjuvant CRT. The diagnostic accuracy for each reviewer was calculated using ROC analysis. For quantitative analysis, the third radiologist measured the apparent diffusion coefficient (ADC) values of the region of interest three times. The mean ADC values were compared between the CR group and the non-CR group. Pathology reports served as the reference standard. Results: The diagnostic accuracy (Az) for predicting the CR was significantly improved after the additional review of DWI for both reviewers (for reviewer 1, 0.676 versus 0.876, P = 0.005; for reviewer 2, 0.658 versus 0.815, P = 0.036, respectively). The mean ADC (1.62 Г—10-5 cm2/s) of the CR group (n = 11) was significantly higher than that (1.04 Г—10-5 cm2/s) of the non-CR group (n = 29; P 0.0001; t-test). Conclusion: Adding DWI to conventional MRI provides better diagnostic accuracy than conventional MRI alone for predicting the CR to neoadjuvant CRT for locally advanced rectal cancer. B-020 11:51 Locally advanced rectal cancer (LARC): Role of 18-FDG PET/CT in evaluation of response to neoadjuvant radiochemotherapy D. Ippolito1, L. Guerra1, F. Invernizzi2, S. Sironi1, C. Messa1, F. Fazio3; 1Monza/IT, 2 Lecco/IT, 3Milan/IT ([email protected]) Purpose: To assess the value of 18-FDG PET/CT in evaluationof rectal cancer response to neoadjuvant chemoradiation therapy. Methods and Materials: A total of 23 patients with locally advanced primary rectal cancer were enrolled in our study. All the patients underwent a diagnostic staging with 18-FDG PET/CT before (PET 1) and 1 month after the chemoradiation treatment (PET 2). Images were correlated with pathological features by tumor regression grading. For each examination, the mean value of SUVmax was calculated in PET 1 and PET 2. The percentage of SUVmax decrease, from baseline to presurgical examination, was also evaluated ($SUV) and correlated with pathologic response classified as tumor regression grade score (TRG). Pathologic TRG values were obtained in accordance to Mandard classification (TRG 1 = complete regression; TRG 5 = absence of regression). Results: All the patients underwent total mesorectal excision after preoperative treatment. Out of 23 patients, 16 were considered to be responders (9 with TRG 1; 7 with TRG 2), while the remaining 7 patients were considered to be non-responders (5 with TRG 3; 2 with TRG 5). The mean value of SUVmax PET 1 was: 17.5 p 9.4, being significantly higher (P 0.001) than the mean value in PET 2: 4.3 p 2.5. The percentage of reduction of SUV ($SUV) after chemoradiation therapy was 67%. A significant correlation (linear regression) was found between TRG and SUVmax in PET2 (P 0.001) and also between TRG and $SUV (P 0.05). Conclusion: The 18-FDG PET/CT has a role as prognostic tool in the evaluation and prediction of neoadjuvant CRT response in patients with locally advanced rectal cancer. S146 A B C D E F G F H Room E1 Contrast Media SS 206 New perspectives in contrast-enhanced imaging Moderators: E. Di Cesare; LвЂ�Aquila/IT T. Persigehl; MГјnster/DE B-021 10:30 Superparamagnetic iron oxide-enhanced diffusion-weighted magnetic resonance imaging for assessment of small ( 1 cm) malignant focal lesions in the liver D. Kim, J. Yu; Seoul/KR Purpose: To retrospectively compare the diffusion-weighted imaging (DWI) before and after superparamagnetic iron oxide (SPIO) injection during the hepatic MRI for assessment of sub-centimeter malignant lesions in the liver. Methods and Materials: Eight patients with 19 hepatocellular carcinomas (HCCs) and 12 patients with 35 hepatic metastases were enrolled at a single institution between June 2007 and March 2008. All lesions were smaller than 1 cm. Hepatic metastases were detected on SPIO-enhanced T2- and T2*-weighted images and SPIO-enhanced T2- and T2*-weighted images were used as a reference standard for the confirmation of hepatic metastases. All HCCs were confirmed by either surgery, iodized oil accumulations after chemoembolization or increased size during the short-term follow-up. Pre- and post-SPIO-enhanced DWI (b values of 50, 400 and 800 s/mm2) was performed by 1.5 T MRI unit. Confidence score of each lesion on pre-contrast DWI (pre-DWI) and ferucarbotran-enhanced DWI (SPIO-DWI) were rated by two independent radiologists using five-grade scales. The Wilcoxon signed rank test was used to differentiate the techniques. Results: Compared to pre-DWIs (mean 3.76, 3.54, 3.28 for b = 50, 400, 800 s/mm2), SPIO-DWIs (mean 4.19, 4.04, 3.78 for b = 50, 400, 800 s/mm2) revealed higher confidence scores. SPIO-DWIs (b = 400 and 800 s/mm2) showed significantly higher confidence scores than pre-DWIs (b = 400 and 800 s/m m2; P 0.05). Conclusion: SPIO-enhanced DWI is an easily applicable method for detection of sub-centimeter malignant lesions in patients with malignancy and liver cirrhosis and is superior to DWI. B-022 10:39 Normal dynamic contrast enhancement patterns of the upper abdominal organs after administration of gadolinium-EOB-DTPA in comparison to gadolinium-BT-DO3 A J.P. KГјhn, K. Hegenscheid, R. Puls, N. Hosten; Greifswald/DE ([email protected]) Purpose: To investigate whether dynamic MRI of the upper abdominal organs, with gadolinium-EOB-DTPA, a hepatobiliary contrast agent, has sufficient contrast enhancement patterns such as extracellular contrast agents. Methods and Materials: Dynamic gadolinium-EOB-DTPA enhanced MR-imaging of pancreas, spleen, kidney, liver and abdominal aorta was performed in 50 patients. A gadolinium-BT-DO3 A enhanced MRI control group of 50 patients was added. Dynamic imaging, using a T1-weighted VIBE gradient-echo sequence (3.35/1.35 [TR/ TE], 12В° flip angle), was performed before, 20 sec (arterial), 55 sec (portal venous) and 90 sec (hepatic venous) after a bolus injection of gadolinium-EOB-DTPA (0.25 mol/l) or gadolinium-BT-DO3 A (1.0 mol/l). Enhancement index was calculated for each organ and time. Both groups were compared and analysed statistically. Results: All MR-examinations of both groups were of diagnostic quality. During the early dynamic phases significant lower mean enhancement indices were observed in the gadolinium-EOB-DTPA group than in the gadolinium-BT-DO3 A group: pancreas (pv: 0.66, 1.39, pb0.001; ven: 0.51, 1.36, pb0.001), spleen (pv: 1.54, 2.41, pb0.001; ven: 1.19, 2.23, pb0.001), renal cortex (pv: 1.76, 2.63, pb0.001; ven: 1.60, 2.63, pb0.001), and liver (pv: 0.76, 0.94, p=0.016; ven: 0.76, 1.04; pb0.001). In the abdominal aorta the mean enhancement index was higher after bolus injection of gadolinium-EOB-DTPA (art: 3.33, 2.23; pb0.005). Conclusion: In early dynamic MR-images of the upper abdominal organs higher gadolinic concentration of gadolinium-BT-DO3 A has a significant benefit compared to the liver cell specific contrast agent gadolinium-EOB-DTPA. Higher protein binding resulting in increasing relaxivity of gadolinium-EOB-DTPA compensates the low gadolinium concentration in the abdominal aorta. Scientific Sessions B-023 10:48 Imaging delay for optimum detection of colorectal liver metastases using Gd-EOB-DTPA (PrimovistВ®)-enhanced MRI N. Bharwani1, A.M. Riddell2, T. Wallace2, E. Scurr2, D.-M. Koh 2; 1London/UK, 2 Sutton/UK B-024 10:57 The late phase of contrast-enhanced ultrasonography (CEUS) and magnetic resonance imaging (MRI) with hepatospecific contrast material (Gd-BOPTA) in the characterization of solid focal liver lesions A. Gallotti1, M. D’Onofrio2, V. Cantisani3, F. Calliada1, R. Pozzi Mucelli2; 1Pavia/IT, 2 Verona/IT, 3Rome/IT ([email protected]) Purpose: To compare the late phase of CEUS with the hepatobiliary phase of CE-MR with Gd-BOPTA in the characterization of solid focal liver lesions in terms of benignity and malignancy. Methods and Materials: A total of 147 solid focal liver lesions (38 focal nodular hyperplasias, 1 area of focal steatosis, 3 regenerative nodules, 8 adenomas, 11 cholangiocarcinomas, 36 hepatocellular carcinomas and 49 metastases) were retrospectively evaluated in a multicentric study, both with CEUS and CE-MR performed with Gd-BOPTA (Multihance, Bracco, Milan, Italy). All the hypo-echoic/ intense lesions were considered malignant. Lesions thought to be malignant were cito-hystologically proven. Lesions thought to be benign were followed-up. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and accuracy were calculated for the late phase of CEUS and for the hepatobiliary phase of CE-MR, respectively, and in association. Results: There were 42 benign focal liver lesions and 105 malignant. The diagnostic errors were 13 of 147 (8.8%) by CEUS and 12 of 147 (8.2%) by CE-MR. Sensitivity, specificity, PPV, NPV and accuracy of the late phase of CEUS were 90, 93, 97, 80 and 91%, while of the hepatobiliary phase of CE-MR were 91, 93, 97, 81 and 92%, respectively. If we considered both techniques, the misdiagnosis diminished to 3 of 147 (2%) and sensitivity, specificity, PPV, NPV and accuracy were 98, 98, 99, 95 and 98%. Conclusion: The association between the late phase of CEUS and the hepatobiliary phase of CE-MR is more accurate than the two techniques separately in the characterization of solid focal liver lesions in terms of benignity and malignancy. B-025 11:06 Contrast-enhanced ultrasound after direct intraarterial contrast injection for guiding endovascular liver-directed therapies G. Bizzarri, V. Anelli, D. Valle, S. de Nuntis, A. Bianchini; Albano Laziale/IT ([email protected]) Purpose: We propose contrast-enhanced ultrasound (CEUS) after direct intraarterial injection of US contrast as a guiding tool of TACE and precision TACE, because it allows a precise visualization of the territories fed by the cannulated artery. B-026 11:15 The use of contrast-enhanced ultrasound for the characterization of neovascularization in carotid atherosclerotic plaques D.-A. Clevert, T. Saam, W. Sommer, M.F. Reiser; Munich/DE ([email protected]) Purpose: To evaluate the use of contrast-enhanced ultrasound in the neovascularization of carotid atherosclerotic plaques. Methods and Materials: A total of 33 patients with kown atherosclerotic plaques in the carotid artery were examined with contrast-enhanced ultrasound to evaluate the features of neovascularization within this plaque. Additionally, these plaques were analyzed and correlated with plaque size and echogenicity. For contrast-enhanced ultrasound, we injected 2.4 cc of SonoVue (Bracco, Italy) i.v. The examinations were performed using the Sequoia 512 (Siemens / Acuson, Mountain View) with a 15 Mhz or 17 Mhz probe by using the CPS software. Results: There were 41 atherosclerotic plaques, 27 of which (19 soft and 8 mixed) enhanced after injection of SonoVue. The enhancement occurred from the carotid wall to the center of the plaque with a short-line pattern in 15 plaques, whereas 12 plaques enhanced from both the carotid wall and the carotid lumen, with just a little spot pattern. The arrival time of contrast was later in the plaques than in the carotid artery and the time to peak was longer in the plaques than in the carotid lumen. Among the 14 unenhanced plaques, 4 were hard, 3 were calcified, 2 were soft, and 5 were mixed. The unenhanced plaques had a thickness of 2.7 mm. Conclusion: In our small patient population, contrast-enhanced ultrasound allows the dynamic evaluation of neovascularization within carotid plaques and neovascularization may correlate with plaque morphology. B-027 11:24 Contrast enhanced ultrasound (CEUS) in the assessment of antiangiogenic effects: Early prediction of the anticancer activity of bevacizumab in a mouse xenografted model R. Watanabe, T. Munemasa, M. Matsumura; Tokyo/JP ([email protected]) Purpose: To investigate the feasibility of CEUS for prediction of the anticancer activity of anti-angiogenic drugs, we analyzed the contrast enhancement of xenografted tumors in mice treated with bevacizumab. Methods and Materials: Thirty nude mice were subcutaneously implanted with human osteosarcoma. After, 2 weeks, mice were allocated into 2 groups (n = 10) and bevacizumab or saline treatment was initiated (i.p. Г—4 at 3-day interval). CEUS with a microbubble agent, Sonazoid, was performed before and 2, 6, 9 and 13 days after initiation of the treatment. Intratumoral perfusion areas were quantified by binarizing the grayscale images. Intratumoral microvessels were observed by CD31 immunohistochemistry at 14 days. The tumor size, intratumoral perfusion area and its ratio were compared between the groups at each time point by t-test. Results: Tumor growth was slower in the bevacizumab group, but the difference did not reach statistical significance. Contrast enhancement in the tumors visually decreased from 6 days in the bevacizumab group, while strong enhancement remained in the control group. The perfusion area increased only in the control group and was significant at 9 and 13 days (P = 0.0073 and P = 0.0108). The ratio of the perfusion area decreased in the bevacizumab group, while it increased in the control group and was significant at 9 and 13 days (P = 0.0005 and P = 0.001). Intratumoral microvessels were obviously fewer in the bevacizumab group than in the control group. A B C D E F G H S147 Friday Purpose: To determine the optimum imaging delay for the detection of colorectal hepatic metastases using Gd-EOB-DTPA (PrimovistВ®) by measuring lesion contrast-to-noise ratio (CNR), liver signal-to-noise ratio (SNR) and diagnostic performance using T1-weighted imaging at dynamic imaging, 20 min, 1 hour and 4 hours post contrast. Methods and Materials: A total of 20 patients with colorectal metastases underwent MR imaging before and after (breath-hold T1-weighted imaging dynamically at 20 min, 1 hour and 4 hours) PrimovistВ® administration. Four image sets (unenhanced T1 and T2-weighted images, together with one of four post-contrast T1-weighted) were independently reviewed by two experienced radiologists in consensus. The likelihood of malignancy was scored on a five-point scale and results compared by ROC analysis. The gold standard was pathology and follow-up imaging. For each post-contrast T1-weighted study, lesion CNR and liver SNR were computed from ROI drawn around metastases, parenchyma and air. Results were compared using t-test. Results: A total of 87 metastases and 13 benign lesions were found. Imaging at 1 hour post-contrast (S1hr) resulted in the highest diagnostic accuracy (Az = 0.82) compared with Sdyn (Az = 0.70), S20 min (Az = 0.78) or S4hrs (Az = 0.69). However, the difference was not statistically significant (P 0.05, variance z-test). CNR was higher at 1 hour (mean 250) compared to 20 min (mean 213; P = 0.004) or 4 hours (mean 158; P = 0.001). There was no significant difference in SNR at 20 min or 1 hour (P = 0.31), but both were significantly higher than at 4 hours (mean 414; P 0.01). Conclusion: The highest lesion CNR and diagnostic accuracy for detecting colorectal metastasis were achieved using T1-weighted imaging at 1 hour post-contrast, which may reflect lesion contrast washout. Methods and Materials: A total of 30 consecutive patients, 20 with unresectable HCCs and 10 with metastatic liver disease underwent TACE or precision TACE. For each superselective angiography CEUS was performed after injecting 0.5 ml of Sonovue (Bracco) in the microcatheter. For all patients, the aim was to thoroughly embolize the segments harboring the pathologic tissue. The ability of CEUS to predict the treated area was evaluated. The grade of vascularity at CEUS was correlated to the treatment outcome in terms of lipiodol uptake or necrosis. Results: In all cases, the enhancing area after CEUS strictly correlated with the treated area at CT control after 24 hours, and at CEUS demonstrated a faintly lipiodol uptake and no significant response after precision TACE. All hypervascular lesions showed a good early response to treatment in terms of lipiodol uptake and necrosis, while three cases with hypovascular HCCs and two cases with hypovascular metastases showed reduced or no response. In 9 cases, CEUS changed the strategy of treatment and in 11 increased the operator confidence. Conclusion: CEUS with intraarterial injection of US contrast media can be a valid tool for increasing the precision of endovascular liver-directed therapies and can increase the efficacy and safety profile by sparing normal liver parenchyma. The major limit is the reduced visibility of deep-seated lesions. Scientific Sessions Conclusion: CEUS has potential for early prediction of the anticancer activity of bevacizumab by visualizing intratumoral perfusion depressions that reflect its anti-angiogenic effects. B-028 11:33 Contrast-enhanced ultrasound in comparison to color duplex ultrasound and multislice computed tomography (MS-CT) angiography in the detection of endoleak following endovascular aneurysm repair D.-A. Clevert, S. Weckbach; Munich/DE ([email protected]) Purpose: The purpose of this study was to compare color duplex ultrasound (CDU), contrast-enhanced ultrasound (CEUS) and multislice computed tomography (MSCT) angiography in the routine follow-up of patients following endovascular repair (EVAR) of abdominal aortic aneurysm (AAA). Methods and Materials: A total of 129 consecutive patients with AAA underwent endovascular aneurysm repair and were imaged with CDU, CEUS and MS-CT angiography at regular intervals after the procedure. Each imaging modality was evaluated for the detection of endoleaks. The presence of endoleaks was analyzed and the conspicuity of findings assessed. Results: CTA was used as the gold standard in determining the presence of endoleaks. CDU was true positive for endoleaks in 17/129 patients (13.2%) and false positive for endoleaks in 6/129 patients (4.6%). The sensitivity of CDU was therefore 32.3% and its specificity 92.8%; the positive and negative predictive values were 0.71 and 0.72, respectively. CEUS was true positive for the detection of endoleaks in 45/129 patients (34.9%) and false positive in 6/129 patients (4.6%). The sensitivity of CEUS was therefore 100% and its specificity 93%; the positive and negative predictive values were 0.88 and 1. In the follow-up, the six false-positive endoleaks in CEUS were confirmed as true-positive endoleaks by CEUS and MS-CT. Conclusion: In the patient group, CEUS seemed to be more accurate in demonstrating endoleaks after EVAR than MS-CT angiography and may be considered as a primary surveillance modality, whereas CDU alone is not as sensitive as CEUS and MS-CT angiography in the detection of endoleaks. B-029 11:42 Image quality of multidetector CT coronary angiography using high iodine concentration contrast material: Comparison of iopromide 370 versus iomeprol 400 Y. Choe, D. Ye; Seoul/KR ([email protected]) Purpose: To compare the image quality of coronary CT angiography (CCTA) between the group with iopromide 370 and those with iomeprol 400. Methods and Materials: In this prospective study, CCTA was performed in 130 enrolled patients using a 64-slice MDCT (Toshiba, Aquilion). Patients were randomized to 2 groups (65 patients for each group). 70 mL of iopromide 370 (Group A; Ultravist 370) or 70 mL of iomeprol 400 (group B; Iomeron 400) was injected at 4 mL/sec for CCTA. The degree of CT attenuation was measured in 6 locations of coronary arteries and 4 locations of aorta using ROI. Curved planar reconstruction and volume-rendered images of 13 coronary artery segments were evaluated by 2 readers in consensus. For each segment, image quality was graded in a 4-point scale with 1 for excellent enhancement. Results: The attenuation values in coronary arteries and aorta were similar between two groups without statistical significance. Mean attenuation values in coronary arteries in groups A and B were 452.7 p 92.7 HU and 459.9 p 88.7 HU (P = 0.71), respectively. Mean attenuation values in the aorta in groups A and B were 437.4 p 82.5 HU and 444.6 p 84.0 HU (P = 0.33), respectively. Mean image quality score of 13 coronary artery segments in groups A and B was 1.13 p 0.33 and 1.18 p 0.41, respectively. There was no significant difference in image quality score of each coronary segment in two groups. Conclusion: The image quality of CCTA using iopromide 370 or iomeprol 400 is equally excellent. B-030 11:51 Influence of body weight, body mass index and heart rate on coronary attenuation in dual-source coronary CT-angiography K. Anders, U. Baum, S. Achenbach, D. Ropers, A. Renz, W.A. Bautz; Erlangen/DE ([email protected]) Purpose: An inverse correlation between body weight (BW) and vascular attenuation is known for abdominal vessels. Does early contrast in coronary CT-angiography (corCTA) obey the same rules? In this study, attenuation in corCTA with a scantimebased injection protocol was correlated with BW, body bass index (BMI) and heart rate (HR) as well as individual start delay (iSD) as indirect circulation marker. S148 A B C D E F G F H Methods and Materials: 200 consecutive corCTA datasets with a scantime-based injection protocol (amount of contrast = scantime x 5 ml + 5 ml; transit time determined by testbolus) were used for retrospective analysis. ROI measurement was performed in the proximal coronaries. The calculated mean of those 4 measurements was correlated with BW, BMI, HR and iSD. Results: 183 datasets were available for correlation. Mean amount of contrast used was 60 ml. Mean attenuation was 382 Hounsfield units (HU). For all 183 patients, correlation coefficients were -0.59, -0.40, -0.19 and 0.03 for HU vs. BW, BMI, HR and iSD, respectively. Subgroup analysis according to the amount of contrast (50, 55, 60, 65 and 70 ml) yielded the following correlation: -0.71, -0.65, -0.74, -0.14 and -0.37 for BW, -0.51, -0.57, -0.54, 0.37 and -0.14 for BMI, -0.23, -0.39, -0.12, -0.07 and 0.08 for HR, 0.23, -0.06, -0.07, -0.64 and 0.16 for iSD. Conclusion: Even though corCTA is performed during cardiac “first-pass”, correlation between BW/BMI vs. coronary attenuation still exists. It is comparable to recently published data for the pulmonary arteries (r=-0.26 to -0.48). Correlation with indirect circulation markers remains inconclusive. 10:30 - 12:00 Room F1 Genitourinary SS 207 Uterus and ovaries: MDCT and MR studies Moderators: M. Bekiesinska-Figatowska; Warsaw/PL G. Ivanac; Zagreb/HR B-031 10:30 Role of a 3D T2-weighted turbo-spin-echo sequence (VISTA) for assessment of pelvic deep endometriosis: Initial clinical experience at 3 T C. Roy, A. Matau, G. Bierry, A. Youssef, A. Wattiez; Strasbourg/FR ([email protected]) Purpose: To prospectively assess the value of a 3D T2wTSE (VISTA) sequence by comparison with a standard set of 2D T2wTSE to evaluate pelvic deep endometriosis. Methods and Materials: A total of 34 women having severe endometriosis underwent MR at 3.0 T (Achieva, Philips) before surgery of the nodule with a standard set of three orientations T2wTSE (TR/TE : 4,262 ms/80 ms, 0.6 x 0.7 x 3.5 mm3), 3:12 min and with a 3D T2w VISTA (TR/TE/FA : 2,113/200/120, 0.9 x 0.9 x 1.1 mm3, 4 : 58 min) with pelvic coil. SNR from fat, urine, nodule and nodule-fat CNR were measured from ROI. Two independent radiologists correlated 3D TSE VISTA with 2D TSE and rated the image quality with the contrast impression of nodule/surrounding tissue, signal homogeneity and artefacts. Results: Nodule SNR was lower with VISTA (258 p 11) than with 2D TSE (589p 15). Urine, fat SNR and nodule-fat CNR were higher with 3D VISTA (1,527, 1,237, 985 p 11) than with 2D TSE (1,443, 1,197, 589 p 15), respectively. Image quality, CNR and signal homogeneity of transverse, coronal and oblique orientations were rated significantly higher for 3D VISTA than for 2D TSE; but lower for sagittal (P 0.05). Minor flow artefacts did not alter diagnosis. Use of interactive 3D MPR software for VISTA 3D data sets providing multiplanar views improvement was considered as essential for the diagnostic confidence of pelvic structures involvement. Conclusion: At 3 T, unique 3D VISTA sequence with multiplanar high quality images and contrast provides accurate evaluation of severe deep endometriosis. It makes multiple 2D acquisitions unnecessary. B-032 10:39 Role of MDCT in identification of the bleeding site causing postpartum bleeding or bleeding after dilatation and curettage: A comparison with angiography N. Lee, J. Yeom, S. Kim, C. Kim, J. Lee, U. Jeon, D. Suh; Busan/KR Purpose: To retrospectively evaluate accuracy of MDCT for identification of the bleeding site causing postpartum bleeding or bleeding after dilatation and curettage. Methods and Materials: Ethics committee approval and informed consent were obtained. Thirty consecutive patients (mean age, 31.1 years; range, 24-39 years) with postpartum bleeding or bleeding after dilatation and curettage underwent MDCT prior to embolization. Two radiologists compared CT findings with those of conventional angiography in consensus. Conventional angiography was used as the standard of reference. Active bleeding on CT was defined as extravasation of contrast material at contrast-enhanced CT. Presence of contrast extravasation in Scientific Sessions B-033 10:48 Modification of signal intensities of tumor and normal myometrium after USPIO administration in patients with uterine malignancies: A quantitative retrospective study on a large patient population P. Paolantonio, R. Ferrari, M. Rengo, F. Vecchietti, P. Lucchesi, D. Caruso, A. Laghi; Latina/IT ([email protected]) Purpose: To quantitatively evaluate the signal intensity modification of the myometrtium and uterine tumor after USPIO administration. Methods and Materials: We retrospectively evaluated a patient population of 88 females, affected by uterine neoplasm, who were previously enrolled in a multicentric study on lynpho-specific properties of USPIO. For each patient, GRE T2*W sequences acquired before and 24 hours after iv administration of 2.6 mg/kg body weight of Sinerem (Guerbet, Paris, France) were available. Image analysis was performed by two radiologists in consensus and included quantitative analysis of signal intensity (SI) of both normal myometrium and neoplastic lesions before and after USPIO administration. S/N and C/N were calculated. Quantitative data were compared using Wilcoxon test (P 0.05). Results: Quantitative analysis showed a statistically significant difference between SI of the myometrium on plain-MRI and USPIO-enhanced-MRI with a mean SNR difference of 16.1. Also, the tumor showed a significant reduction of SNR after USPIO administration that was less strong compared to the myometrium SNR drop (mean difference of 9.8). Therefore, C/N between the tumor and normal myometrium significantly increased following USPIO administration. Conclusion: Intravenous injection of USPIO provides a decrease of SI of both the normal myometrium and tumor; negative enhancement of the myometrium was much more evident for the myometrium compared to the tumor, leading to higher tumor conspicuity. Further studies are necessary to assess the mechanism of those effects. B-034 10:57 Epithelial and stromal metabolite changes in the transition from cervical intraepithelial neoplasia to cervical cancer: An in vivo 1H magnetic resonance spectroscopic imaging study with ex vivo correlation S.S. De Silva1, G.S. Payne1, V.A. Morgan1, T.E.J. Ind2, J.H. Shepherd2, D.P.J. Barton2, N.M. deSouza1; 1Sutton Surrey/UK, 2London/UK ([email protected]) Purpose: To establish the epithelial and stromal metabolite changes in pre-invasive and invasive cervical cancer in vivo and correlate findings with magic angle spinning (MAS) MR spectroscopy of tissue samples. Methods and Materials: Forty-seven women (19 with cervical intraepithelial neoplasia [CIN], and 28 with cervical cancer) underwent endovaginal MR imaging at 1.5 T with T2-W scans in 3 orthogonal planes to the cervix and localized 2-D MR spectroscopy (PRESS technique, TR 1500 ms, TE 135 ms). Peaks from tCho, 2 ppm and triglyceride-CH2 were measured in epithelial ( 50% epithelium, no tumour), stromal ( 50% stroma, no tumour) and tumour ( 30% tumour) voxels. The unsuppressed water signal from the corresponding voxel was used as an internal standard. Results: Analysable data was obtained from 17 CIN and 25 cancer patients. A significant increase in tCho (p=0.03) and 2 ppm (p=0.007) was observed in tumour voxels compared to epithelial voxels from pre-invasive patients but not compared to epithelial voxels from patients with invasive cancer. There was a tendency to higher tCho, 2 and 1.3 ppm triglycerides in stroma from cancer compared to CIN patients, but these differences were not significant. Differences in 1.3 ppm -CH2 triglycerides were not significant between groups. There was no correlation between tCho and -CH2 triglycerides in vivo and ex vivo. Conclusion: Estimated concentrations of tCho and 2 ppm resonances increase in both tumour and adjacent epithelium in progression from pre-invasive to invasive cervical cancer. B-035 11:06 Contrast-enhanced dynamic magnetic resonance imaging as a predictor of radiosensitivity in cervical cancer K.L. Szluha1, K. Lazanyi1, Z. Adamecz1, R. Poka1, J. Toth1, C. Andras1, A. Horvath1, A. Abramyuk2, N. Abolmaali2; 1Debrecen/HU, 2Dresden/DE ([email protected], [email protected]) Purpose: The aim of this study was to measure radiotherapy-induced changes in cervical cancer by means of contrast-enhanced dynamic magnetic resonance imaging (DCE-MRI). Methods and Materials: Ten patients with T2a cervical cancer were examined with DCE-MRI before and after 3 x 6 Gy intracavitary high-dose rate radiotherapy (HDRRT). DCE-MRI utilized dynamic T1-weighted imaging during intravenous Gd-DTPA administration. After HDRRT, all patients underwent Wertheim-Meigs operation. The DCE-MRI were analyzed by signal intensity ratio (SIR) and, a new indicator, ratio of signal intensity changes in time (RISI) applied to cervical cancer tissue and healthy uterus, muscle and fat as reference. Results of SIR and RISI were compared with both pathological findings after Wertheim-Meigs operation and clinical response. Results: SIR and RISI averages of cervical cancer (89.06% and 15.36/sec) and of healthy uterine tissues showed significant differences before and after HDRRT, especially during the first pass (30 seconds). Both intratumoral enhancement differences and individual changes after radiotherapy were characteristic. SIR and RISI levels were higher than 90% and 9.5/sec, respectively, and decreased more in well-responding patients. A tumor activity decrease was predicted by DCE-MRI only in cervical cancers where SIR and RISI decreases exceeded 40% after HDRRT. With the latter patients, better disease-free survival (DFS) and local control (LC) rates were observed. Conclusion: In a preoperative evaluation comparative study, intra and interpatient variability of contrast enhancement in DCE-MRI was assessed. DCE-MRI provides important information about individual tumor activity in cervical cancer and its changes after radiotherapy, which may be helpful for follow-up and tumor response prediction. B-036 11:15 Evaluation of necrosis with DCE-MRI subtracted imaging as a predictor of cervical cancer response to chemo-radiotherapy L. Mannelli, E. Sala, A. Priest, L. Zhi-Yong, M. Zahra, D.J. Lomas; Cambridge/UK ([email protected]) Purpose: To retrospectively evaluate dynamic contrast enhanced magnetic resonance (DCE-MRI) subtracted imaging as predictor of chemoradiotherapy response in patients with advanced cervical cancer. Methods and Materials: 13 patients with advanced cervical cancer treated with chemo-radiotherapy underwent DCE-MRI at 3 time-points: before treatment, after 2 weeks of chemoradiotherapy and at the completion of chemoradiotherapy (5 weeks) but before the start of brachytherapy. The MRI protocol included T1W axial and T2W sagittal, axial and axial oblique images followed by a T1W perfusion sequence (PWI). This consisted of a 3D T1W fast spoiled gradient echo (TR/TE = 4.8/1.5 ms, flip angle = 18o) of 4 contiguous sagittal sections repeated every 3 seconds for a total of 180 seconds after contrast administration. Subtraction imaging was performed at 18, 78 and 138 seconds after contrast medium injection using GE-AW 4.2_03 Image Combination (Version 3.0.63) subtraction tool based on a voxel-by-voxel method. The percentage of tumour necrosis was assessed on subtracted images using a visual analogous scale and was correlated with radiological tumour response. Results: 13 patients had a total of 38 MRI examinations. The pre-treatment percentage tumour necrosis assessed using arterial subtraction imaging (at 18 seconds) showed an excellent inverse correlation with percentage of tumour regression (r = -0.934, p 0.001). There was an excellent agreement between the two readers (Cronbach's Alpha = 0.961). Conclusion: This study shows that pre-treatment tumour necrosis assessed with arterial image subtraction predicts the radiation response in cervix cancer. This measurement may allow a tailored therapy for patients with cervix cancer. A B C D E F G H S149 Friday each anatomic location was recorded (left and right uterus, left and right cervix, left and right vagina, left and right paravaginal or parauterine region, and left and right rectus muscle). Sensitivity, specificity, positive and negative predictive values, and accuracy of MDCT for detection of bleeding were assessed. We also assessed the presence of additional abnormalities on CT that could influence the decision of further treatment or diagnostic evaluation. Results: MDCT depicted contrast extravasation in 27 of 30 patients. Overall location-based sensitivity, specificity, accuracy, and positive and negative predictive values of MDCT for detection of bleeding were 92% (46 of 50), 96% (240 of 250), 95% (286 of 300), 82% (46 of 56), and 98% (240 of 244), respectively. MDCT also found additional abnormalities in 10 of 30 patients. Conclusion: CT may be useful in the demonstration of the anatomic location of a significant arterial hemorrhage as sites of intravenous contrast material extravasation. Scientific Sessions B-037 11:24 Can quantitative dynamic contrast enhanced MR imaging (DCE-MRI) be used to accurately characterize complex adnexal masses? P. Dilks, P. Narayanan, A. Sahdev, R.H. Reznek, A. Rockall; London/UK ([email protected]) Purpose: To evaluate and compare the accuracy of quantitative DCE-MRI with qualitative visual assessment in the characterization of complex adnexal masses. Methods and Materials: MR imaging of 26 patients (age 17-80 years, mean 43 years) with a complex adnexal mass, presenting over a 24-month period, was retrospectively reviewed and correlated with histology following resection. These were categorised into benign (N = 14) and malignant (N = 12) groups. A total of 55 cases without either a solid tumour component, histology or dynamic imaging were excluded. A 1.5 T unit was used to obtain T1, T2, fat suppressed T1 weighted images and a 5-point dynamic series between 0 and 150 ms post-gadolinium administration (rate of 3 ml/s). Regions of interest (ROI’s) were drawn around the solid tumour component and control ROI’s were drawn over muscle and myometrium. Maximum early enhancement (MEE) and maximum relative enhancement (MRE) parameters were compared between the groups in addition to a blinded visual assessment of enhancement. Results: There was no significant difference in tumour size or control ROI enhancement between the groups. The MEE (p 0.001) and MRE (p 0.05) were significantly different between benign and malignant lesions. ROC analysis with a cut off point of 250 for MEE gave a sensitivity of 100%, specificity of 92.8%, PPV of 92.3%, NPV of 100% and accuracy of 96.2% for mass characterisation. Visual scoring gave a sensitivity of 75%, specificity of 85.7% and accuracy of 80.7%. Conclusion: Quantitative DCE-MRI can confidently predict malignancy in complex solid/cystic adnexal masses with greater accuracy than qualitative visual assessment. B-038 11:33 Imaging modalities for preoperative staging ovarian cancer: Comparison between multidetector CT (MDCT) and MRI using diffusion-weighted sequences with background body signal suppression (DWMRI) Y. Badachi, J.-P. Akakpo, D. Grenier, E. Vincent, J.-P. Lefranc, P.A. Grenier, O. Lucidarme; Paris/FR ([email protected]) Purpose: DWMRI is emerging as a new promising technique in imaging peritoneal metastases. Our objective was to compare DWMRI to MDCT and surgical laparotomy in the preoperative assessment of ovarian cancers. Methods and Materials: To date, preoperative MDCT and DWMRI (T1w, T2w and DWIBS sequences) covering abdomen and pelvis of 15 patients were separately reviewed by 2 independent observers asked to stage (Figo) the cancer and to predict non-optimal resection. Criteria of non-resectability were retroperitoneal presacral disease, lymph node enlargement above renal hilum, abdominal wall invasion, liver metastases, implants of 2 cm on diaphragm, lesser sac, porta hepatis, intersegmental fissure, gall bladder fossa; gastrosplenic, gastrohepatic ligament and small bowel mesentery. Stage and resectability obtained with MDCT, DWMRI were compared to the result of surgical laparotomy. Results: For both observers, correct staging of the disease was achieved in 12 out of 15 patients with MDCT (1 overestimation, 2 underestimations) and with DWMRI (2 overestimations, 1 underestimation). For both observers resectability was correctly predicted by MDCT and DWMRI in 7 out of 7 (100%) patients. For observer 1 non-optimal resectable disease was correctly predicted by MDCT and DWMRI in, respectively, 6 out of 8 and 7 out of 8 patients and for observer 2 in, respectively, 5 out of 8 and 6 out of 8 patients. By averaging the observers, sensitivity for suboptimal debulking were 68.7% for CT and 81.2% for DWMRI without significant difference. The DWI sequence clearly helped the observers to depict diaphragm and porta hepatis involvement. Conclusion: DWMRI has at least a comparable sensitivity than MDCT to preoperatively stage ovarian cancer and to predict suboptimal debulking. B-039 11:42 Combined high-resolution pelvic and whole-body sliding multislice MRI for ovarian cancer staging: Comparison with MSCT G. Pache, T. Baumann, A.-O. Schaefer, M. Langer; Freiburg/DE ([email protected]) Purpose: Comparison of combined high-resolution pelvic MRI and whole-body sliding multislice (SMS), a novel MRI technique for axial moving table acquisitions, with MSCT for staging of ovarian cancer patients. Methods and Materials: A total of 20 patients with ovarian cancer underwent CT and MRI examinations within a median interval of 3 days. The MR imaging protocol (1.5 T) consisted of triplanar T2-weighted high resolution images of the pelvis and S150 A B C D E F G F H a whole-body axial TIRM and contrast enhanced FLASH-2D sequence in SMS technique. Laparotomy and histopathology were used as the standard of reference. CT and MRI images were independently randomized. Two radiologists evaluated all detectable intra- and extrapelvic disease manifestations in both modalities. Results: Concerning peritoneal spread MRI was superior in detecting diaphragmal and liver surface lesions with 89% (8/9) and 92% (12/13) compared to 67% (6/9) and 69% (9/13) for MSCT. MRI showed one false positive diaphragmal lesion. MRI detected all cases of rectosigmoid infiltration (8/8), whereas MSCT had two false negative findings. MRI could correctly rule out bladder and rectosigmoid infiltration that had been suspected by MSCT in two cases. No cases of hepatic spread or direct hepatic infiltration as well as enlarged abdominal or supradiaphragmal lymph nodes were missed by either method. Conclusion: Combination of high-resolution pelvic MRI and whole-body SMS MRI was superior to CT for staging of local tumor extent and showed excellent detection of peritoneal or metastatic spread from ovarian cancer. Consequently, this imaging strategy raises the possibility of a one-stop staging regimen for ovarian cancer patients with MRI. B-040 11:51 Diffusion-weighted MR (DWI-MR) imaging in the assessment of tumour grade in endometrial cancer N. Bharwani, P. Narayanan, A. Sahdev, R.H. Reznek, A.G. Rockall; London/UK Purpose: To determine if there is a correlation between tumour grade and apparent diffusion coefficient (ADC) in endometrial cancer. Methods and Materials: A total of 15 patients with endometrial cancer underwent DWI-MR imaging (Philips Achieva 1.5 T system, torso phased array coil) using six b-values (50, 100, 150, 250, 500, 750). ADC maps were produced and the tumour ADC values were correlated with histological tumour grade obtained at hysterectomy (14 patients) or endometrial biopsy (1 patient). MRI images were independently reviewed by two experienced readers and intra- and inter-observer variability documented. Results: The mean ADC value (10-3 mm2/s) of grade 1 (n = 6), 2 (n = 2) and 3 (n = 3) tumours was 0.85 (SD 0.06), 0.94 (SD 0.002) and 0.79 (SD 0.08), respectively. Using linear regression analysis, a good correlation (R = 0.60) was obtained between tumour grade and ADC value. There was a significant difference (P 0.05) between ADC values of grade 1 and grade 3 tumours. No significant difference was seen between ADC measurements for grade 1 versus 2 and grade 2 versus 3 tumours. One patient had benign endometrial hyperplasia and the endometrial ADC value was 1.45. Conclusion: High tumour grade is an adverse prognostic factor in endometrial cancer. This study is ongoing, but preliminary data suggest a good correlation between ADC values and histological grade. Potentially this information, taken in conjunction with a biopsy, may improve pre-operative prognostication and thereby optimise patient management. 10:30 - 12:00 Room F2 Breast SS 202 New developments on digital systems in breast diagnosis Moderators: P. Alonso-BartolomГ©; Santander/ES H. Bosmans; Leuven/BE B-041 10:30 Breast tomosynthesis: Assessment of breast cancer size compared with digital mammography and ultrasonography D.B.R. FГ¶rnvik, S. Zackrisson, P. Timberg, T. Svahn, S. Mattsson, A. Tingberg, I. Andersson; MalmГ¶/SE ([email protected]) Purpose: Mammographic tumor size measurement is difficult because breast structures are superimposed onto a two-dimensional (2D) plane, potentially obscuring the tumor outline. Breast tomosynthesis (BT) is a 3D X-ray imaging technique in which low-dose images are acquired under rotation of the X-ray tube through a limited angle at a total dose comparable to digital mammography (DM). These low-dose images are used to mathematically reconstruct a 3D image volume of the breast, thus reducing the problem of superimposed tissue. The aim of this project was to investigate whether breast cancer size can be more accurately assessed with BT compared with DM and ultrasonography (US). Scientific Sessions B-042 10:39 Clinical performance of digital breast tomosynthesis compared to digital mammography: Blinded multireader study G. Gennaro1, A. Toledano2, E. Baldan1, C. di Maggio1, M. La Grassa1, I. Polico1, A. Proietti1, A. Toffoli1, L. Pescarini1; 1Padua/IT, 2Toronto, ON/CA ([email protected]) Purpose: To evaluate potential differences in clinical performance between digital breast tomosynthesis (DBT) and digital mammography (FFDM). Methods and Materials: 200 consenting women with breast lesions classified as doubtful or suspicious at mammography and/or ultrasound were enrolled in the study. They underwent digital mammography (CC, MLO) and tomosynthesis (MLO only) on both breasts. The DBT prototype was an investigational equipment based on a standard FFDM unit (Senographe DS, GE Healthcare), modified to acquire multiple projections over a limited arc. DBT dose levels were kept equivalent to those delivered for standard mammography examinations. Six experienced radiologists reviewed independently left and right breasts of each patient with no access to any clinical information. FFDM and DBT images of each breast were reviewed in separate reading sessions; findings were identified, localized and rated according to the ACR BIRADS scale. Clinical assessments from each radiologist were compared with the truth and multiple-reader-multiple-case (MRMC) ROC analysis was applied to a dataset of 371 breasts. This analysis summarizes areas under ROC curves (AUCs) across radiologists for FFDM and DBT, and compares the results. Results: AUCs for detecting breasts with malignant lesions were 0.884 (DBT) versus 0.852 (FFDM). The 95% confidence interval (CI) for the difference lies entirely above a delta=0.05 non-inferiority margin (-0.03 to 0.09; p=0.285). Similar results were obtained when breasts with benign lesions were also considered positive: 0.857 (DBT) versus 0.845 (FFDM), 95% CI for difference -0.03 to 0.05 (p=0.562). Conclusion: In the study population, tomosynthesis (MLO) showed non-inferiority versus two-view digital mammography. B-043 10:48 Breast tomosynthesis reduces radiologist performance variability compared to digital mammography A. Smith1, E. Rafferty2, L. Niklason1; 1Bedford, MA/US, 2Boston, MA/US ([email protected]) Purpose: To study radiologist variability when using breast tomosynthesis in conjunction with digital mammography. Methods and Materials: 1000 patients were imaged using digital mammography (2D) and breast tomosynthesis (3D). Cases included normals, recalls, benign biopsies, and cancers. 310 cases were selected for two reader studies, totaling 27 radiologists. The breast radiologists lacked clinical experience with tomosynthesis and were trained in a 2-day session. They then read the cases, first 2D, and then evaluated the 2D+3D images. Evaluations used BIRADS and probability of malignancy metrics. Performance was measured using receiver operating characteristics (ROC) curves, and recall rates for screening cases. Their performance variability in area under the ROC curve (AUROC) and recall rates was studied separately for 2D and 2D+3D. This analysis was performed for all images, and subsets involving masses and calcifications. Results: For all cases, the variability, or standard deviation, of AUROC for the radiologists was 70% using 2D+3D compared to 2D alone. For pathologies containing masses, the standard deviation of the AUROC for 2D+3D was even smaller - 50% of the variation using 2D. The variability of AUROC for calcifications was equivalent for 2D+3D compared to 2D. With recall rates for screening cases, the variability in recall rates using 2D+3D was 50% of the variability using 2D. Conclusion: Tomosynthesis has previously shown to improve radiologist performance. This study shows that the variability of performance is also reduced when using tomosynthesis. This can be interpreted to mean that the use of tomosynthesis gives radiologists improved confidence in their evaluations. B-044 10:57 Clinical relevance of the standardised update value (SUV) in staging breast cancer with FDG-PET/CT A. Zytoon1, M. El-Kholy1, K. Murakami2, O. Ebied1; 1Menoufiya/EG, 2Tochigi/EG ([email protected]) Purpose: FDG-PET/CT with standardized uptake value (SUV) estimation was applied to breast cancer patients for the purpose of preoperative evaluation of the extent of the disease. Methods and Materials: FDG-PET/CT was performed preoperatively in 71 patients with breast cancer, and the maximum standardized uptake value (SUVmax) of tumors, as well as combination of SUVmax and tumor marker CA 15-3 were investigated for a significant association with lymph node spread and distant metastasis. Results: Tumor SUVmax high ( 3.1) was found to have a reliable predictive value for lymph node spread (sensitivity 82.9%, specificity 75%, P 3.8)/CA. 15-3-Elevated was found to be superior for the prediction of metastasis (sensitivity; 75%, specificity; 92.7%, P = 0.0001). Moreover, linear regression analysis identified the best correlation was between SUVmax-High ( 3.1) with lymph node spread {correlation coefficient (r2) = 0.580, P = 0.0001}, and SUVmax-High ( 3.8)/CA 15-3-Elevated with distant metastasis {correlation coefficient (r2) = 0.677, P 0.0001}. Conclusion: SUVmax is a reliable predictor of lymph node spread, and if combined with tumor marker assay (CA 15-3) labeled SUVmax-High/CA 15-3-Elevated is sufficient for the early detection of breast cancer metastasis. This outcome suggests that the FDG-PET/CT findings with SUV calculation could have a strong positive impact on breast cancer patients. B-045 11:06 Digital breast tomosynthesis (DBT) versus full field digital mammography (FFDM): Comparison of a system performance using a contrast detail phantom A. Nitrosi, G. Borasi, M. Bertolini, F. Nicoli, A. Botti; Reggio Emilia/IT ([email protected]) Purpose: To evaluate the difference in performances of a 2D planar digital mammographic system versus tomosynthesis. Methods and Materials: A contrast detail phantom was obtained embedding a plexyglass layer including holes of different diameter (from 4.3 to 0.18 mm) and depth (from 0.85 to 0.41 mm) between layers containing a breast simulating material. The tomosynthesis system we tested (Hologic) uses a direct detection, 70 Вµm pixel, 24x30 cm detector. The acquisition protocol included 15 low dose projections over a p7.5В° angular range and an additional 2D planar view. The projections' data are reconstructed using a filtered back projection algorithm to give 1 mm-thick slices. The average glandular dose for the tomosynthesis acquisition was of 1.45 and 1.25 mGy for the planar view. Images were repeated replacing the breast tissue with an equivalent thickness of PMMA. To obtain different realizations of the non-stochastic noise for each acquisition the details sheet was rotated. To average the pixel partial volume effect each acquisition was repeated in slightly different phantom positions. Using an automatic software analysis tool, the contrast to noise ratio (CNR) of each detail was evaluated. Results: When the phantom was embedded in breast tissue, in the whole range of the hole size, the CNR of the tomosynthesis reconstructed images was about a factor two higher than in the planar mode (P=2E-5). Similar results were obtained with an equivalent thickness of PMMA (P=3E-4). Conclusion: In a breast simulating phantom, the tomosynthesis technique allowed highly significant improvement of CNR respect to the 2D image. B-046 11:15 Designing an anthropomorphic breast phantom for breast tomosynthesis S. Rouault, R. Klausz, S. Muller, R. Iordache, H. Souchay; Buc/FR Purpose: Phantoms for 2D mammography are unrealistic in many ways, and their usage for performance assessment or optimization of digital breast tomosynthesis (DBT) systems could be misleading. Their most prominent features usually include non-realistic local absorption coefficient, planar lesion inserts and absence of texture, all of which are critical to volumetric imaging of the breast. We propose a method to obtain anthropomorphic phantoms with adequate absorption, texture content and lesion-like objects, for a more realistic assessment of the threedimensional imaging performance. Methods and Materials: The variety of materials present in the breast was initially mimicked by a careful choice of agar-agar-based gels for glandular and skin tissue, and animal fat for adipose tissue. The second step was to generate the proper texture in each region of the breast. This was obtained by assembling each texture A B C D E F G H S151 Friday Methods and Materials: A prototype, research BT system was used. The inclusion criterion for BT examination was women with subtle, but suspicious, findings of breast cancer selected from digital screening mammography or symptomatic women with subtle or negative findings on DM, but with suspicious lesions on US. A total of 65 women with 76 breast cancers were included. BT, DM and US sizes were measured independently by experienced radiologists without the knowledge of pathology results, which were used as reference. Scatter plots and linear regression were generated to produce predictive R2 statistics. Results: The tumor outline could be determined in significantly more cases with BT (84%) and US (83%) than with DM (51%). BT had the highest size correlation with pathology (R2 = 0.66), compared to US (R2 = 0.49) and DM (R2 = 0.47). Conclusion: The study indicates that BT is superior to DM and US for the estimation of breast tumor size. Scientific Sessions inside nested moulds at moderate heat. Microcalcification clusters were made of egg-shell decanted in agar-agar inserts, and injected into the texture, together with opacities of various shapes. Scoring methods were developed to procure discriminating imaging performance. Results: The phantom polymerizes under refrigeration, and remains stable at ambient temperature over weeks. The range of absorption coefficients attainable is 0.8-1.2 g/cm3, yielding realistic local absorption properties in the phantom, that are key for DBT performance assessment. The texture typology is adjustable, covering all BIRADS densities. Conclusion: A method for creating phantoms that mimic real breast architecture characteristics was found, that can be used for the optimization of acquisition sequence in DBT. B-047 11:24 Computed tomographic laser mammography (CTLM) as an adjunct to mammography in dense breasts J. Qi; TianJin/CN ([email protected]) Purpose: To determine if CTLM can improve mammographic sensitivity in women with dense breast tissue. Methods and Materials: Breast density was evaluated by mammography in 155 women scheduled for biopsy or surgery and classified as “heterogeneously dense”, (BI-RADS Grade 3), or “extremely dense”, (BI-RADS Grade 4). CTLM was then performed on all patients with dense breasts. The sensitivity and specificity of mammography alone, (M.al), CTLM alone, (CT.al) and CTLM adjunct to mammography (M+CTLM) were assessed based on pathology findings. Results: Among 74 grade 3, and 81 grade 4 breasts, pathology revealed 79 malignant and 76 benign lesions. Angiogenesis was seen in 72.15% of malignant and 31.57% of benign lesions (C2=25.558, p = 0.000). In extremely dense breasts the sensitivity of M.al, versus M+CTLM was 34.40 vs 81.57%. (C2=13.071, p=0.000). The specificity of M.al versus M+CTLM was 90.48 vs 72.22%. (C2=4.386, p=0.072). In heterogeneously dense breasts the sensitivity of M.al versus M+CTLM was 68.29 vs 95.34% (C2=11.131, p=0.001). The specificity of M.al versus M+CTLM was 85.00 vs 55.26% (C2=8.288, p=0.004). The sensitivity of CTLM alone in extremely vs heterogeneously dense breasts was 74.40 vs 85.00% (C2=0.446, p=0.504) and specificity 71.00 vs 61.00%, (C2=0.000, p=1.000). Conclusion: Because CTLM, which detects angiogenesis, is not affected by breast density, its use as an adjunct to mammography could improve the present low sensitivity of mammography in dense breasts. B-048 11:33 Quantitative research of radiation dose comparison using clinical data on digital mammography C. Kohama1, A. Yoshida2, M. Matsumoto3, Y. Shidahiga4; 1Hatsukaichi/JP, 2 Miharashi/JP, 3Oosaka/JP, 4Fukuoka/JP ([email protected]) Purpose: We analyzed the relation between the radiation dose and the conditions (the focus, the filter and kV) using clinical mammography images and phantoms. Methods and Materials: Samples were 7,100 clinical images taken by GE Senograph DS with auto-mode (2006.5-2007.2). Conditions (the focus, the filter and kV) and the radiation dose were analyzed in respective breast thickness in terms of two modes, Contrast and Standard. Results: In the case of breast thickness of 2-4 cm, it was likely that Mo/Rh was selected on the auto mode both of Contrast and Standard used clinically normally. On the other hand, Rh/Rh was selected in the case of 5 cm or more. In comparison to dose-limiting value of EUREF (European Reference Organization for Quality Assured Breast Screening and Diagnostic Services), the dose was acceptable at any thickness on the standard mode. Conclusion: On FPDM both Mo/Rh and Rh/Rh were selected in the case of any thinner thickness. This result leads to prove our past research on FPD mammography and suitable spectrum, concluding that S/N ratio had not changed in the range of 2-6 cm of BR12 at the same value of average mammary gland dose. The thicker the thickness became, the more the radiation dose was measured on screen-film, but the radiation dose was decreased on FPDM. As this result corresponds with the past result (when Mo/Mo is more than 6 cm, Rh/Rh is better than Mo/Rh), it is supposed that the auto focus/filter was selected logically. S152 A B C D E F G F H B-049 11:42 Photon-counting single-shot dual energy breast tomosynthesis M. Lundqvist1, M. Г…slund1, M. Hemmendorff1, B. CederstrГ¶m2, M. Danielsson2; 1 Solna/SE, 2Stockholm/SE ([email protected]) Purpose: In mammography, there is room for improving sensitivity and specificity, and three-dimensional imaging has been proposed as an improvement to conventional projection mammography. A method for photon-counting single-shot dual energy breast tomosynthesis is presented and evaluated physically. Methods and Materials: Within the EU-funded HighRex-project, a tomosynthesis system based on a photon-counting scanning multi-slit technology from Sectra (Solna, Sweden) is being developed. The system features contrast-enhanced singleshot dual energy and optimisation of the photon-energy spectrum is performed with respect to both anatomical and statistical noise. In a 2D-environment a prototype is evaluated using an anatomical clutter phantom with iodinated contrast agent. Clinical trials have been initiated and a quality-control protocol is being evaluated. Results: Single-shot dual energy imaging provides short exposure times, which reduces the risk of artifacts in the reconstructed images. The boosted tomographic angle from using a rotational scan motion makes it possible to narrow the detector, which further reduces the exposure time down to approximately 2 seconds. The combination of the scatter rejection from the scanning geometry and the photoncounting technique providing a maintained DQE for the low-dose projection images results in an improved dose efficiency and image reconstruction. With a 40-45 kVp tungsten spectrum filtered with 2 mm aluminium, the smallest visible phantom contrasts were reduced by half with dual energy compared to conventional images. Conclusion: The single-shot photon-counting technique has the potential of providing artifact free images at very low doses. The contrast-enhanced dual energy increases the conspicuity of simulated lesions. B-050 11:51 Automated volumetric breast density assessment from digital mammography: Theory and validation K.W. Hartman1, J. Marshall1, A.P. Smith2; 1Santa Clara, CA/US, 2Bedford, MA/US ([email protected]) Purpose: To assess an automated algorithm that computes volumetric breast density from digital mammograms. Methods and Materials: An algorithm that computes breast density from digital mammograms (DM) was developed and evaluated. The algorithm does not require calibration markers or other objects in the mammogram, but rather uses known physics principles, technical equipment details, and compressed breast thickness for the calculations. It computes breast volume, fibroglandular tissue volume and percent glandularity. A number of clinical validations were performed: Comparisons were made between the algorithm output between left and right breasts; and comparisons between currents and priors. Finally, breast density in 2230 patients using both DM and breast MRI images were compared. Results: The Pearson correlation coefficient (PCC) was used to measure the correlation for the volume of fibroglandular tissue Vfg between currents and priors and had a value of 0.97. The PCC for Vfg between left and right breasts was 0.92. The PCC for Vfg between CC and MLO views was 0.93. The correlation coefficient for fibroglandular tissue volume between DM and MRI was 0.89. All the metrics studied showed that the algorithm provides internal consistency and reasonable correlation to the gold standard of segmenting MRI images to measure the volume of fibroglandular tissue. Conclusion: The automated algorithm provides self consistent methods of measuring volumetric breast density, when comparing CC to MLO and left and right breasts. Comparisons to breast density as measured by MRI also show good correlation. Scientific Sessions 10:30 - 12:00 Room G/H Head and Neck Nerves, teeth, eyes and ears Moderators: J. Qi; Tianjin/CN B. Verbist; Leiden/NL B-051 10:30 Trigeminal neuralgia due to neurovascular compression: Neural microstructural changes measured by high-resolution diffusion tensor imaging J. Lutz, J. Linn, J.H. Mehrkens, N. Thon, K. Seelos, H. BrГјckmann, M. Holtmannspoetter; Munich/DE ([email protected]) Purpose: The aim of the study was to preoperatively evaluate microstructural changes of the trigeminal nerves in patients with trigeminal neuralgia (TN), due to neurovascular compression, using a high-resolution diffusion tensor imaging sequence (DTI) and a 3D fast imaging employing steady-state acquisition sequence (3D FIESTA). Methods and Materials: A total of 20 patients with TN and evidence of a neurovascular contact were examined prior to surgical decompression using a 3.0 T MR scanner (Signa HDx, GE, USA) in combination with an eight-channel head coil. We used a single shot DTI EPI sequence along 15 different diffusion directions with a b-value of 1,000 s/mm2 and a slice thickness of 2 mm. Automated fiber tracking was used to evaluate fiber orientation. For anatomic correlation, a 0.6 mm isotropic 3D FIESTA sequence was acquired for coregistration with the functional DTI maps. The fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were studied. The DTI indices were correlated with surgical and clinical findings Results: FA was significantly (P 0.05) lower on the affected side (mean 0.3) compared to the contralateral side (mean 0.47). ADC was higher on the ipsilateral side compared with the contralateral side, but did not reach statistical significance. Detection of the trigeminal nerve was improved by the coregistration with the 3D FIESTA sequence. Conclusion: These findings suggest that DTI allows the identification of anisotropic changes between normal nerve tissue and affected trigeminal nerves. The coregistration of an anatomic 3D FIESTA and DTI is excellent for the delineation of the cisternal segments of the trigeminal nerves. B-052 10:39 Chronic facial pain: What contribution can MRI make? M. Tumen, N. Saeed, S.J. Golding; Oxford/UK ([email protected]) Purpose: Chronic facial pain is a debilitating condition and represents a diagnostic challenge. Clinical investigation includes excluding underlying disease, but incidence of lesions is perceived to be low. This study evaluated the role of comprehensive MRI in investigation. Methods and Materials: A total of 91 patients (36 M, 55 F) underwent MRI of the brain and face on a 1.5 Tesla system, using a standard protocol including trigeminal nerve territories in addition to cerebral and facial structures. Data collection included presenting symptomatology, and site and nature of any lesions. Evaluation of clinical significance included the effect of subsequent treatment. A patient survey was undertaken to establish patients’ perceptions of the contribution of MRI to their pain management. Results: Of 91 patients, 16 (17.6%) had a positive finding of disease, but only 6 of these (6.5%) had disease that could be directly implicated in pain, including cerebellopontine angle masses and basilar artery impression. Other patients had intracranial (2) or extracranial lesions (8) not directly related to symptoms, including sialadenitits and dental cysts. There was a high incidence of sinus mucosal thickening (33 patients, 36.3%), but no direct relationship with symptoms. A total of 32 patients responded to survey; 29 (91%) felt MRI was valuable and 22 (69%) that it had helped with their management. Patients allocated a generally high score to their care in MRI. Conclusion: MRI has a positive effect on treatment in only a small number of patients, but has value in excluding significant disease and the investigation appears to be strongly appreciated by patients. 10:48 3 T MRI 3D FIESTA demonstrating branches of intraparotid facial nerve, parotid duct, and relation with parotid tumors C. Li, B. Ai, Y. Li, L. Wu; Jinan/CN ([email protected]) Purpose: To investigate the usefulness of 3 T MR imaging 3D FIESTA in evaluation intraparotid components of the facial nerve and parotid duct, and compared with surgical findings. Methods and Materials: The 3D FIESTA sequences were used at 3 T MRI with a head coil. The most clinically useful images were acquired at parameters of 4.9/1.5 (TR/TEeff) a flip of 55В°, a field of view of 18 to 20 cm, a matrix of 512 x 320, an axial plane, no gaps, and a section thickness of 1.0 mm. Postprocessed multiplanar images were obtained with AW sdc 4.3 workstation. 20 healthy subjects and 24 patients with benign parotid tumours were studied. Parotid ducts facial nerves and tumors were identified on these images. The relationship of the tumors to the facial nerves was confirmed at surgery. Results: Facial nerves appeared as linear structures of low intensity. The main trunks and cervicofacial and temporofacial divisions of the facial nerves were identified bilaterally in 100%. Parotid ducts appeared as structures of high intensity on multiplanar images (100%). The relationships of the tumors to the facial nerves were correctly diagnosed in 23 of 24 cases (95.8%). Conclusion: 3 T MR 3D FIESTA imaging depicts the extracranial facial nerve and the parotid duct, and is useful for preoperative evaluation of parotid gland tumors. B-054 10:57 The intermediate nerve in the cerebellopontine angle: Visualisation using 3 T MRI H.P. Burmeister, P.A.T. Baltzer, A. Hadlich, P. Schmidt, G.F. Volk, O. Guntinas-Lichius, H.-J. Mentzel, W.A. Kaiser; Jena/DE ([email protected]) Purpose: The aim of this study was to evaluate the identifiability of the intermediate nerve in the cerebellopontine angle and the inner auditory canal using 3 T-MRI with respect to spatial differentiation from the facial nerve, vestibulocochlear nerve, and vascular loops. Methods and Materials: We examined 54 intermediate nerves in 27 healthy subjects. The layer thickness of the axial constructive interference in steady-state 3DFT (CISS) sequences was 0.4 mm (TR 12.18 ms, TE 6.09 ms, 512 x 512 matrix, isotropic voxels) using an 12-channel head coil. Two independent radiologists evaluated the identifiability of the nerves, roots, rootlets, and the image quality using an ordinal categorisation. Concerning the identifiability of the nerve and the image quality we evaluated the inter-rater reliability using kappa statistics. Results: Statistical testing showed that an identifiability of the intermediate nerve and spatial separation from the facial nerve, vestibulocochlear nerve, and vascular loops was possible in 22.2% with limitations and without limitations in 35.2%. So it was possible to depict at least one root in 57.4% of all cases. A depiction of rootlets was unlikely and merely possible in 2.8%. The strength of inter-rater agreement was very good concerning the identifiability (+ = 0.92) and good relating to image quality (K = 0.65). Conclusion: 3 T-MRI enables for the first time the identifiability of the intermediate nerve in the cerebellopontine angle and the inner auditory canal in a majority of cases. Therefore an assessment of the intermediate nerve becomes possible for instance in preoperative planning. B-055 11:06 CT and MRI signs in biphosphonate-associated osteonecrosis of the jaws: A tool for improving diagnostic accuracy S. Bisdas1, I. Burck2, I. Xida3, N. Chambron-Pinho2, M.G. Mack2; 1TГјbingen/DE, 2 Frankfurt a. Main/DE, 3GГ¶ttingen/DE Purpose: To characterize the radiologic appearance of biphosphonate-associated osteonecrosis (BAON) and to evaluate for distinguishing signs from radiationinduced osteonecrosis (RION) and osteomyelitis (OM). Methods and Materials: We reviewed panoramic radiographs/CT/MR scans of 42 patients with biopsy-proven BAON. Periosteal reaction, cortical erosion, sclerosis, fragmentation, destruction of the trabecular bone and sequestrum, lymphadenopathy and presence of soft-tissue mass were evaluated. We compared them with panoramic radiographs/CT/MR scans of eight patients with RION and eight patients with OM. Results: Osteonecrosis was histologically identified in the mandible of 28 patients, maxilla of 8 patients and in both jaws of 6 patients. Radiographs showed radiopaque and radiolucent areas in all BAON patients. Expansile osteolysis with A B C D E F G H S153 Friday SS 208 B-053 Scientific Sessions central sequestra (CT scans) resulted in a “bone-within-bone” sign and were highly suggestive of BAON (83% of the patients), while they did not appear either in RION or OM cases. Nearly all RION cases showed fragmentation and trabecular bone collapse. Of all the BAON patients, 60% showed involvement of the mandibular canal resulting in a “nerve road mapping” sign, which did not appear in RION/OM cases and 50% of the BAON patients demonstrated marked periostal bone proliferation resulting in a “ground-glass brim” sign. OM patients showed only reactive sclerosis. A “pseudotumor” sign (MR scans) with maxillary sinus involvement was observed in ten BAON patients and in two RION patients. Reduction of the marrow space with T1-weighted hypointensity and sclerosis were indicative of unexposed diseased bone. Reactive lymphadenopathy was not a BAON-specific finding. Conclusion: The aforementioned imaging signs, in an appropriate clinical setting, should alert to the possibility of BAON. B-056 11:15 Bone density and periodontal tissue alteration of dental implant sites: A cone beam CT study D.M. Preda1, M. Hedesiu2, C. Popita1, A.R. Ionescu1, M.F. Baciut2, G. Baciut2; 1 Bucharest/RO, 2Cluj-Napoca/RO ([email protected]) Purpose: This study was designated to evaluate variations in bone density of designated endosseous implant sites using cone beam computed tomography (CBCT) and to assess if perodontal tissue changes are related to bone density variations. Methods and Materials: A total of 85 potential sites for implant placement in the jaws from 43 patients were used. Bone density was assessed in a standardized implant area superimposed on CBCT images and the variation was evaluated using the Misch’s bone density classification. Periodontal tissue changes (involving delineation of lamina dura, crater defect and furcation involvements) were assessed on the CBCT images. The clinical examination of periodontal tissue, including clinical attachment loss, pocket depth, plaque, papilla bleeding and tooth mobility, was imaging related and established four degrees of periodontal disease. Results: CBCT results demonstrated that bone densities may vary when different areas of a designated implant site are compared. Regarding the correlation between the bone density and the periodontal tissue changes, strongly significant differences (P 0.0001) were found between the superior bone densities (D1 and/or D2) and healthy or slightly affected periodontal tissue. The inferior Misch bone densities (D3 and/or D4) are correlated with medium or severe periodontitis (P 0.0001). Conclusion: CBCT could be considered an alternative diagnostic tool for preoperative jaw bone qualitative assessment (including bone density evaluation correlated or not with morphological changes), especially since the reported radiation dose is minimal. B-057 11:24 Radio frequency-induced heating near fixed orthodontic appliances during magnetic resonance imaging at 3.0 Tesla F. Henes, J. Kemper, M. Kaul, P. Begemann, M. Feddersen, G. Adam, B. Kahl-Nieke, A. Klocke, M. Regier; Hamburg/DE ([email protected]) Purpose: The purpose of this study was to assess the radiofrequency (RF)-induced heating near fixed orthodontic appliances during the acquisition of three different sequences in high-field magnetic resonance imaging (MRI) at 3 Tesla. Methods and Materials: Ten commonly used fixed orthodontic appliances were investigated at a 3 Tesla unit (Intera, Philips Medical Systems, Best, The Netherlands) utilizing a head phantom simulating the in vivo intraoral situation. A T1w spin-echo (TR/TE 150/25 ms; FOV 350 mm; slice thickness 4 mm; SAR 3.5 W/kg), T1w turbo spin-echo (TR/TE 5,995/92 ms; FOV 350 mm; slice thickness 3 mm; SAR 4 W/kg) and T1w gradient-echo (TR/TE 4.5/1.7 ms; FOV 350 mm; slice thickness 5 mm; SAR 1.9 W/kg) sequence were acquired in axial orientation. For continuous temperature measurement, a dedicated four-channel fluoroptic thermometry system (Fotemp 4, Optocon, Dresden, Germany) was used. For each orthodontic appliance, temperature probes were placed at three predefined sites in order to perform temperature measurements during MR imaging. The fourth temperature probe was fixed to the neck of the head phantom and served as the reference. Mean temperature alterations were determined for all appliances. Results: Temperature elevations ranged from -0.3В° to 0.2В° and were negligible for all orthodontic appliances investigated. There was no difference in mean temperature alteration among the three imaging sequences performed. Conclusion: Based on the results of an experimental setting, the radiofrequencyinduced heating near orthodontic appliances does not seem to be a concern during MRI of patients undergoing orthodontic treatment. S154 A B C D E F G F H B-058 11:33 Diagnostic performance of CT for detection of open globe injury in patients with suspected orbital trauma S. Kim, J. Lee, B. Choi, S. Kim, J. Choi, H. In, Y. Lee, S. Kim; Seoul/KR Purpose: To evaluate the diagnostic performance of orbit CT for the detection of open-globe injury in patients with suspected orbital trauma. Methods and Materials: Among 392 consecutive patients who underwent CT for suspicion of orbital trauma, this study enrolled 28 patients with unilateral open-globe injury diagnosed by surgery and 28 controls without orbital trauma. Two masked readers evaluated the following characteristics of the insulted globe on CT images: the change of the anterior chamber depth (ACD), contour irregularity, volume loss, dislocated lens and intraocular hemorrhage. A generalized estimating equations analysis was used for statistical analysis. Sensitivity, specificity and diagnostic accuracy were also obtained. Another radiologist measured the ACDs of the two globes without lens dislocation and then compared the ACD difference of the two globes to figure out how the decreased ACD of the insulted globe influences the diagnostic performance on ROC analysis. Results: The sensitivity, specificity and diagnostic accuracy of CT findings were 57, 87 and 78% for decreased ACD, 68, 89 and 78% for contour irregularity, 50, 100 and 75% for volume loss, 53, 100 and 76% for dislocated lens, and 48, 100 and 74% for intraocular hemorrhage. An ACD decrease of more than 0.4 mm demonstrated the best diagnostic performance (Az = 0.918) with sensitivity of 83% and specificity of 100% (P = 0.0001). Conclusion: Although the specificities of the CT findings of open-globe injury were very high, the sensitivities were inadequate to be relied on. However, an ACD decrease of more than 0.4 mm of the insulted globe can add valuable information with high diagnostic performance for open-globe injury. B-059 11:42 Usefulness of 3D FIESTA imaging to evaluate the primary detachment of retina Q. Chen, Z. Wang, J. Xian, B. Yang, F. Yan, Q. Xu; Beijing/CN ([email protected]) Purpose: The primary detachment of retina (RD) was visualized limitedly on FSE T1WI or T2WI because the signal of subretinal fluid was similar to the vitreous. 3DFIESTA is a fast imaging sequence with high spatial resolution and good contrast between water and other organizational structures. The sensitivity of 3D-FIESTA for the visualization of primary RD and MRI findings were discussed. Methods and Materials: MR imaging was performed in 31 patients with myopic eyes and primary detachment of retina including axial FSE T1WI, T2WI and 3D-FIESTA. With or without RD, the shape and signal of the subretinal fluid were assessed in three different contrast weighting images. Results: In total, 67.7, 74.2, 100% of RD were showed, respectively, in FSE T1WI, T2WI, 3D-FIESTA in 31 myopic eyes with primary RD. RD appeared as V-shape in 16 cases, arc-shape in 15 cases. The subretinal fluid demonstrated isointense signal compared with the vitreous in 26 cases, slightly hyperintense signal in three cases, hyperintense signal in two cases on T1-weighted imaging, and isointense signal in 16 cases, hyperintense signal in 15 cases on T2-weighted imaging, and isointense signal in 19 cases, hypointense signal in 11 cases, hyperintense signal in one cases on 3D-FIESTA images. The detached retina displayed glossy thin wire shape in 16 cases and wave shape in 15 cases, and the display rate was 54.8, 64.5,100% on FSE T1WI,T2WI and 3D-FIESTA, respectively. Conclusion: 3D-FIESTA was the optimal sequence to detect primary RD with high sensitivity. B-060 11:51 Bionic ear imaging: A dose comparison study between conebeam computed tomography and multislice computed tomography N. Faccioli, M. Barillari, R. Cerini, R. Pozzi Mucelli; Verona/IT ([email protected]) Purpose: Patients treated with bionic ear implants are often children who need a strict follow-up by functional and radiological examinations, in particular MSCT scans. Dental volumetric cone beam CT (CBCT) had been suggested as a reliable diagnostic technique to acquire images of temporal bone with low ionizing radiation dose and costs. The aim of this work was to assess, in terms of radiation dose and image quality, the possibility to evaluate patients with bionic ear implants by CBCT. Methods and Materials: One hundred patients (medium age 23 y, range 7-43) implanted with Vibrant SoundBridge at the round window were followed up with CBCT (85 patients) and MSCT (15 patients). We measured the averaged tissue-absorbed doses both during a MSCT and a CBCT examination; each scan was focused on Scientific Sessions 10:30 - 12:00 Room I Vascular SS 215 Vessel wall, plaque imaging and MRA Moderators: M.G.M. Hunink; Rotterdam/NL I.P. Vulev; Bratislava/SK B-061 10:30 Evaluation of atherosclerotic plaque composition in a healthy elderly population: The Rotterdam study Q.J.A. van denBouwhuijsen, P.A. Wielopolski, S. Rozie, A. Hofman, G.P. Krestin, J.C.M. Witteman, A. van der Lugt; Rotterdam/NL ([email protected]) Purpose: Plaque vulnerability to rupture is related to the composition and morphology of the atherosclerotic plaque. With multiple contrasts, MRI can provide an effective mean to identify and quantify different components of atherosclerotic plaque in the carotid arteries. Methods and Materials: This study is performed within the framework of the Rotterdam study, a large ongoing population-based study performed in healthy subjects aged 45 years and older. Participants with asymptomatic carotid atherosclerosis defined by ultrasound were studied. We acquired MRI scans with multiple contrasts using a 1.5 Tesla MRI scanner and a bilateral surface coil. All images were linear registered. Presence of plaque, presence of different plaque components (calcification, intraplaque haemorrhage, lipid rich necrotic core (LR/NC), fibrous tissue), predominant plaque component and maximal plaque thickness were determined using previously defined MRI criteria. Results: A total of 200 subjects (age range 56.4-98.5 years; 47% men) were studied. A total of 6% of the studies were excluded due to low image quality. Forty carotid arteries were normal. In 336 carotids (89%) a plaque was present with a plaque thickness of 3.4 p 1.1 mm. Calcifications, intraplaque haemorrhage and LR/ NC were respectively seen in 69%, 27% and 23% of the plaques. The predominant component was fibrous tissue in 52%, calcification in 28%, intraplaque haemorrhage in 12% and LR/NC in 8% of the plaques. Conclusion: Carotid plaque evaluation in the healthy population is feasible. Different components of the plaque can be identified. Intraplaque haemorrhage and LR/NC, which are considered constituents of the vulnerable plaque, are present predominantly in 20% of asymptomatic atherosclerotic carotid disease. B-062 10:39 The carotid vulnerable plaque analyzed by using multidetector-row CT angiography L. Saba, R. Sanfilippo, R. Montisci, G. Mallarini; Cagliari/IT ([email protected]) Purpose: Atherosclerosis of extracranial carotid arteries is the most important cause of stroke. Our purpose was to evaluate the MDTCA plaque characteristics for vulnerability in a cohort of 630 patients. Methods and Materials: A total of 630 patients with 1,260 carotids were retrospectively analyzed. Plaque morphology (regular versus irregular), the type of the plaque (fatty, mixed and calcified), presence of ulcerations, fissured fibrous cap and thrombosis were evaluated. The degree of stenosis (according to the NASCET criteria) was also measured. We correlated MDCTA data with the presence of ischemic events. Statistic analysis was performed to determine if an interaction existed between specific plaque characteristics and presence of ischemic events. Results: A history of symptomatic ischemic episode was present in 239 patients. We found a positive correlation between the presence of fatty plaque and symptomaticity (P 0.01), ulcerations and symptomaticity (P 0.01). FFC and symptomaticity (P 0.05) and irregular morphology and symptomaticity (P 0.05). Conclusion: The result of our study indicates that some plaque characteristics are correlated with the presence of ischemic episodes; in particular, fatty plaque and the presence of ulceration are significantly associated. We think that these conditions may identify a vulnerable plaque, regardless of the degree of stenosis. B-063 10:48 Does the amount of calcifications represent the total plaque burden in the carotid artery: An analysis with multidetector CT angiography S. Rozie, D. Vukadinovic, L. van denBorne, W.J. Niessen, D.J.W. Dippel, A. van der Lugt; Rotterdam/NL ([email protected]) Purpose: To investigate the relationship between atherosclerotic plaque volume and the volume of calcifications in the carotid artery. We hypothesize that calcification volume does not represent the total plaque burden in the carotid bifurcation. Methods and Materials: Plaque volume and calcification volume of the atherosclerotic carotid plaque was measured in 120 patients (age 67.1 p 10.5 years, 78 males) with cerebrovascular symptoms and with bilateral atherosclerotic disease in the carotid bifurcation. Scanning was performed on a 16-slice MDCT scanner (Siemens, Sensation 16, Erlangen, Germany). A novel semi-automatic method was used to segment the plaque and the calcifications in the carotid bifurcation. Results: The mean plaque volume of the 240 plaques was 900 p 674 mmВі and the volume of the carotid calcifications was 139 p 175 mmВі. The plaque volume in the symptomatic artery was not significantly different from the plaque volume in the asymptomatic artery. The correlation between calcified volume and plaque volume was moderate (RВІ = 0.32). The volume of carotid calcifications was almost seven times smaller than the plaque volume (calcified plaque volume = 7.0 + 0.15 * total plaque volume). The correlation between plaque volume and calcified volume in the asymptomatic carotid arteries was weaker than in the symptomatic carotid arteries (RВІ = 0.20 and RВІ = 0.49, respectively). Conclusion: There is no strong relationship between the volume of carotid calcifications and atherosclerotic carotid plaque volume. Carotid calcifications cannot be used as an estimation of atherosclerotic carotid plaque burden. B-064 10:57 Atherosclerotic plaque ulceration in the internal carotid artery is associated with cortical ischemic stroke P.J. Homburg, T. Jansen, S. Rozie, T.T. de Weert, D.W.J. Dippel, A. van der Lugt; Rotterdam/NL ([email protected]) Purpose: Atherosclerotic plaque ulceration is a marker of previous plaque rupture which may lead to thromboembolism. We hypothesized that plaque ulceration is more prevalent in ischemic cortical strokes than in other stroke subtypes. Methods and Materials: Using MDCTA, we evaluated images of 752 patients (56% male, mean age 63 p 13 years) with cerebrovascular symptoms in the anterior cerebral circulation. Plaque ulceration was defined as extension of contrast material beyond the vascular lumen into the surrounding plaque. Strokes were clinically classified in cortical stokes, lacunar stokes and amaurosis fugax (AF). Exclusion criteria were: cardiac embolism (N=76), other stroke etiology (N=21) and poor image quality (N=2). Chi-square test was used for statistical analysis. Results: Atherosclerotic disease was present in the symptomatic carotid artery in 72%. Presence of plaque ulceration was significantly higher in the symptomatic carotid artery in patients with cortical strokes than in patients with lacunar strokes (21 vs. 7%; p 0.001) and AF (21 vs. 9%; p 0.01). There was a trend towards a higher prevalence of plaque ulceration in the symptomatic carotid artery than the asymptomatic artery of patients with cortical strokes (21 vs. 15%; p=0.06). No difference was found in prevalence of ulceration between symptomatic and asymptomatic arteries in patients with lacunar stroke (7 vs. 8%) or AF (9 vs. 11%). Conclusion: Prevalence of plaque ulceration was higher in the symptomatic carotid artery in patients with cortical strokes compared to patients with lacunar strokes and AF. Plaque ulceration was more frequent in the symptomatic carotid artery compared to the asymptomatic carotid artery in patients with cortical strokes. B-065 11:06 Blood pool-enhanced magnetic resonance angiography for the characterisation of carotid plaque composition: Correlation with endarterectomy specimen S. Tartari1, R. Rizzati1, R. Righi1, K. Capello1, R. Soverini2, E. Tsolaki3, F. Mascoli2, G. Benea1; 1Lagosanto/IT, 2Ferrara/IT, 3Bologna/IT ([email protected]) Purpose: To assess accuracy of high-resolution 3-dimensional imaging technique performed after contrast enhanced magnetic resonance angiography (CE-MRA) for evaluation of carotid plaque composition, in comparison to surgical specimen. To measure the signal intensity (SI) of different components of plaque (soft, fibrous, calcific) in post-contrast imaging. A B C D E F G H S155 Friday the temporal bone with the smallest field-of-view and low radiation dose protocol. For image quality, we obtained data about slice thickness, high and low contrast resolution, and noise by the use of an AAPM CT performance phantom. Results: Patients who underwent MSCT received a three times higher radiation dose than patients who performed a CBCT scan (0.28 vs 0.11 mSv). The anatomical structures of the middle ear were better showed by MSCT, because of high contrast resolution, but CBCT provided images adequate to evaluate the correct position of the implants. Conclusion: Because of the low radiation dose and the good quality of the images, CBCT could be considered a correct radiological technique for the postoperative examination of patients with bionic ear implants. Scientific Sessions Methods and Materials: Between January and June 2008, 75 consecutive patients underwent CE-MRA of head and neck vessels on a 1.5 T unit with parallel imaging (SENSE), with administration of a blood pool contrast agent (BPA) (Vasovist, Bayer Schering Pharma AG, Berlin, Germany). After dynamic first-pass (FP) imaging, all patients were evaluated in steady-state (SS) with an axial T1-weighted highresolution isotropic volume examination sequence (THRIVE, voxel size 0.5 mm). In all patients, we analyzed plaque morphology and composition; moreover, based on SI, carotid plaques in SS imaging were classified into one of three types (predominant component): soft tissue, fibrous or calcification. MR findings were compared with endarterectomy specimen (visual inspection) of 21/28 patients who underwent treatment (7 patients treated with carotid stenting). Results: MR was able to discriminate between plaques predominantly soft from fibrous-calcification; 6/8 patients with soft (unstable) plaque were correctly identified by MR (k=0.68). Mean SI value of soft plaque was measured 34.7. Conclusion: High-resolution isotropic imaging in SS for evaluation of carotid plaque composition is a valuable tool for assessment of carotid plaque composition, adding significant value to dynamic CE-MRA. In the detection of soft plaque, there is good agreement between BPA-enhanced MRA and surgical specimen. Further investigations with histopathological correlation are needed. B-066 11:15 Delayed enhancement of carotid atherosclerotic plaques as a marker of inflammation and instability: A magnetic resonance study using bloodpool contrast agent M. Anzidei, B. Cavallo Marincola, A. Napoli, P. Di Paolo, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: To evaluate the association between plaque inflammation, instability and delayed enhancement at MR imaging after the administration of a blood-pool contrast agent (BPCA). Methods and Materials: Blood-pool enhanced MRI was performed in 20 patients with steno-occlusive disease of carotid arteries, candidate to endoarterectomy. All examinations were performed on a 1.5 T unit after the administration of 0.03 mmol/ kg body weight of BPCA (Gadofosveset Trisodium) using high-resolution T1-w 3D GRE sequences (TR 12,TE 2.35,Voxel size:0.7*3, Matrix 512 x 512, TA 325 s) acquired at the steady-state phase. Plaque enhancement was qualitatively evaluated on a 4-point scale (1-absent, 2-poor, 3-intermediate, 4-high); clinical indexes of inflammation and histological results were compared with MRI findings to evaluate eventual association. Results: MR examinations were successfully performed in all patients; endoarterectomy was performed at least 1 week later. Plaque enhancement on delayed imaging was evaluated in 20 arteries: it was absent in 3 vessels, poor in 5, intermediate in 2 and high in 10. Histological findings of inflammation were identified in 13 out of 20 surgical specimens. Significant correlation between plaque enhancement and histological signs of inflammation was evidenced; a further correlation between clinical indexes of flogosis and blood-pool enhanced MRI findings was also demonstrated. Conclusion: The correlation between blood-pool enhanced MRI findings, histological analysis and clinical indexes represents a potential non-invasive marker for the evaluation of high-risk plaque inflammation that could be used to plan patients management. B-067 11:24 Imaging of carotid artery plaques: Correlation between 18 F-FDG PET and MRI findings R.M. Kwee, J.E. Wildberger, G.J.J. Teule, J.M.A. van Engelshoven, W.H. Mess, M.E. Kooi; Maastricht/NL ([email protected]) Purpose: Noninvasive plaque imaging by 18F-FDG PET and MRI may be used to identify vulnerable plaques (i.e., plaques which have a high tendency to cause ischemic events). 18F-FDG PET is able to assess the severity of inflammation in carotid plaques, whereas MRI allows evaluation of morphological and compositional plaque characteristics. The purpose of this study was to assess whether 18F-FDG PET and MRI findings correlate or have to be seen as two complementary (separate) imaging modalities. Methods and Materials: Thirty patients with symptomatic carotid atherosclerosis underwent standard 18F-FDG PET and a dedicated MRI protocol (time interval between both imaging modalities: 5.4 p 3.5 days). Correlations between findings of both imaging modalities were evaluated by Spearman rank correlation analyses (strong correlation: R of 0.8 or greater). Results: Spearman rank correlation analyses did not reveal strong significant correlations between mean and maximum 18F-FDG standard uptake value (SUV) of the plaque, normalized for mean blood SUV, and any of the MRI-assessed S156 A B C D E F G F H parameters. There was only a weak-to-moderate correlation between maximum 18 F-FDG uptake and maximum lipid-rich necrotic core/hemorrhage area of the plaque on MRI (Spearman R = 0.360, P = 0.05). Conclusion: There is no strong correlation between 18F-FDG PET and MRI-assessed morphological and compositional plaque characteristics. At present, 18F-FDG PET and MRI should be regarded as two complementary imaging modalities. Future prospective longitudinal studies will determine whether 18F-FDG PET or MRI (or a combination of both) is most effective in identifying vulnerable plaques. B-068 11:33 Evaluation of activity in Takayasu’s arteritis (TA) with MR angiography (MRA) using intravascular contrast media (VASOVIST)В® M. Papa, F. De Cobelli, E. Schiani, L. Dagna, M. Sabbadini, A. Del Maschio; Milan/IT ([email protected]) Purpose: Evaluation of disease activity in patients affected by Takayasu’s arteritis (TA) is a medical challenge. Correct evaluation of disease activity has relevant therapeutic implications; however, this is now based only on clinical ground features. At present no imaging technique can really differentiate between active (AD) and non active disease (NAD). VasovistВ® is a new intravascular blood-pool contrast agent recently introduced. In this study, we sought to investigate a correlation between clinical activity and enhancement in vascular wall in patients with Takayasu’s disease using MRA with VASOVIST. Methods and Materials: 20 patients with TA underwent whole body MRA; supraaortic trunks, visceral vessels, thoracic and abdominal aorta were studied. We used VASOVIST, correlating the enhancement of vessel wall thickening with the clinical suspect of disease activity and laboratory values as eritrosedimentationrate (ESR). ECG-triggered BB sequences, first pass and HR steady-state imaging were obtained in all patients. Results: 11 patients had a clinically AD, whereas the 9 remaining had NAD. Comparing the enhancement of thickenings in AD and NAD patients’ significant difference was found. The enhancement of AD vessel wall was significantly higher than NAD vessel walls (89.3 and 17.9% of increment respectively: p=0.00019). Even a statistical correlation between enhancement and ESR was observed (r=0.58; p 0.0014). Conclusion: AD patients had vivid enhancement of the outer layer of the thickened vessel wall. This can be considered the imaging expression of the adventitia’s layer inflammation in active Takayasu’s disease, while NAD patients had no wall enhancement, even in case of old wall thickenings. B-069 11:42 Role of the high resolution magnetic resonance vessel wall imaging at 3 Tesla for identifying activity of Takayasu arteritis X. Liu, J. Xu; Shanghai/CN ([email protected]) Purpose: To analyze the value of the high resolution magnetic resonance vessel wall imaging at 3 Tesla for more accurate identifying activity of Takayasu arteritis (TA). Methods and Materials: Twenty six patients who fulfilled the diagnostic criteria for TA of the American College of Rheumatology were examined for supraortic vessels by high resolution MR vessel wall imaging on a 3.0 T scanner (according to the classification of Lupi-Herrea, type I and III were included). Patients were stratified based on Kerr criteria of having unequivocally 16 active and 10 inactive phase cases, with ages ranging between 14 and 54 years. Six axial slices were scanned (three slices under the carotid bifurcation and three slices up the arch of aorta). The vessel wall image appearances were compared between active and inactive phase cases. Results: All patients had evidence of wall thickening of the primary branches of the aorta. There were statistically significant differences between active and inactive phase cases in multi-ring thickening of vessel wall (65 and 28), arterial inner wall enhancement (50 and 19), mixed-signal-intensity outer fat layer (55 and 18), (P 0.01). And there were statistically significant differences in the thickness of carotid vascular wall between two groups (P 0.05). Conclusion: By using the high resolution MR vessel wall imaging at 3.0 T, subtle mural changes and morphological differences in vessels that existed between the active and inactive phases were shown. The high resolution imaging of vessel wall benefited from the application of higher magnetic fields and proved valuable for more accurate identifying activity of TA. Scientific Sessions B-070 11:51 Quantification of arterial wall inflammation in patients with arteriits using high-resolution DCE-MRI: Correlation with 18 F-FDG PET-CT C.C. Cyran, T. Saam, S. Soubron, K. Bochmann, M. Hacker, A. Rominger, T. Pfefferkorn, M.F. Reiser, K. Nikolaou; Munich/DE ([email protected]) B-072 10:39 Novel, fully automated 3D CT lung registration algorithm O.S. Pianykh1, A.A. Bankier2; 1Newton Highlands, MA/US, 2Boston, MA/US ([email protected]) Purpose: Robust 3D lung registration is in high demand in experimental and clinical lung imaging, but its practical implementation is often hampered by human-guided landmarking. We propose a fully automated 3D lung registration algorithm. Methods and Materials: We designed a fully automated algorithm that performs lung registration as a non-rigid transform, using the rib cage as a natural landmark. First, pixels corresponding to ribs are located with HU thresholding. Second, an optimal ellipse is fit into the rib cage of each CT section. Third, ellipse centers and both major and minor axes are polynomially interpolated along the z-direction, perpendicular to section planes. The resulting nonlinear 3D rib cage model encompasses the entire lung parenchyma, using only a few parameters. Mapping of these parameters, obtained from two or more CT acquisitions, provides a non-rigid lung registration transform. We tested the algorithm in: 1) inspiratory and expiratory CT examinations, 2) dynamic CT acquisitions during expiration, and 3) follow-up examinations obtained at slightly differing lung volumes. Registration accuracy was assessed as the percentage of matched rib areas. Registration quality was assessed using a visual score. Registration time was measured. Results: The fully automated algorithm was successful in all three test scenarios. Registration accuracy was 73%, as opposed to 0.5% before registration. The overall registration quality was excellent. All CT data volumes on a 512 x 512 matrix with 650 sections or less were registered in 10 seconds. No registration required human interaction. Conclusion: Our 3D algorithm can perform fully automated non-rigid lung registration with rapid, robust and accurate results. 10:30 - 12:00 B-073 Room K Computer Applications SS 205 CAD, image registration and segmentation Moderators: N. Karssemeijer; Nijmegen/NL T. Moritz; Vienna/AT B-071 10:30 Evaluation of automated versus manual registration techniques for motion correction of lung tumors in helical breath hold CT images A. Chandler, T. Pan, W. Wei, D. Herron, E. Anderson, C.S. Ng; Houston, TX/US ([email protected]) Purpose: To compare the relative performance of manual, rigid, and non-rigid registration techniques for motion correction of lung tumors in CT images. Methods and Materials: Twenty-five patient datasets, each consisting of six limited sequential breath-hold helical volumes through an index lung tumor and one reference image obtained from a CT perfusion protocol (4x5 mm row MDCT), were evaluated. Each of the six helical volumes were registered to the reference image using manual visual and two automated intensity-based registration methods (rigid-translational and non-rigid free-form deformations (with B-splines)). For each method, 150 registrations were performed. The performance of each of the three registration techniques for the tumor regions of interest was assessed by two quantitative alignment metrics (percentage overlap and distance of center of mass (DCOM)) and by visual validation (four observers blindly scored the degree of misalignment of each registration on a 5-point scale (ranging from 2 to 50% visual misalignment)). Results: On both quantitative measures (average overlap and DCOM), rigid (87.7% and 1.08 mm) and non-rigid (91.8% and 0.41 mm) methods yielded superior performance compared to the manual method (77.6% and 2.99 mm, respectively) (p 0.0001). Visual validation confirmed these findings with 10% visual misalignment (considered clinically acceptable) occurring in 99.8 and 100% of registrations for rigid and non-rigid methods, respectively, compared to 68.5% for the manual method (p 0.0001). There was no statistical difference in clinically acceptable performance between the two automated registration methods. Conclusion: Automated registration techniques achieve significantly better alignment than manual registration, with marginal superiority of non-rigid, compared to the rigid method. 10:48 Use of a computer aided diagnosis (CAD) system to detect pulmonary nodules on multidetector-row CT (MDCT) integrated into an existing, multivendor PACS environment: A survey-based assessment P. Herzog1, S.M. Kirchhoff1, D. OвЂ�Dell2, M. Salganicoff2, M.F. Reiser1, K. Nikolaou1; 1 Munich/DE, 2Malvern, PA/US Purpose: To assess the use of a CAD-system available universally on PACSworkstations versus dedicated workstations. Methods and Materials: In 2007 a server-based CAD-system was installed, which automatically detects pulmonary nodules on MDCT-scans, with detection output going to PACS. A longitudinal survey was administered to the 34 physicians reading CT-scans of the chest, first prior to the installation and six months after. Results: Readers read from 5 to 190 scans a week. Prior to server installation, 6 of 34 (18%) used CAD at least once. 11 (32%) were aware that CAD was available institutionally. CAD was applied on an average of 22 cases weekly. Per reader utilization of CAD averaged 0.2 cases/week, ranging from 0 to 3 cases in 5 of 6 users, with one user applying it on 20 cases per week. The usefulness of CAD was rated an average of 1.4 on a 5 point scale starting with “1”. After server installation, 30 of the 34 (88%) readers used it at least once and all of them were aware that it is available. The total number of cases that CAD was (automatically) applied on averaged 384 per week, the use of CAD results in review rose to an average of 5.9 cases per user/week, the usefulness rating of an average of 3.1. Conclusion: Data shows that CAD clinical use does not solely depend on hard criteria such as detection performance but also on soft criteria such as convenience to use and availability at a PACS routine reading workplace. B-074 10:57 Artificial neural network applied to MDCT images to differentiate benign vs malignant nodules: A feasibility study F. Fraioli, M.L. Mennini, G. Serra, M. Buscema, E. Grossi, C. Catalano, R. Passariello, L. Bertoletti; Rome/IT ([email protected]) Purpose: J-Net belongs to a family of unsupervised artificial adaptive systems called active connection matrix (ACM). In these systems, each pixel is linked to its neighbours by weighted connections. Ranges of all possible connections varied in relation to the alpha parameter. The system automatically emphasizes features that could be of interest to the human eye such as edges, tissue textures and hidden shapes from digital images. We applied J-Net to undefined pulmonary nodules detected by CT scan. Methods and Materials: A total of 25 pulmonary nodules smaller than 15 mm were analyzed. Patients were scanned with an MDCT; volumetric nodule images were transferred on a dedicated software provided by a new artificial neural network. J-Net considers each image as an active connections matrix, where each node is A B C D E F G H S157 Friday Purpose: To compare 18 F-FDG-PET-CT, which is used clinically to detect inflamed arteries and to monitor anti-inflammatory treatment in patients with arteriitis, to high-resolution dynamic contrast-enhanced MRI (DCE-MRI) in its ability to measure and quantify inflammation in carotid and vertebral arteries. Results of DCE-MRI were correlated with the gold standard 18 F-FDG-PET-CT. Methods and Materials: DCE-MRI of the carotid/vertebral arteries of 12 patients with suspected arteriitis was acquired at 3 T (2D-SR-SGRE) using a dedicated 4-channel surface coil. Patients underwent 18 F-FDG-PET-CT within 1 week of the MRI scan. The maximum standardized uptake value (SUV) was measured on PET-CT images at the identical location as the ROIs were set on the MR images. Dynamic MRI signal intensity data were fitted to a two-compartment kinetic model to generate values for the following parameters: plasma flow (PF), plasma mean transit time (PMTT) and extraction flow (EF) across the capillary wall. Results: Six out of 12 patients were diagnosed with arteriitis. SUV was significantly higher in patients with arteriitis than in patients without arteriitis (1.9 vs.1.2; p 0.001). SUV correlated positively with EF (r = 0.71; p 0.001) and PMTT (r = 0.6; p 0.001) and correlated negatively with PF (r = -0.49; p 0.002). Patients with arteriitis as diagnosed by PET-CT had significantly larger EF compared to patients without arteriitis (p 0.05). Conclusion: DCE-MRI is applicable to non-invasively measure and quantify arterial inflammation with good correlation to 18 F-FDG-PET-CT. This method might be useful in the diagnosis of arteriitis and in monitoring anti-inflammatory therapy. Scientific Sessions linked to its nearest neighbors through adaptive weights. Statistical analyses were performed to evaluate possible differences in shape and morphology after the application of J-NET and to discriminate malignant from benign tumors. Results: The malignant nodules changed their shape at alpha values lower than benign ones (A or equal to -0.6); moreover, when the modification between each alpha cycle was considered, malignant nodules showed a more intense and constant modification than in benign patients. Conclusion: J-Net is able to automatically extract features of interest from digital images. It allows the reduction of image noise while maintaining the spatial resolution of high contrast structures and the expression of hidden morphological features, making the halo sign visible and showing differences between malignant versus benign nodules. B-075 11:06 Computer-aided detection on digtal chest radiography for pulmonary nodules screening Y. Xu, D.-Q. Ma, W. He; Beijing/CN ([email protected]) Purpose: To evaluate the performance of CAD system detecting the pulmonary nodule on digital chest radiography images. Methods and Materials: A total of 100 consecutive digital chest radiography examinations were independently evaluated by a radiologist and a CAD pulmonary nodule detection system (IQQATM-Chest V 1.0,EDDA) designed to identify nodules ranged from 5 to 15 mm in maximum long-axis diameter. All discrepancies between the two techniques were reviewed by two expert radiologists (with 15+ experiences of diagnosis) working in consensus with the reference CT images, and marked the locations and sizes of the “true” nodule, then stored the results of the marked nodules as golden standard in the CAD system. Results: The radiologist detected 95 nodules and the CAD system, 304 nodules. In total, 134 nodules were classified as true nodules on consensus review. Of the true nodules present, the radiologist and the CAD detected 82 (61.2%), 105 (78.4%)of 134 nodules, respectively. The radiologist missed 35 true nodules that were only detected by CAD. The CAD system missed 10 true nodules that were only detected by radiologist. The radiologist detected 112 (83.6%) nodules using the CAD system. CAD identified 199 lesions that on consensus review were false-positive nodules, a rate of 2.0 (199/100) per patient. Conclusion: CAD detected 78.4% of true nodules and detected 35 nodules in DR images not identified by radiologists, changing the imaging follow-up protocol of these subjects. Combining review of DR images by both the radiologist and CAD was necessary to identify all nodules. B-076 11:15 Semi-automated lymph node segmentation: Interobserver variability of metric and volumetric parameters in patients with non-Hodgkin lymphoma B. Buerke1, M. Puesken1, J. Gerss1, M. Weckesser1, F. Beyer1, M. Suehling2, W. Heindel1, J. Wessling1; 1MГјnster/DE, 2Erlangen/DE Purpose: This study aimed to investigate the feasibility of semi-automated metric and volumetric analysis of lymph node manifestations in patients with non-Hodgkin lymphoma compared to manual analysis. Methods and Materials: Whole body PET-CT at a slice thickness/reconstruction intervall of 3 mm/2 mm with i.v. contrast was performed in 39 patients. In total, 254 cervical, axillary and inguinal lymph nodes were evaluated retrospectively and independently by two radiologists and a semi-automated analysis software regarding RECIST diameter and volume (RECIST size range of 6 to 30 mm). Statistical analysis was performed using Student t test and intraclass correlation coefficients. Results: Automated segmentation without or minor corrections was possible in 228 out of 254 lymph nodes (89.8 %). Mean manual RECIST diameter (13.3 p 4.7 vs. 12.3 p 4.8 mm, r=0.89) and mean semiautomated RECIST diameter (14.8 p 5.2 vs. 13.9p5.3, r=0.83) between both observes were comparable whereas variation was higher for semi-automated volumetric measurements (1.6 p 2.1 ml vs. 1.7 p 2.5 ml, r=0.63). Intraobserver variability for manual and semi-automated RECIST (r=0.8) was low but RECIST diameters obtained semi-automatically were significantly oversized as compared to the manual assessments (p 0.001). Conclusion: Semi-automated RECIST, WHO and volume measurements in lymph nodes are feasible in terms of intra- and interobserver variability. A systematic and significant trend towards size overestimations requires accurate correction of the automated segmentation results. S158 A B C D E F G F H B-077 11:24 Approach to multi-sequence image analysis in diagnosis of multiple sclerosis J. Kawa1, E. Pietka1, A. Kieltyka2; 1Gliwice/PL, 2Katowice/PL ([email protected]) Purpose: Diagnosis and follow-up procedure of Multiple Sclerosis (MS) requires demyelination plaques to be detected and measured. In this study, the multisequence analysis of FLAIR and T2-WI images has been developed and tested in order to automatically segment the lesions. Methods and Materials: Axial T2-WI and FLAIR Magnetic Resonance images have been acquired from 40 patients with MS. The methodology has been designed in order to automatically segment the plaques using fuzzy clustering algorithms in kernel space, connectivity analysis and statistical models. Knowledge based corrections have been applied to increase performance of the method. During evaluation, a test subset of randomly selected cases have been created. The 20 test cases have been radiologically examined and the plaques have been outlined. Results: The performance has been verified by interobserver comparison with the gold standard. The evaluation was based on Dice Similarity Coefficient (79%, std. 8% with intraobserver 83%), sensitivity (89%, std. 8.5%, cf. intraobserver 90%) and specificity measure (99.95%, std. 0.04%, cf. intraobserver 99.99%). Visual comparison revealed reduced accuracy for lacunar lesions and plaques located within the grey matter. Conclusion: An automatic methodology can be used for segmentation of MS lesions. The obtained accuracy permits for fast analysis and estimation of volume of the demyelinated tissue. B-078 11:33 Performance of a prototype computer aided diagnosis (CAD) tool for the detection of lymph nodes at multidetector-row CT P. Herzog, M.F. Reiser, G.T. Schmidt, R. Korn, G. Binnig, K. Nikolaou; Munich/DE Purpose: To assess the performance of a CAD tool for the detection of lymph nodes. Methods and Materials: 18 MDCT datasets of the chest or abdomen were randomly selected. Axial images of 5 mm slice width were independently analysed by two readers, asked to report every LN greater than 5 mm in maximum diameter. Furthermore, all studies were additionally submitted to a CAD tool. A consensus panel (CP) of two experienced radiologists validated the LN found by both, the readers and the CAD tool, and also detected additional lesions. Results: CP confirmed 589 lesions with diameters ranging from 5 - 64 mm. 301 (51%) LN were correctly found by the readers, while 288 were missed (49%). 102 lesions were solely marked by reader 1, while 165 were detected only by reader 2. 34 lesions were detected by both readers. Inter rater agreement revealed a Cohen’s-Kappa-value of 0.089. CAD detected 851 candidate lesions; 442 were confirmed by CP (52%) while 409 were dismissed as false positives (48%). 260 nodes were marked by both, CAD and the readers together (42%); 241 lesions (41%) were found uniquely by CAD and 41 nodes (7.0%) were found solely by the readers. 47 LN (8.0%) were found only by the consensus panel. Working alone, reader 1 had a sensitivity of 23%, reader 2 of 34%, whereas an individual reader plus CAD would have had an sensitivity of 84 and 91%, respectively. Conclusion: CAD has the potential to significantly increase the number of detected lymph nodes. B-079 11:42 Automated segmentation of volumes on MR imaging: Validation, accuracy and relationship of error to imaging parameters S. Ghosh-Ray, S. Rosa, A.P. Toms, A. Clark; Norwich/UK ([email protected]) Purpose: Automated volume segmentation is available on a number of platforms, including open source software, and is useful for monitoring tumour size during treatment. However, the accuracy of these tools depends on imaging parameters such as slice thickness therefore the purpose of this study is to determine the relationship between volume, slice thickness and standard error of measurement (SEM) during volume segmentation on MRI. Methods and Materials: A phantom was constructed using acrylic spheres (12.7-76.2 mm diameter) machined to high tolerances. High resolution T2W MR images were acquired at 0.9, 2, 4, 6 and 8 mm slice with either no inter-slice or a 20% inter-slice gap. Two observers independently measured the volumes of the spheres using an automated propagating segmentation tool (OsirixВ®), which were then compared with the known volumes. Results: The accuracy of the segmented volumes decreased proportionally with the volume of the spheres (SEM range: 1.76 to 14.11%). As slice thickness and Scientific Sessions B-080 11:51 CAD-based analysis of vascularization pattern of axillary lymph nodes in breast MRI and ist diagnostic potential A. Malich, A. Kott, D. Hentrich; Nordhausen/DE ([email protected]) Purpose: MR-based analysis of lymph nodes is still a diagnostic challenge. The study is aimed to analyze dynamic pattern of metastatic and non metastatic nodes in comparison to those of the malignant tumor using different CAD-systems. Methods and Materials: Confirma (USA, CAD1) and CADSciences (USA, CAD2) were used. 100 breast-MRI containing a malignant lesion were analyzed using both modalities including axillary edge and nodes (histologically proven). 0.1 mmol Gd-DTPA Gadolinium/kgbw were applied. All available data including permeability, extracellular volume fraction, peak uptake, worst wash in, worst wash out, dynamic enhancement of the entire lesion/node were matched. Results: Using both CAD-systems, peak contrast uptake differed highly significant between metastatic and non metastatic node suggesting being stronger and faster at metastatic nodes (CAD1: 423%/191%; CAD2: 1641%/751%). Wash out occurs in benign and malignant nodes similarly. There was no significant correlation of dynamic distribution of the primer malignant lesion and the metastatic node neither regarding the extent of uptake nor regarding the percentage distribution of enhancement pattern of malignancy and related metastasis. Both CAD-systems differed significantly regarding volume calculation and percentage distribution of contrast uptake. Using cut off of 240% initial uptake (CAD1) allows an accurate discrimination of malignant and benign nodes (sensitivitiy 89%, specificity 85%). Conclusion: Maximum (peak) contrast uptake and rapid initial uptake differ significantly dignitiy-dependent amongst the several nodes not influenced by alternative CAD-technologies. Total value of contrast uptake of both CAD-systems differ due to significantly different volume calculations, relative differences benign vs. malignant nodes are similar, however. 10:30 - 12:00 Room L/M Neuro SS 211 Diffusion tensor imaging Moderators: Q.-Y. Gong; Chengdu/CN W. Van Hecke; Antwerp/BE B-081 10:30 Combined MR spectroscopy and diffusion tensor imaging to evaluate the therapy of transplanting olfactory ensheathing cells for amyotrophic lateral sclerosis Y. Xue, R. Zhai, K. Tan; Beijing/CN ([email protected]) Purpose: To evaluate the safety and effectiveness of transplanting olfactory ensheathing cells to treat amyotrophic lateral sclerosis (ALS) using 1H-MRS in conjunction with DTI. Methods and Materials: 15 ALS patients and 12 healthy control subjects were studied with 1H-MRS and DTI on GE Sigma 3.0 T MR system. The NAA/Cr ratios and FA were measured in the brain before and after receiving olfactory ensheathing cells (OECs) transplantation (2 weeks and 6 months) in ALS. Results: 1) Before treatment, compared with that of control groups, the FA values of ALS reduced significantly in the all detected sites in the brain, and the NAA/Cr ratios decreased in the subcortical white matter and corona radiata. 2) 2 weeks after treatment, the FA values remained unchanged, and the NAA/Cr increased obviously in the posterior limb of the internal capsule and subcortical white matter. 3) 6 months after treatment, the FA values increased significantly in the corona radiata and the corpus callosum. While the ratios of NAA/Cr decreased significantly in the subcortical white matter. Conclusion: Both DTI and 1H-MRS can be served as potential means to evaluate therapeutic effectiveness. The improved NAA/Cr ratios (2 weeks) and FA values (6 months) in some locations in the brain supported the point that OECs transplantation might be benefit for ALS, but the difference of the results from 1H-MRS and DTI need further investigation. B-083 10:39 Whole brain diffusion tensor imaging in Parkinson’s disease: Changes in the olfactory tract and the cerebellum K. Zhang, K. Li, C. Yu; Beijing/CN ([email protected]) Purpose: The white matter of the brain is involved in the pathologic processes of Parkinson’s disease (PD). Previous diffusion studies on PD have focused on the differential diagnosis and found the differences in diffusion indexes between patients with PD and patients with atypical parkinsonian disorder (APD). But few diffusion studies have focused on the damage of the white matter integrity itself in patients with PD using voxel-based analysis. The purpose of our study is to investigate the abnormal diffusion in the brain white matter of patients with PD in a whole brain manner. Methods and Materials: Diffusion tensor imaging (DTI) of the brain was obtained in 26 patients with PD and 26 age- and sex-matched normal subjects. The differences in the fractional anisotropy (FA) and mean diffusivity (MD) between groups were studied with the voxel-based analysis (VBA) of the whole brain DTI data. The correlations between the abnormal diffusion and the clinical data including the olfactory function were also evaluated in the PD patients. Results: Decreased FA was found in the bilateral cerebella and decreased FA and increased MD were found in the olfactory tract area. Moreover, there was a significant correlation between the FA in the cluster of the right medial cerebellum white matter and the threshold of olfactory identification. Conclusion: Our research suggests that the damage of white matter in the cerebellar and olfactory tract area might be the underlying mechanism for olfactory dysfunction in PD. B-084 10:48 Human lymphotropic virus type I associated myelopathy/tropical spastic paraparesis: A study of the white matter with diffusion tensor MR imaging E.L. Gasparetto, L.H. da Cruz Jr, T. Doring, R. Borges, R.C. Domingues, R.C. Domingues; Rio de Janeiro/BR ([email protected]) Purpose: To evaluate the diffusion tensor imaging (DTI) abnormalities in the white matter of patients with human lymphotropic virus type I associated myelopathy/ tropical spastic paraparesis (HAM/TSP). Methods and Materials: A total of 11 patients with HAM/TSP and a control group underwent brain MRI at 1.5 T scanner with conventional protocol and DTI. The DTI data were post-processed and fractional anisotropy (FA) maps were calculated. The FA values were measured with a ROI-based technique in the white matter lesions (WML), normal-appearing white matter (NAWM) around them, as well as NAWM more than 1 cm distant from the lesions and contralateral. In addition, using a voxel-based technique, the mean FA of the whole brain, grey matter and white matter was compared between the two groups. Results: The FA was significantly reduced in the WML (mean FA = 0.285) and in the NAWM around them (mean FA = 0.386) compared with controls (mean FA = 0.662) (p 0.001). However, there was no significant reduction in FA of the NAWM distant from the lesions (mean FA = 0.602) and contralateral to the lesions (mean FA = 0.587) (p 0.05). Finally, no significant differences were observed in the mean FA of the whole brain, grey matter and white matter between the two groups (p 0.05). Conclusion: In this group of HAM/TSP, we observed reduced FA values in the WML and NAWM around them, but no significant abnormalities in the NAWM distant from the lesions. Different from other demyelinating diseases, the infectious or inflammatory process in patients with HAM/TSP seems to be restricted to the WML and the NAWM around them, preserving the remaining NAWM. A B C D E F G H S159 Friday effective slice thickness increase so the error for a known volume increases. The MR acquisitions with inter-slice gaps produced volumes that were closest to the known volume of the spheres. The SEM for a known lesion diameter (d) and slice thickness (t) can be predicted from the following formulae: With a 20% inter-slice gap: SEM = 29.02e-0.06d/t. With no inter-slice gap: SEM = 32.11e-0.04d/t. Conclusion: Automated volume segmentation is an accurate tool for measuring volumes of spheres within a phantom. The formulae presented above can be used to plan MR examinations for a given SEM. Scientific Sessions B-085 10:57 Changes of DTI in tMCAO rats with acupuncture therapy F. Miao, Z.-Y. Wu, Q.-Y. Xiang; Shanghai/CN ([email protected]) Purpose: To assess the effects of acupuncture therapy in tMCAO rats and discuss its mechanisms. Methods and Materials: SD rats were divided into three groups. Group 1 underwent tMCAO and received acupuncture therapy, group 2 also underwent tMCAO but had no therapy, and group 3 underwent sham operation. The evolutions of diffusion tensor imaging (DTI) features of ischemic lesions at acute to chronic periods were assessed and the correlations with behavioral tests, DTI appearances, and histopathological changes were discussed. Results: Behavioral scores of group 1 reduced gradually with acupuncture therapy and no significant change was seen in group 2. rADC and rFA values in the center and the edge of ischemic lesions reduced at first and then elevated in varying degrees. In the two tMCAO groups, only the changes in rFA value at the edge of ischemic lesions had significant difference. More significant increase of GAP-43 and synaptophysin protein expression was found in group 1 than in group 2 and group 3. No significant correlations were found between behavioral test results, DTI appearances, and immunohistochemical results when data was grouped. Conclusion: The acupoints applied in this study were effective for the functional recovery, and improving neuronal regeneration might play a certain role in mechanism of acupuncture therapy to poststroke paralysis of the limbs in these rats. MRI, in particular FA value of DTI, was an appropriate parameter to evaluate the recovery status. B-087 11:06 Quantitative brain MRS and DTI on the impact of fluoxetine in MS P.E. Sijens, J.P. Mostert, R. Irwan, J. Potze, J. De Keyser, M. Oudkerk; Groningen/NL ([email protected]) Purpose: The antidepressant fluoxetine stimulates astrocytic glycogenolysis, which serves as an energy source for axons. In multiple sclerosis patients, fluoxetine administration may improve the energy supply to neuron cells and thus inhibit axonal degeneration. We studied this phenomenon by diffusion tensor imaging (DTI) and 1H magnetic resonance spectroscopy (MRS). Methods and Materials: In a pilot study, 15 multiple sclerosis (MS) patients were examined by quantitative DTI (b = 0 and 1,000 s/mm2) and 1H MRS (TR/TE 1,500/135 ms) in order to quantify the brain tissue diffusion properties (fractional anisotropy, apparent diffusion coefficient) and metabolite levels (choline, creatine and N-acetylaspartate) in the cortical gray matter brain tissue, in normal appearing white matter and in white matter lesions. Results: After oral administration of fluoxetine (20 mg/day) for 1 week, the DTI and MRS measurements were repeated and after treatment with a higher dose (40 mg/day) during the next week, a third series of DTI/MRS examinations was performed in order to assess any changes in diffusion properties and metabolism. One trend was observed in the gray matter tissue, a decrease of choline measured at weeks 1 and 2 (significant in a subgroup of 11 relapsing remitting/secondary progressive MS patients). In the white matter lesions, the apparent diffusion coefficient was increased at week 1 and N-acetylaspartate was increased at week 2 (both significant). Conclusion: These results provide evidence of a neuroprotective effect of fluoxetine in multiple sclerosis by the observed partial normalization of the structure-related MRS parameter N-acetyl aspartate in white matter lesions. B-088 11:15 Diffusion tensor imaging of high-grade gliomas and brain metastases W.H. Flatz1, O. Dietrich1, S.O. SchГ¶nberg2, B.B. Ertl-Wagner1, M.F. Reiser1; 1 Munich/DE, 2Mannheim/DE ([email protected]) Purpose: The objective of our study was to detect and evaluate intra- and peritumoral mean diffusivity and fractional anisotropy to differentiate between high-grade gliomas and brain metastases. Methods and Materials: Eighteen previously untreated patients suffering from histologically proven high-grade glioma and 14 patients diagnosed with brain metastases from breast cancer were examined in our study. MRI was performed using a 3 T scanner acquiring DTI images with 12 directions. The regions of interest (ROI) for DTI evaluation were positioned into different parts of the tumor, normal appearing white matter and the vasogenic edema adjacent to tumor depicted as abnormal areas in T2-weighted images. S160 A B C D E F G F H Results: Significant decrease of fractional anisotropy (FA) (p 0.005) and significant increase of mean diffusivity (MD) (p 0.005) were found in the peritumoral regions compared to normal appearing white matter. For brain metastases the peritumoral MD was significantely increased compared to high-grade gliomas (p 0.005). Peritumoral FA showed no significant differences among the two patient groups. Intratumoral FA was increased in high-grade gliomas and in metastatic disease. Conclusion: Due to increased extracellular water content, diffusion parameters show a pathological change within the peritumoral vasogenic edema in both high-grade gliomas and metastases. Unlike FA, MD can be used to differentiate between high-grade gliomas and metastatic tumors, pointing towards probable tumor infiltration characterized by MD values. B-089 11:24 Combined study of fMRI and DTI for working memory of children with learning disability C. Pan; Wuhan/CN ([email protected]) Purpose: To examine brain activity of working memory and anisotropy of the fronto-parietal white matter in children with learning disability (LD) by combining fMRI and DTI. Methods and Materials: Twelve children with LD aged 10-12 years and twelve children matched in age and sex as normal control were investigated. Brain activity of working memory was measured using BOLD-fMRI during performance of paced visual serial addition test. The data group studies were analyzed using SPM2. White matter was investigated using diffusion tensor imaging (DTI). The activity map were overlaid upon FA maps. The correlation between BOLD response and FA values of the ROIs in fronto-parietal lobe were statistically analyzed. Results: 1. In bilaterally inferior parietal lobe, inferior frontal gyrus, and left superior frontal gyrus, left medial frontal gyrus and left cingulate gyrus, children with LD showed weaker activation than matched children. In left superior parietal lobe and right inferior frontal gyrus, children with LD showed no activation. 2. The white matter FA values in left fronto-parietal (P=0.027), left parietal lobe (P=0.031) and left frontal lobe (P=0.018) in children with LD were lower than matched children. 3. Both in two group children, the mean of BOLD activated voxels in the dorsolateral prefrontal cortex (DLPFC) has the positive correlation with FA values in frontoparietal white matter. Conclusion: The weaker BOLD response and lower FA values of children with LD in fronto-parietal lobe suggests the poorer maturation of grey and white matter, which maybe is the pathogenesis of learning disorders. B-090 11:33 Diffusion tensor imaging in patients with idiopathic normal pressure hydrocephalus: A pilot study E. Hattingen, A. Jurcoane, O. Singer, O. Singer; Frankfurt/DE ([email protected]) Purpose: Diffusion tensor imaging (DTI) parameters were investigated in patients with idiopathic normal-pressure hydrocephalus (iNPH) to evaluate micro-structural damage of brain tissue due to chronic ventricular dilatation. Methods and Materials: 11 patients with iNPH and 10 healthy controls underwent MRI at 3 Tesla including DTI examination with 12 gradient directions. iNPH patients were scanned before and after lumbar CSF withdrawal tests. Tract-based spatial statistics and manually defined regions of interest approaches were performed to analyze differences in fractional anisotropy (FA) and mean diffusivity (MD) between patients and controls. In iNPH patients, changes in FA and MD before and after lumbar CSF drainage were analyzed. Results: Compared to the control group, iNPH patients had significantly higher MD values in both the periventricular corticospinal tract (CST) and the corpus callosum (CC) while FA values were significantly higher in CST but lower in the CC. In iNPH patients, MD decreased significantly in the CC after lumbar CSF drainage. Conclusion: Significant changes of MD and FA in iNPH patients imply mechanical and microstructural changes in periventricular functional relevant brain structures. These changes are at least partially reversible. Further investigations of DTI parameters in iNPH, possibly also observing the effect of CSF shunting, may add to a better understanding of the pathophysiological mechanisms leading to iNPH. Scientific Sessions 10:30 - 12:00 Room N/O Abdominal Viscera (Solid Organs) Liver: Hepatocellular carcinoma Moderators: I. Bargellini; Pisa/IT D.J. Lomas; Cambridge/UK B-091 10:30 Value of double-contrast liver MRI at 3.0 T in differentiating welldifferentiated hepatocellular carcinomas from dysplastic nodules: Multivariate analysis M. Yoon, S. Kim, J. Lee, J. Lee, J. Han, B. Choi; Seoul/KR ([email protected]) Purpose: To determine significant MRI findings for differentiation of well-differentiated hepatocellular carcinomas from dysplastic nodules on double-contrast MRI. Methods and Materials: A total of 28 transplantation recipients with 32 W/D HCCs and 33 DNs underwent DC-MRI using SPIO and Gadolinium agents on a 3 T unit. Precontrast (NCE) T1W GRE and T2W FSE images and SPIO-enhanced T2W FSE and T2*W GRE images were obtained. After Gd administration, arterial (AP), portal (PP) and equilibrium images were scanned. Two reviewers analyzed the signal intensities on each sequence. On AP images, the degree of enhancements was categorized into four groups: no, minimal, moderate and strong. For quantitative analysis, the relative arterial enhancement ratio (RAE) was calculated. Each variable was evaluated with univariate tests and then with multivariate logistic regression analysis to find the most predictable finding. Results: Of the 32 W/D HCCs, 20 showed iso or high SI on NCE T2W images, while 20 of 33 DNs showed low SI. On post-SPIO and pre-Gd T1W GRE images, 28 W/D HCCs showed iso or high SI while 24 DNs showed low SI. On post-Gd AP images, 22 W/D HCCs revealed at least minimal enhancement, whereas 31 DNs did not show any. RAE of W/D HCCs (40.4%) was also significantly larger than that of DNs (16.2%). Multivariate analysis revealed subjective degree of enhancement on AP images and was the only variable that independently differentiated W/D HCCs from DNs. Conclusion: Subjective degree of enhancement on post-SPIO and Gd AP images is the only independent variable that distinguishes W/D HCCs from DNs on DC-MRI. B-092 10:39 Can MR imaging predict microvascular invasion in patients with hepatocellular carcinoma? J. Lonjon Blanc, V. Schembri, B. Gallix, J.-M. Bruel; Montpellier/FR ([email protected]) Purpose: The aim of this study was to determine MR features predictive of microvascular invasion in patients with HCC nodules before hepatic resection. Methods and Materials: 54 patients who underwent curative resection for HCC (n=30) or liver transplantation (n=24) were included in this retrospective study. Dynamic MR imaging was performed within 6 months before surgery (mean 82 days, SD 75 days) were evaluated regarding nodule size and number, T2 hyper-intensity, capsule visualization and integrity, presence of an hyper-vascularisation, wash-out, portal shunt and thrombosis. Results were correlated with pathological analysis. Results: Irregularity of the peripheral part of the nodule or disrupted capsule by MR was correlated with microvascular invasion (p 0.05). Nodule size superior to 3 cm significantly correlated with microvascular invasion (p 0.001). Number of nodules, T2 signal intensity, vascular enhancement, arterio-portal shunt and presence of a wash-out were not significantly correlated with vascular invasion. Conclusion: HCC nodule size measuring more than 3 cm and irregularity of the peripheral surface or capsule of the nodule as determined by MR imaging are predictive of microvascular invasion. B-093 10:48 Loss of typical wash-out pattern of hepatocellular carcinomas on doublecontrast liver MRI: Overcoming with quantitative analysis of enhancement patterns J.-H. Yoon, J. Lee; Seoul/KR ([email protected]) Purpose: To investigate if quantitative analysis can overcome a major drawback of double-contrast liver MRI that conceals typical wash-out enhancement pattern of hepatocellular carcinomas. B-094 10:57 Intraindividual comparison of hepatic venous phase and delayed phase for the detection of washout contrast-enhancement pattern of HCC on MDCT of the liver A. Furlan1, G. Brancatelli2, D. Marin3, G. Palermo Patera2, A. Ronzoni4, M. Midiri2, M. Bazzocchi1, A. Vanzulli4; 1Udine/IT, 2Palermo/IT, 3Rome/IT, 4Milan/IT ([email protected]) Purpose: To retrospectively compare the hepatic venous phase (HVP) with the delayed phase (DP) for the detection of washout contrast-enhancement pattern of HCC lesions on MDCT of the liver. Methods and Materials: The study cohort comprised 30 cirrhotic patients (25 men, 5 women; mean age, 57 years; range, 33-66) who underwent multiphasic 64-slice MDCT of the liver during 90 days before liver transplantation. CT was performed immediately before i.v. contrast medium administration (2 mL/Kg body weight of iomeprol, 350 mgI/mL at 3.5-4.0 mL/s) and during the hepatic arterial dominant phase, HVP and DP, obtained respectively at 12, 55 and 120 s after the trigger threshold (120 HU at the level of the abdominal aorta) using automatic bolus tracking. Two radiologists qualitatively evaluated the CT images during the HVP and DP for the detection of tumor washout contrast-enhancement pattern. Additionally, tumor-to-liver contrast-to-noise ratio (CNR) was measured for each lesion at both phases. Results: At pathologic examination of explanted livers, 61 HCCs (mean size, 1.6 cm; range, 0.8-4.2 cm) were confirmed in 27 patients. Of the 61 HCCs, 47 (77%) were detected on MDCT. A significantly higher number of tumors demonstrated a washout contrast-enhancement pattern during the DP (19 of 47, 40%) compared to the HVP (12 of 47, 26%) (P 0.0001, McNemar’s test). Lesion-to-liver mean CNR increased significantly during the DP (-2.07p1.2) compared to the HVP (-1.33p1.4) (P = 0.0003, Student’s t-test). Conclusion: DP is superior to HVP in the detection of washout contrast-enhancement pattern of HCC at multiphasic 64-section MDCT of the liver. B-095 11:06 Histologic grading of hepatocellular nodule in cirrhotic liver disease: Analysis of characterization performance of DW MRI, Gd-EOB-DTPAenhanced MRI and a combined protocol S. Zaid, L. Crespi, T. Ierace, P. Marelli, L. Solbiati; Busto Arsizio/IT ([email protected]) Purpose: To assess the characterization accuracy of histologically graded liver nodules in cirrhotic liver using diffusion-weighted (DW) MR, Gd-EOB-DTPA-enhanced MRI and a combination protocol. Methods and Materials: A total of 28 cirrhotic patients with 33 pathology-defined liver lesions underwent MRI scans, evaluated independently and prospectively by three blinded radiologists with equivalent experience. DW protocol included routine axial T1W, T2W and DW sequences; Hepatocyte-specific protocol consisted of T1W, T2W and Gd-EOB-DTPA triphasic and late hepatocyte-specific phase; combined protocol included both DWI and Gd-EOB-DTPA MRI protocol. Histologically, liver lesions were classified as dysplastic nodules (DN), well-differentiated (WD) HCC and moderately or poorly differentiated (M-PD) HCC. Each lesion was classified according to its ADC value on DW sequences with three increasing b-values (50, 400 and 800 sec/mmВІ) and its enhancement features at Gd-EOB-DTPA arterial, portal and late (at 20 min) phases, with categorized signal intensity at late phase (no hepato-specific absorption, low, subtle, iso). A B C D E F G H S161 Friday SS 201b Methods and Materials: Forty-four histologically proven HCCs in 41 patients were included in the study with a control group of 100 hemangiomas of 73 patients. All patients underwent double contrast liver MR [superparamagnetic iron oxide (SPIO) and then gadolinium (Gd) enhancement]. Qualitative analysis with visual inspection was performed regarding the presence of arterial enhancement and washout of HCCs. Regions-of-interest of each lesion and its adjacent liver parenchyma were measured on T1W dynamic sequences after Gd enhancement. Lesion-to-liver ratio on all sequences and the difference of lesion-to-liver ratio among each dynamic phase were calculated. Data from all lesions were analyzed using the Student t-test and receiver operating curve (ROC) analysis. Results: Lesion-to-liver ratio on dynamic T1W images over time revealed decrease in 91% of HCCs whereas visual inspection revealed washout pattern in only 23% of HCCs. As a control group, 86% of hemangiomas showed increase of lesion-toliver ration during dynamic phases. The most significant parameter between HCCs and hemangiomas was lesion-to-liver ratio difference between arterial phase and 3 minute-delayed sequences (p=0.001, Az=0.94). Conclusion: Quantitative analysis of tumoral enhancement on dynamic phases may overcome the major pitfall of double-contrast liver MRI. Scientific Sessions Results: DW protocol allowed correct characterization of 28 (84.8%) liver nodules, with a superiority in identifying foci of M-PD HCC within WD HCC. Liver-specific contrast agent protocol characterized 26 (78.7%) liver nodules, displaying higher accuracy in distinguishing between DN and WD-HCC. The combined assessment improved the characterization performance by up to 96.9 %. Conclusion: Liver nodules characterization in chronic liver disease significantly benefits from the association of DW sequences and liver-specific Gd-EOB-DTPA. B-096 11:15 Intraindividual comparison of gadoxetic acid (Gd-EOB-DTPA) enhanced MR imaging and multiphasic 64-slice CT for the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis M. Di Martino, D. Marin, A. Guerrisi, D. Geiger, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: To intraindividually compare Gadoxetic acid (Gd-EOB-DTPA) enhanced MRI and 64-slice CT for the detection of HCC in patients with cirrhosis. Methods and Materials: Informed consent and ethical approval were obtained. Thirty-seven consecutive patients with 67 HCC nodules underwent MRI at 1.5 T (Avanto, Siemens) and 64-slice CT (Sensation 64, Siemens) at a mean interval of 14 days (range 10-20 days). MR acquisitions comprised unenhanced breath-hold T2W images and volumetric 3D Gd-EOB-DTPA-enhanced (0.1 mmol/kg; PrimovistВ®) T1W GRE images acquired at 25, 60, 180 s (dynamic phase) and 20 min (hepatobiliary phase). 64-slice CT was performed with 0.6 x 64 mm collimation, 3-mm section thickness, 250 mAs, 120 kVp. A triple-phase protocol was started 18, 60 and 180s after reaching a trigger threshold of 150 HU above baseline CT number of the aorta. Image analysis was independently performed by three observers in two sessions separated by 4 weeks. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic (AFROC) method. Sensitivity, specificity and positive predictive value (PPV) with corresponding 95% confidence intervals were determined. Results: On a lesion-by-lesion basis, the mean area under the AFROC curve for Gd-EOB-DTPA MRI (0.88) was significantly higher than that of CT (0.77) (P 0.05), the mean sensitivity (81.1%) and specificity (94.7%) of Gd-EOB-DTPA MRI was significantly higher than that of CT (65.5%,) and (84.2%) (P 0.05). No statistical significant difference was obtained in terms of PPV. Conclusion: Gd-EOB-DTPA-enhanced MRI is significantly more accurate, sensitive and specific than 64-slice CT for the diagnosis of HCC in patients with cirrhosis. B-097 11:24 A two-centre study for the comparison of GD-EOB-DTPA (PRIMOVIST)enhanced MRI versus triple-phase MDCT for the detection of hepatocellular carcinoma in cirrhosis A. Luca1, L. Grazioli2, S. Caruso1, R. Tinti2, M. Milazzo1, M. Bondioni2; 1 Palermo/IT, 2Brescia/IT ([email protected]) Purpose: To compare the diagnostic performance of MRI using gadoxetic acid (Gd-EOB-DTPA, Primovist, Bayer-Schering Pharma, Berlin, Germany) with triplephase multidetector CT for the detection of HCC in cirrhotic patients. Methods and Materials: 110 cirrhotic patients with HCC underwent MRI and MDCT. Images were acquired before and after contrast agent administration in arterial, portal venous and equilibrium phases. Hepatobiliary phase images were obtained 5, 15 and 20 minutes after Gd-EOB-DTPA. The diagnostic accuracy for HCC was evaluated with nodule-by-nodule and patient-by-patient analyses. Sensitivity analyses were performed according to overall HCC, main HCC and secondary (satellite or metastatic) HCC. Results: On a per nodule basis, overall sensitivity of Gd-EOB-DTPA-MRI for the diagnosis of HCC was significantly superior to triple-phase MDCT (178/185 [96%] vs. 156/185 [84%], P = 0.009). Gd-EOB-DTPA-MRI and MDCT detected 106/110 [96%] and 107/110 [97%] main HCC, respectively (NS). Sensitivity of Gd-EOB-DTPA-MRI for detection of secondary HCC was significantly superior to MDCT (72/75 [95%] vs. 49/75 [65%], respectively, P 0.005). On a per patient basis, in 86 (78%) patients there was a concordance between MRI and MDCT, in 20 (18%) patients MRI alone detected 29 HCC and in 4 (4%) patients MDCT alone detected 7 HCC; the mean diameter of lesions detected with a single imaging modality was 19.3 mm and the size class was 10 mm (n=3), 10-20 mm (n=24) and 20 mm (n=9). Conclusion: In patients with cirrhosis, Gd-EOB-DTPA-enhanced MRI is more accurate than triple-phase MDCT for detection and characterization of small satellite or metastatic HCC. S162 A B C D E F G F H B-098 11:33 Evaluation of additional value of SPIO-enhanced MR imaging for noninvasive imaging diagnosis of hepatocellular carcinoma in cirrhotic liver: Validation of EASL diagnostic criteria H. Yoo, J. Lee, J. Lee, S. Kim, S. Kim, J. Han, B. Choi; Seoul/KR ([email protected]) Purpose: To validate the EASL diagnostic criteria for Hepatocellular Carcinoma (HCC) in cirrhotic liver and to determine the additional value of superparamagnetic iron oxide (SPIO)-enhanced MRI in the diagnosis of HCC. Methods and Materials: This study included 108 patients with 153 histologically confirmed hepatocellular nodules, i.e. 26 dysplastic nodules (DNs), and 127 HCCs, who underwent dynamic-CT and double-contrast-enhanced (DCE) MRI with SPIO and gadobenate-dimeglumine. Two reviewers analyzed the hypervascularity of the nodules on dynamic CT and MR images, and their signal intensity on SPIOenhanced images using consensus. First, the reviewers were requested to make a diagnosis of HCC according to EASL recommendation. Second, among the nodules that did not meet the EASL-criteria using CT and dynamic-MRI, nodules with a low uptake of SPIO on MRI were also considered as HCCs. Sensitivity, specificity were assessed based on EASL diagnostic criteria for HCC using both CT and dynamicMRI and then, reassessed in combination with SPIO-enhanced MRI. Results: Of 127 HCCs, 79 HCCs were larger than 2 cm in diameter, 37 HCCs were between 1 and 2 cm, and 11 HCCs were smaller than 1 cm. A significant improvement in the sensitivity (78-95%) was achieved by adding SPIO-enhanced MR images to EASL-criteria (p 0.01). When EASL-criteria were applied for the HCCs between 1 and 2 cm, of 37 HCCs, diagnosis was correct for 21 lesions (57%) with EASL criteria, and 30 lesions (81%) with combined SPIO-enhanced MR images. Conclusion: Adding SPIO-enhanced images to the two dynamic imaging modalities, provides improvements in the non-invasive diagnosis of HCCs compared with only EASL criteria, especially in making a diagnosis of non-hypervascular HCCs. B-099 11:42 Prospective validation of AASLD guidelines for the early diagnosis of hepatocellular carcinoma in cirrhotic patients L.V. Forzenigo, A. Sangiovanni, M.A. Manini, M. Iavarone, M. Fraquelli, R. Romeo, P. Biondetti, M. Colombo; Milan/IT ([email protected]) Purpose: Confident diagnosis of HCC in cirrhotics under US surveillance is currently based on invasive and non-invasive imaging criteria. We evaluated the sensitivity, specificity and positive and negative predictive values (PPV, NPV) of contrast-enhanced ultrasound (CE-US), CT and MRI in patients with de-novo liver nodes (LN). Methods and Materials: A total of 46 Child-Pugh A cirrhotics, mean age 65 yr, with 33 (72%) males, under US surveillance at 6-month intervals, who developed an LN, underwent CE-US, TC, MRI and fine-needle biopsy (FNB). FNB was the diagnostic gold standard. Results: A total of 48 LN were identified: 1 (2%) 1 cm, 42 (88%) 1-2 cm, 5 (10%) 2 cm; 28 (58%) HCC: 1 (4%) 1 cm, 23 (82%) 1-2 cm, 4 (14%) 2 cm; 1 (2%) cholangiocarcinoma; 17 (36%) macroregenerative nodes; 2 (4%) low-grade dysplastic nodes. Among the 1-2 cm LN, a typical vascular pattern for HCC was detected in seven (17%) by CE-US, in nine (21%) by CT and in nine (21%) by MRI, all showing absolute specificity for HCC. Among the 1-2 cm HCC, a typical vascular pattern was detected at least one imaging technique in 14 (61%), and a coincidental typical vascular pattern at two techniques (AASLD criteria) in 9 (39%). Among the 1-2 cm LN, sensitivity and NPV were 30 and 54% for CE-US, 39 and 58% for CT, 41 and 59% for MRI, with specificity and PPV for all the techniques. Conclusion: The study validates the AASLD guidelines for HCC diagnosis in cirrhotic patients. One single contrast imaging technique may be enough to diagnose HCC not only in 2 cm nodes, but also within 1-2 cm diameter. B-100 11:51 Hepatocellular carcinoma associated with Budd-Chiari syndrome B.-K. Kang, D.-I. Gwon, G.-Y. Ko, K.-B. Sung, H.-K. Yoon, J.-H. Shin, J.-H. Kim, J.-M. Lee, J.-Y. Ohm; Seoul/KR ([email protected]) Purpose: To analyze the clinical and imaging features of hepatocellular carcinoma (HCC) associated with Budd-Chiari syndrome (BCS). Methods and Materials: From March 1996 to March 2008, 98 patients with BCS were retrospectively evaluated. All the patients had membranous obstruction of the inferior vena cava. Liver nodules were evaluated using serum A-fetoprotein (AFP) level and imaging features such as computed tomography (CT) and magnetic resonance imaging (MRI). The clinical, radiological and histopathological characteristics of liver nodules were analyzed. Scientific Sessions attenuations of GGNs were measured by using a commercial software. Interscan variability with theses three different reconstruction algorithms was established using the Bland and Altman method. Results: Nodule segmentation was successful in 27 (64%), 42 (100%) and 42 (100%) measurements with B30f, B50f and B60f, respectively. Low success rate of segmentation with B30 hindered further analysis of reproducibility. In terms of the volume measurements, interscan variability was -13.50 to 14.38% (mean relative difference, 0.44%), and -16.27 to 13.63% (mean relative difference, -1.32%) with B50f and B60f, respectively. With respect to attenuation measurements, interscan variability was -9.89 to 5.10% (mean relative difference, -2.3%), and -2.86% to 5.49% (mean relative difference, 1.36%) with B50f and B60f, respectively. Conclusion: With either sharp or medium sharp reconstruction algorithm, variation of volume and attenuation measurements of GGNs using commercial software is sufficiently minimal to allow the detection of their clinically relevant growth. 10:30 - 12:00 B-103 Room P Chest SS 204 Pulmonary nodule detection and evaluation Moderators: N. Karabulut; Denizli/TR A.R. Larici; Rome/IT B-101 10:30 Pulmonary nodules with or without ground-glass opacity on 64 detectorsrow CT: Performance comparison of radiologists and computer-aided detection M. Yanagawa1, O. Honda1, N. Tomiyama1, S. Yoshida1, A. Inoue1, H. Sumikawa1, T. Daimon2, T. Johkoh3, H. Nakamura1; 1Suita/JP, 2Shimotsuke/JP, 3Itami/JP ([email protected]) Purpose: To evaluate the performance of a computer-aided detection (CAD) system in the detection of lung nodules by 64-detector-row CT compared to visual interpretation. Methods and Materials: CT examinations were performed in 48 patients (16 men, 32 women; age range, 42-85 years; mean age, 62.3 years) with suspicious pulmonary nodules on chest radiographs. Three radiologists independently analyzed the CT scans, reported the location and pattern (ground-glass opacity [GGO], solid, and part-solid) of each nodule candidate, and assigned each a confidence score. All CT scans were also analyzed by these radiologists using the commercially available CAD system. A reference standard was established by a consensus panel of different radiologists, who found 229 non-calcified nodules with a diameter of 4 mm or more. True-positive and false-positive results and confidence levels were used to generate alternative free-response receiver operating characteristic (AFROC) plots. Results: The sensitivity of GGO for 3 radiologists (70, 60, and 80%, respectively) was significantly higher than that for CAD system (21%) (McNemar’s test, p 0.0001). For solid nodules, the areas under the AFROC curves (Az) without and with the CAD system were significantly different (two-tailed paired t test, p = 0.03). For GGO and part-solid nodules, the Az value with the CAD system were greater than that without the CAD system, although there were no statistically significant differences. Conclusion: Radiologists are significantly superior to this CAD system in the detection of GGO; however, the CAD system can still play a complementary role in detecting nodules with or without GGO. B-102 10:39 Persistent pulmonary ground-glass nodules: Interscan variability of semiautomated volume and attenuation measurements C. Park1, J. Goo1, H. Lee1, K. Kim2, C. Lee1; 1Seoul/KR, 2Gyeonggi-Do/KR ([email protected]) Purpose: To assess the interscan variability of semiautomated volume and attenuation measurements for pulmonary ground-glass nodules (GGNs) by using commercial volumetry software. Methods and Materials: A total of 21GGNs in 17 patients referred for known GGNs were evaluated with two consecutive non-enhanced chest CT examinations (120 kVp, 100 mAs, collimation 16 x 0.75 mm, slice thickness 1 mm). For the second limited scan including GGNs, patients got off and on the table to simulate a follow-up examination. CT images were reconstructed using three different algorithms (sharp, B60f; medium sharp, B50f; and medium smooth, B30f). Volumes and 10:48 Utility of 3D automatic exposure control for low-dose chest CT examination: Dose optimization for detection of GGO and partly solid nodule in chest phantom study K. Matsumoto, Y. Ohno, A. Kono, H. Koyama, Y. Onishi, M. Nogami, D. Takenaka, K. Sugimura; Kobe/JP Purpose: The purpose of this study was to determine the utility of 3D automatic exposure control (AEC) for radiation dose optimization in low-dose chest CT examination at 64-detector row CT system in chest phantom study. Methods and Materials: A chest CT phantom including simulated focal GGOs and partly solid nodules, whose diameters were from 2 to 14 mm, was scanned using a 64-detector row CT with and without 3D AEC. On CT scan with 3D AEC, SDs were changed from 40 to 200. All other parameters were fixed. Identification and image quality of each simulated abnormality were visually assessed by two chest radiologists with a five-point scoring system. Interobserver agreements were assessed by kappa analysis. Then, identification and image quality of each SD were compared with that of a fixed tube current by ROC analysis and ANOVA. Results: All interobserver agreements were substantial (kappa 0.61). When SDs more than 160 were adopted, Azs of CT scan with 3D AEC was significantly lower than that without 3D AEC (P 0.05). When SDs more than 100 were adopted, the image quality of CT scan with 3D AEC was significantly lower than that without 3D AEC (P 0.05). The lowest radiation doses of CT scan with 3D AEC were determined as 2.59 mSv for identification (SD = 160) and 4.89 mSv for image quality (SD = 100). Conclusion: 3D-AEC is useful for radiation dose optimization in low-dose chest CT examination, and is able to achieve at least 50% dose reduction without significant degradation of image quality as compared with routine clinical protocol. B-104 10:57 Volumetric measurement of pulmonary nodules at low dose chest CT: Effect of section thickness and reconstruction kernel on measurement variability Y. Wang1, G.H. De Bock1, R.J. van Klaveren2, W.G.J. Tukker1, Y. Zhao1, M.D. Dorrius1, R. Vliegenthart ProenГ§a1, P.M.A. van Ooijen1, M. Oudkerk1; 1 Groningen/NL, 2Rotterdam/NL ([email protected]) Purpose: To assess the volumetric measurement variability in pulmonary nodules detected at low-dose chest CT scans using different section thicknesses and reconstruction kernels. Methods and Materials: Two hundred small pulmonary nodules identified on 79 low-dose chest CT scans from a lung cancer screening project were selected for volumetric analysis. All CT data were reconstructed in three different settings with combination of section thickness and reconstruction kernel: 1 mm & soft kernel, 2 mm & soft kernel, 2 mm & sharp kernel. All nodules were measured three times with LungCareВ® software by one radiologist in each setting. The variability of each setting was assessed with repeatability coefficients, which were calculated using the Bland and Altman method. The variability between settings was assessed with relative volume difference (RVD). Univariate analysis was applied to test the impact of nodule characteristics on variability between settings. Results: The repeatability coefficients were 8.6, 19.3, and 31.9% for 1 mm & soft kernel, 2 mm & soft kernel and 2 mm & sharp kernel, respectively. The mean RVD was 21 p 20% between 1 vs 2 mm and -20 p 21% between soft kernel and sharp kernel. Size had a significant impact on RVD between settings (p 0.05). Conclusion: Low-dose CT reconstructed with 1 mm section thickness and soft kernel provided most repeatable volume measurement. Section thickness and reconstruction kernel resulted in significant differences in volume measurements, especially in small nodules. A B C D E F G H S163 Friday Results: Liver nodules were found in 37 patients, 23 of whom had HCC and the incidence of HCC associated with BCS was 23.5%. Mean age was 48 p 13 years on diagnosis of BCS, and 49 p 11.6 years on diagnosis of HCC. Increased serum AFP level had a high accuracy in distinguishing HCC from benign nodules. HCC showed a female predominance (P = 0.004). The type of HCC was single nodular in 16 (70%) and multinodular in the remaining 7 (30%) patients. Subcapsular or exophytic location was documented on all patients, whereas multiple HCCs in three patients showed intraparenchymal location. Two HCC patients had portal vein invasion, whereas no HCC patients showed bile duct invasion at the time of diagnosis. The histology of all three HCC samples appeared to be well differentiated. Conclusion: HCC, associated with BCS, tends to have female predominance and is of the single nodular type. Most BCS-associated HCCs are located in the subcapsular and/or exophytic region. Serum AFP appears to have a high utility for HCC screening in patients with BCS. Scientific Sessions B-105 11:06 Linear and volume measurements of pulmonary nodules at different CT dose levels: Intra- and inter-scan analysis V.C. Romano1, P.A. Hein1, P. Rogalla1, C. Klessen1, A. Lembcke1, V. Dicken2, L. Bornemann2, B. Hamm1, H.-C. Bauknecht1; 1Berlin/DE, 2Bremen/DE ([email protected]) Purpose: To compare interobserver variability of diameter and volume measurements of pulmonary nodules in intra- and inter-scan analysis using a semi-automated segmentation software on ultra-low-dose computed tomography (ULD-CT) and standard-dose CT (SD-CT) data. Methods and Materials: In 33 patients, two chest multi-slice CT (MSCT) data-sets were consecutively acquired in ultra-low-dose (5 mAs) and in standard-dose technique (75 mAs). Data were analyzed using the segmentation software OncoTREAT (MeVis, Bremen, Germany). The volume of 229 nodules was determined and the largest diameter (RECIST) were measured by two radiologists. Interobserver variability was calculated and data compared in an intra- and inter-scan analysis. Results: Median nodule diameter was 8.2 mm (range: 2.8-43.6 mm, mean: 10.8 mm). Nodule volume ranged between 0.01 and 49.1 ml. With respect to interobserver variability, the intrascan analysis was not statistically different (p 0.05) between ULD-CT and SD-CT with broader limits of agreement for relative differences of RECIST measurements (-31.0%; +27.0% mean -2.0% for SD-CT; -27.0%;+38.6%, mean 5.8% for ULD-CT) than for volume measurements (-9.4%, 8.0%, mean 0.7% for SD-CT; -13%, 13%, mean 0.0% for ULD-CT). The inter-scan analysis showed broadened 95% confidence intervals for volume measurements (-26.5%; 29.1% mean 1.3%, and -25.2%, 29.6%, mean 2.2%, respectively) but yielded in comparable limits of agreement for RECIST measurements. Conclusion: The variability of nodule volumetry after semiautomated segmentation as well as nodule size determination by RECIST appears to be independent of the acquisition dose in the CT data set. This is of importance regarding follow-up measurements of pulmonary nodules in screening trials using low-doseCT. B-106 11:15 The effect of CAD on readers with various levels of expertise, analyzing digital chest radiographs for lung nodules D. Shaham1, N. Bogot1, I. Leichter1, R. Lederman1, R. Eliahou1, A. Manevitch1, J. Stoeckel1, M. Dinesh2, M. Acharyya2; 1Jerusalem/IL, 2Bangalore/IN ([email protected]) Purpose: To evaluate the impact of a CAD-algorithm that detects lung nodules, on the performance of readers with various expertises. Methods and Materials: 76 digital chest-radiographs recruited from 3 sites were retrospectively correlated to CT by 2 independent expert readers, who identified 46 findings (39 nodules [5-30 mm], 7 masses) in 36 radiographs. Each finding was assigned a five-grade visibility-score. Three blinded-radiologists of different expertise analyzed all 76 radiographs retrospectively, without and with a prototype CAD-algorithm (Siemens) that marked suspicious findings on the images. Results: Using CAD, the resident improved the detection rate from 14 to 16 nodule cases, while ignoring 2 true CAD-marks. The thoracic radiologist (TR) improved the sensitivity from 20 to 22 nodule cases while accepting all true CAD-marks. The general radiologist (GR) ignored 4 true marks, with no change in the nodule detection rate. The resident and TR detected 5 masses without and with CAD, while the GR improved the detection rate from 4 to 5 masses. The resident detected the most visible of the nodules, with a mean visibility-score of 4.03, while the visibility-score for the GR and TR were 3.72 and 3.44, respectively. The aided reading increased the false findings by 0.29 for the resident, 0.08 for the GR and 0.38 for the TR. Conclusion: CAD increased detection sensitivity for all readers, but least influenced the GR. Both the resident and the GR failed to accept all true CAD-marks. The increase in sensitivity was associated with a higher false mark rate compared to un-aided reading. B-107 11:24 Evaluating the properties of pulmonary nodules missed by computer-aided detection (CAD) in chest X-ray imaging T. Achenbach, C. Dueber; Mainz/DE ([email protected]) Purpose: The knowledge of localizations and morphologies of pulmonary nodules that are typically missed or detected by CAD systems can help to improve the radiologists’ reading quality. This study aims to recognize the specific morphological and topographic differences of nodules detected or missed by CAD. Methods and Materials: We examined pulmonary nodules (n = 51, mean diameter 12 mm) with chest X-ray and MDCT (slice thickness 1-3 mm) as reference within 8 days (median). CAD was performed by the xLNA-system (Philips Medical Systems). Morphological description was performed as well as assessment of Hounsfield units’ S164 A B C D E F G F H histogram (mean, maximum, minimum), size, volume and localization (descriptive statistics and comparison of means, Mann-Whitney U-test). Results: xLNA detected 23 nodules (45.1%) and missed 28 (54.9%). A total of 13 nodules, which were not detected by the software could not be found by the radiologist on X-ray images even in retrospective correlation with MDCT. Excluding these nodules, xLNA detected 23 of the remaining 38 nodules (60.5%). Of the 38 nodules, 17 were classified as obvious and 21 as not obvious. The system found 13 of the 21 not obvious (61.9%). Detection rate was higher in blurred/irregular nodules (69%) than in round/sharp and denser nodules (56%). The lowest detection rate was found in the central nodules (2 of 12). Conclusion: CAD performance is less sensitive in the central areas. Missed nodules tended to be bigger, denser and more frequently of a round and sharp morphology than correctly detected nodules. Of the nodules not obvious, 61.9% were found by the CAD system suggesting a supportive function especially in vaguely visible nodules. B-108 11:33 Computer-aided pulmonary nodule detection: Performance of two CAD systems at different CT dose levels P.A. Hein, P. Rogalla, C. Klessen, A. Lembcke, V.C. Romano; Berlin/DE Purpose: To evaluate the impact of dose reduction on the performance of computer aided lung nodule detection systems (CAD) of two manufacturers by comparing respective CAD results on ultra-low-dose computed tomography (ULD-CT) and standard-dose CT (SD-CT). Methods and Materials: Multi-slice computed tomography data sets of 26 patients were retrospectively selected for CAD analysis. CT images had been consecutively acquired at 5 mAs (ULD-CT) and 75 mAs (SD-CT) with 120 kV tube voltage (1 mm slice thickness). Standard of reference was determined by three experienced readers in consensus. CAD reading algorithms (pre-commercial CAD system, Philips, Netherlands: CAD-1; NEV, Siemens, Germany: CAD-2) were applied on CT data sets. Results: Consensus reading identified 253 nodules on SD-CT and ULD-CT. Nodules ranged in diameter between 2 and 41 mm (mean diameter 4.8 mm). Detection rates were recorded with 72 and 62% (CAD-1 vs. CAD-2) for SD-CT and with 73 and 56% for ULD-CT, respectively. Median false-positive rates per patient were calculated with 6 and 5 (CAD-1 vs. CAD-2) for SD-CT and with 8 and 3, respectively for ULD-CT. After separate statistical analysis of nodules with diameters of 5 mm and more, detection rates increased to 83 and 61% for SD-CT and to 89 and 67% for ULD-CT (CAD-1 vs. CAD-2). For both CAD systems, there were no significant differences between the detection rates for standard- und ultralow-dose data sets (p 0.05). Conclusion: Dose reduction of the underlying CT scan and consecutive increased image noise did not significantly influence nodule detection performance of the tested CAD systems. B-109 11:42 Evaluation of phenotype of lung cancer using micro-computed tomography in K-ras transgenic living mice H. Cho1, S.H. Park1, Y.H. Park2, H.S. Kim1, K.-H. Yoon1, D.-Y. Yu3; 1Iksan/KR, 2 Taegu/KR, 3Taejon/KR ([email protected]) Purpose: The purpose of this study is to evaluate phenotypes of lung cancer using micro-computed tomography in two types of mK-ras transgenic living mice. Methods and Materials: mK-ras transgenic mice were generated to express mutant K-ras gene (GGT12GAT) to lung cells by the direction of surfactant protein C (SPC) promoter. There are two types of mK-ras transgenic mice according to the genetic background of the mice. One is B6mK-ras mice with C57BL/6, and the other is hbmK-ras mice with a mixed hybrid between C57BL/6 and DBA. Five hbmK-ras mice and three B6mK-ras mice underwent to perform micro-computed tomography. Three dimensional CT data set were acquired at 10 Вµm isotropic resolution. We obtained micro-CT images with one month intervals from sixth months to nine months of age and then sacrificed for histopathologic correlation. Results: The first type of mK-ras transgenic mice, hbmK-ras, was revealed to have multiple nodules of lung on 6 month-CT and the number and size of nodules were increased on 9 month-CT. On histopathology, the nodules were confirmed as adenoma and low grade adenocarcinoma. The second type of mK-ras transgenic mice, B6mK-ras, was revealed to have diffuse consolidation, ground glass opacity and nodules of lung on micro-CT. On histopathology, numerous alveolar type 2 cells and macrophages were accumulated in the alveolar space of the lung and the nodules were confirmed as adenomas. Conclusion: Micro-computed tomography could evaluate phenotypes of lung cancer model in mK-ras transgenic mice. Scientific Sessions B-110 11:51 Purpose: Lung cancer screening trials may provide information about cardiovascular risk. It is not yet clear whether coronary scores from non-gated scans or aortic scores are more suited for this purpose. We examined whether risk stratification based on aortic calcifications places patients into similar groups as risk based on coronary calcium scores derived from non-gated lung cancer screening studies. Methods and Materials: We included 1,091 baseline scans from subjects participating in a lung cancer screening trial (NELSON). Scans had been acquired at two centers using 16 x 0.75 mm collimation and a low-dose, non-contrast, non-ECGgated scanning protocol. To control image noise, 3-mm sections were reconstructed every 1.4 mm. Aortic and coronary calcifications were scored by two observers (130 HU threshold). For coronary calcifications four atherosclerotic risk categories were defined based on Agatston score (b10, 11-100, 101-400, 400). Since no categorization is available for aortic scores we assigned four categories, each containing the same number of subjects as the respective coronary categories. To assess the agreement, we calculated linearly weighted kappa statistics (categories) and Spearman rank correlation coefficients (scores). Results: The number of subjects was 327, 156, 175 and 433 in the four coronary risk categories, respectively. The aortic calcium score assigned 526 (48%) subjects to the same risk category as the coronary score. Linearly weighted kappa statistic was 0.37, and Spearman rank correlation between scores was 0.51. Conclusion: While yielding similar results, aortic and coronary calcium scores cannot be used interchangeably for assessing individual arteriosclerotic risk from lung cancer screening studies. 10:30 - 12:00 Room Q Interventional Radiology SS 209 Upper body interventions Moderators: R.W. GГјnther; Aachen/DE M. Rupreht; Maribor/SI B-111 10:30 Laser ablation of lung metastases: Differences in survival according to tumor entity C. Rosenberg, K. Bock, N. Hosten; Greifswald/DE ([email protected]) Purpose: The aim of the study was the measuring of survival after laser ablation of lung metastases from different primary entities. Results were supposed to provide a patient- and disease-specific outcome evaluation for laser-induced thermal ablation as a complimentary modality in multimodal cancer therapy. Methods and Materials: 64 patients underwent CT-guided laser ablative therapy of pulmonary metastases using a miniaturized internally cooled applicator system (Monocath, Trumpf Medizinsysteme, Umkirch, Germany). 20 patients suffered from colorectal, 10 from renal cell carcinoma, 6 from melanoma, 4 from breast carcinoma metastasis. Diverse entities accounted for metastatic disease in 24 other cases. Kaplan-Meier analysis was performed. Results: Median time to death was 12.2 months in all 64 cases, 24.3 months in the group of patients suffering from renal cell carcinoma and 33.6 months for colorectal carcinoma metastasis. No therapy-related deaths occurred in 129 procedures. Pneumothorax drainage was needed in 5% (7/129) of the cases. Parenchymal bleeding (13%, 17/129) always was self-limited. A median recurrence-free interval of 10.9 months could be achieved for patients with colorectal metastasis. Conclusion: Entity of the primary tumor causing pulmonary metastasis influences prognosis and outcome after image-guided laser ablative therapy. Analogously to the surgical experience performing local resection of secondary lung malignancies, best results could be achieved colorectal metastasis. Long-term outcome and postinterventional survival do not necessarily correlate with the disease-specific primary effectiveness rate. B-112 10:39 Direct temperature measurements in an ex-vivo human lung model during thermal ablation F. Koch1, A. Vietze1, S. Fillmer1, C. Hoffmann1, U. Laskowski2, A. Linder2, N. Hosten1; 1Greifswald/DE, 2Hemer/DE ([email protected]) Purpose: To evaluate whether temperature measurements during laser ablation and vital staining can provide information useful for planning treatment parameters in patients. Methods and Materials: A total of 39 tumor-bearing lung lobes (non-small cell lung cancer) were connected to an isolated human lung perfusion model immediately after surgery. This is an ex-vivo model that allows maintaining near-physiological conditions (pH, PO2, pCO2, etc). for 5-7 hours by manipulating perfusion and ventilation. During this time period, a laser ablation was performed and the increases in temperature induced by one or two laser fibers with diffuser tip were measured invasively. These data were then compared with results of 2.3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin staining. Results: Individual temperature curves varied widely. A temperature of 60 В°C was reached in the tissue between two applicators after 5 min; towards the periphery, at distances of 10 and 20 mm from the applicators, this temperature was reached after 20 and 24 min, respectively. With one applicator, 60 В°C was only surpassed at 10 mm distance. The mean diameter of the necrotic tissue on TTC stains was between 35 and 50 mm, larger than that seen macroscopically. Conclusion: Interindividual variation was high, indicating the need for monitoring parameters other than ablation time. Temperatures expected to be ablative were induced by thermal ablation in an ex-vivo lung tumor model. Simultaneous treatment with multiple applicators significantly increased the efficacy. Necrosis was seen in areas where the maximum temperature was below 60 В°C. Phenomena other than direct thermal destruction must be responsible for cell death in this zone. B-113 10:48 CT volumetric assessment of pulmonary neoplasms following radiofrequency ablation: When to consider a second interference N.-E.A. Nour-Eldin, T. Lehnert, N.N.N. Naguib, H. Korkusuz, R. Hammerstingl, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: To identify the earliest CT follow-up period to judge the success or failure of radiofrequency ablation of lung tumors and therefore to consider the time of re-ablation. Methods and Materials: Institutional ethical committee board approval was obtained, with informed consent from all patients. This retrospective study included 60 ablation sessions for 6 primary and 54 metastatic lung tumors in 44 patients (32 males, 12 females; mean age 58.9 years, SD: 15.1). Both unipolar and bipolar radiofrequency systems were used. Thin-section CT scanning with volumetric measurement of lesions was performed immediately before ablation as a control study and at regular post ablation intervals including 24 hours, 3-6 weeks and 3, 6, 9 and 12 months. Volume measurements of lesions were calculated by two radiologists in consensus using formula for ellipsoid volumes. Results: The preablation tumor volume ranges from 0.26 to 5.29 cmВі (mean 1.75 cmВі, SD 1.59). Statistical correlation between the 12-month post ablation period volume and the other follow-up periods were used. Nonsignificant (Spearman R = 0.06) and weak correlation (R = 0.44) values were detected between the post ablation tumor volume in 24 h and the 3-6 weeks periods with the 12-month period, respectively. The 3-month period showed the earliest strong correlation (R = 0.72) with the 12-month period. The 6-month period and 9-month period revealed stronger correlation with the end result (R = 0.86 and 0.93, respectively). Conclusion: The earliest follow-up period that can predict the one year end result of ablation is 3 months and earlier periods do not adequately reflect long-term results. B-114 10:57 Single-center experience in radiofrequency ablation of lung malignancies: Complications and side effects L. Crocetti, R. Cioni, E. Bozzi, C. Bartolozzi; Pisa/IT ([email protected]) Purpose: To determine major and minor complications and side effects of radiofrequency ablation (RFA) of lung malignancies and evaluate prognostic factors for the development of complications. Methods and Materials: All patients treated in a single center with RFA for lung malignancies were entered into a prospective database. Major and minor complications and side effects were reported on a per-session basis. Results: One hundred and sixty RFA procedures were performed in 114 patients with 137 malignant lung tumors. Tumor size ranged 0.7-7 cm (mean 2.3 cm p1.0). CT-guided RFA was performed under conscious sedation by using 150-200 W A B C D E F G H S165 Friday Cardiovascular risk assessment in lung cancer screening scans: Do coronary and aortic calcium scores yield comparable risks for individual subjects? I. Isgum1, P.C.A. Jacobs1, M. Gondrie1, B. van Ginneken1, M. Oudkerk2, W.P.T.M. Mali1, Y. van der Graaf1, M. Prokop1; 1Utrecht/NL, 2Groningen/NL ([email protected]) Scientific Sessions generators and multitined expandable electrodes (RITA Medical Systems). One procedure-related death occurred. Major complications were observed in 13/160 procedures: eleven occurred during or immediately after the procedure (pneumothorax requiring drainage, n=8, and hemothorax treated conservatively, n=3) and two occurred during the periprocedural time (a pneumomediastinum associated with subcutaneous emphysema and a pneumothorax requiring surgery). Minor complications were observed in 29/160 procedures (pneumothorax and pleural effusion not requiring drainage). Side effects were encountered in 51/160 procedures (pain, limited intraparenchymal hemorrhage, lesion cavitation with bronchial drainage). Conclusion: Percutaneous RFA of lung malignancies is associated with a low risk of complications. Lesion size was the only statistically significant prognostic factor for the development of complications. The procedure-specific major complication rate is below 10% in experienced hands. B-115 11:06 Is it possible to predict the end result of radiofrequency ablated lung tumors by using contrast enhanced MRI follow-up? N.-E.A. Nour-Eldin, N.N.N. Naguib, T. Lehnert, H. Korkusuz, S. Zangos, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: To determine the effectiveness of contrast enhanced MRI (CE-MRI) lesion marginal signal intensity to paraspinal signal intensity ratio in the determination of end result of radiofrequency ablation of pulmonary neoplasms. Methods and Materials: This retrospective study included 60 ablation sessions for lung tumors in 44 patients (32 males,12 females; mean age 58.9 y). CE-MRI scanning of pulmonary tumors was performed 1 week before ablation (as a control study) and in the post ablation follow-up on 24 h, 3-6 weeks, 3 months, 6 months, 9 months and 12 months. The lesion marginal enhancement signal intensity to paraspinal muscle signal (LMS) ratio was measured using T1 Fast Low Angle Shot 2 Dimensional (FLASH-2D) trans-axial breath holding sequence, using 1.5 Tesla MRI unit as a parameter of assessment. Thin-section CT scanning with volumetric measurement of lesions was performed at the same time periods. The correlation between the LMS ratio at each follow-up period with the 12 month end result post ablation follow-up tumor volume. Results: The preablation tumor volumes range 0.26-5.29 cm3 (mean 1.75 cmВі, SD1.59), while 12 month post ablation tumor volume range 0.06-21.5 cm3. Weak correlation was detected between the LMS ratios and 12 month CT volumetric result in 24 h post ablation and 3-6 weeks (Spearman R:0.1, p=0.64 and R:0.2, p=0.08, respectively). A strong correlation between the LMS ratios and the 12 month end result CT tumor volume on the follow-up period on 3 months (R:0.63, p=0.001), 6 months (R:0.7, p=0.0002), 9 months (R:0.68, p=0.0003) and 12 months (R:0.75, p=0.0). LMS ratio 1 was associated with post ablation reduction of tumor volume, while LMS ratio 1 were associated with post ablation increase of tumor volume. Conclusion: MRI contrast enhanced lesion marginal signal intensity to paraspinal signal intensity ratio follow-up can effectively determine the tumor course post ablation. B-116 11:15 Pulmonary hemorrhage complicating radiofrequency ablation, from mild haemoptysis to life-threatening pattern N.-E.A. Nour-Eldin, S. Zangos, N.N.N. Naguib, K. Eichler, H. Korkusuz, M.G. Mack, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: To assess risk factors and extent of pulmonary hemorrhage and haemothorax complicating radiofrequency (RF) ablation of pulmonary neoplasms. Methods and Materials: Institutional ethical committee review board approval was obtained, with informed consent from the patients. This study involved 248 ablation sessions for lung tumors (20 primary lesions and 228 metastatic lesions) in 164 patients (92 males, 72 females; mean age 59.7 years) in the time period between March 2004 and January 2008. The exclusion criteria for ablation therapy were lesions with maximal diameter more than 5 cm, lesions more than five in number, bleeding tendency (prothrombin concentration less than 75%, platelets count less than 50,000/cc). Both unipolar and bipolar radiofrequency systems were used under CT guidance. Results: In our study, the incidence of intraparenchymal pulmonary haemorrhage (perilesional and in the track between the site puncture and the lesion) and pleural effusion were 19.3% (48 of 124 sessions) and 4% (8 of 124 sessions), respectively. These complications were treated conservatively with complete resolution within 3-6 weeks.Univariate analysis of contributing risk factors revealed: lesion size (P = 0.015), pathology type (P = 0.007), direct subpleural lesions (P 0.0001), technical factors necessitating excessive manipulations (including direct retrocostal lesions, small size lesions and angular application of the electrode needle) and multiple electrodes applications. S166 A B C D E F G F H Conclusion: Pulmonary haemorrhage and pleural effusion are self-limiting complications of radiofrequency ablation of lung neoplasms when precautions against risk factors are strictly followed. B-117 11:24 Prevention of pneumothorax following transthoracic needle biopsy (TTNB): Feasibility study of safety and effectiveness of a new sealant system S.G. Lindemayr1, M. Kreuter2, R. Hammerstingl1, T.J. Vogl1; 1Frankfurt a. Main/DE, 2 Heidelberg/DE ([email protected]) Purpose: To determine the safety effectiveness of a single transthoracic injection of PneuSeal sealant along the needle track in the lung parenchyma pleura for prevention of a pneumothorax (PTx) following TTNB compared to baseline historical controls. Methods and Materials: Prospective, non-randomized, historical controlled 2-center-study. 38 patients underwent TTNB of the lung, followed by injection along the needle track of PneuSeal (PneumRx, Mountain View, CA). Chest radiograph CT was used to detect PTx within 3 14 days post biopsy. Hemoptysis and change from baseline spirometry clinical status were recorded. Mean age was 65.6 (38-79) years. Mean lesion diameter was 3.2 cm (range: 0.5 8.6 cm), mean lesion depth was 1.4 cm (range: 0-4.3 cm). Results: 1/38 (2.6%) required chest venting. 1 patient (pt) experienced parenchymal bleed pre-sealant injection, which stopped post-injection. 1 pt suffered hemoptysis pre-injection, with no additional pts experiencing hemoptysis, post-injection. 11/38 (29%) experienced a small PTx (range: 0.3 1.9 cm) post-sealant injection, 2/38 (5.3%) had medium PTx (1-2 cm) 0/38 (0%) had large ( 2 cm) PTx. This favorably compares to historical data: of 8.3% small PTx, 8.3% medium PTx 5.6% large PTx. Historical chest venting rate is 5.6%. All pts tolerated the sealant without SAEs. No inflammatory reactions or changes in mean FEV1-values were found after treatment. 1 pt experienced significant pain during the procedure for unknown reason. Conclusion: Injection of PneuSeal appears to reduce the rate of significant PTx chest tube placement and appears safe well tolerated. Multicenter studies are ongoing. B-118 11:33 Percutaneous treatment of massive pulmonary embolism: Mechanical fragmentation and fibrinolysis S. Pieri, P. Agresti; Rome/IT ([email protected]) Purpose: Massive pulmonary embolism is a severe clinical condition that requires prompt therapeutic intervention. We report our experience with a hybrid treatment involving systematic fragmentation of the embolus with an angiographic catheter associated with fibrinolytic therapy over the following days. Methods and Materials: From 1999 to 2005, we treated 172 patients with massive pulmonary embolism. We used the same angiographic catheter for mechanical fragmentation and for administration of the fibrinolytic agent (24-72 h). Results were assessed on the basis of changes in mean pulmonary artery pressure. Results: After fragmentation with the angiographic catheter, we observed four types of haemodynamic behaviour: in 69 patients (41.4%), mean pulmonary artery pressure fell rapidly below 30 mmHg; in 39 patients (23.1%), two passes were required to achieve the same result; in 32 patients (19.5%) three passes were required. In the remaining 26 patients (15.8%), at no time did the mean pulmonary artery pressure fall below 35 mmHg. The only two deaths occurred in this last group. Conclusion: Mechanical fragmentation with the angiographic catheter and administration of fibrinolytic agents effectively brought about a rapid improvement in patients’ clinical status by moving the embolus towards the periphery. B-119 11:42 In vivo radio frequency ablation (RFA) in small breast cancer: Preliminairy results B.G. Looij1, D.L. Kreb2, J.C. van der Linden1, M.F. Ernst1, J.F.M. Pruijt1, K. Bosscha1, G.J. Jager1, M.J.C.M. Rutten1; 1's-Hertogenbosch/NL, 2Utrecht/NL ([email protected]) Purpose: Radiofrequency ablation may be an effective alternative treatment option for breast cancer patients unsuitable/unfit for surgery. This study was designed to assess the feasibility, efficacy and safety of radio frequency ablation (RFA) in small breast cancer. Methods and Materials: Eight patients with solitary small (< 1,5 cm) breast cancer were included. All tumors were invasive ductal carcinoma. RFA was performed under general anaesthesia followed by lumpectomy or mastectomy. A 17-gauge Cool-Tip RF needle was placed in the centre of the tumor using real-time ultrasound guidance. The tumor was ablated for 12 minutes. Whole mount sectioning of the Scientific Sessions B-120 11:51 Clinical efficacy of percutaneous ethanol injection of hypervascular cold nodules of the thyroid L. Tarantino1, I. Sordelli2, A. De Rosa2, F. Esposito2, M. Perrotta1, C. Ripa2, A. Villanacci3, D. Parmeggiani3, P. Sperlongano2; 1Frattamaggiore/IT, 2Naples/IT, 3 Rome/IT ([email protected]) Purpose: Efficacy of percutaneous ethanol injection (PEI) as a technique for reducing neck swelling and subjective symptoms due to cold thyroid nodules. Methods and Materials: 42 patients (36 females, 6 males; age 16 - 66 years) with a single or multiple cold nodules of the thyroid (volume range 13 - 90 ml; mean: 23 ml), showing hypervascularity at color-doppler US, underwent ultrasound guided PEI. 25/42 (59%) of the patients complained the following symptoms: sensation of airway obstruction difficult swallowing pain. All nodules underwent echo guided fine needle biopsy (3 passages for nodule) to rule out malignancy. Effectiveness of PEI was evaluated with color-power-Doppler follow-up and assessment of patients’ satisfaction by a questionnaire. Results: Fine needle biopsy excluded malignancy in all cases. We performed 2-11 sessions of PEI per patients with injection of 3 - 14 ml of ethanol per session (total amount per patient: 17 - 120 ml). During the follow-up ranging 12 - 44 months (median: 26 months), all nodules showed a marked decrease of the pretreatment volume (50 - 95%). 6 - 12 months after the treatment, 29 patients showed a normal neck shape and the other 13 patients referred the aesthetical results as very “satisfying”. 21/25 (84%) of symptomatic patients referred complete disappearance of subjective symptoms. No complication was reported. Conclusion: PEI seems to be an effective and safe therapy for treatment in patients with neck swelling and symptoms due to cold nodules of the thyroid. 10:30 - 12:00 Room R Cardiac SS 203 Coronary CT angiography: Reconstruction algorithms and dose reduction Moderators: D. Fleischmann; Stanford, CA/US R. Marano; Rome/IT B-121 10:30 Biological X-ray effects in coronary CT angiography: Comparison of helical with sequential scan modes M.A. Kuefner, S.A. Schwab, S. Azoulay, K. Anders, S. Achenbach, W. Bautz, M. LГ¶brich, M. Uder; Erlangen/DE ([email protected]) Purpose: Sequential scan modes should lead to a reduction of physical dose in coronary CT angiography (CTA) compared to helical scans. The established physical dose parameters determine exposition, but do not assess biological X-ray interactions. Determination of DNA double-strand breaks (DSBs) provides an accurate estimate of biological radiation effects. Therefore, it was our aim to compare in-vivo DNA lesions introduced during helical with sequential CTA. Methods and Materials: 31 patients were examined with various scan protocols using a 64-slice dual-source (helical scan: 100-120 kV, 330-438 mAs/rot, pitch 0.2-0.39, ECG-modulated tube current) or a 128-slice single-source CT scanner (sequential scan: 120 kV, 150-300 mA, table feed 34.5 mm). Blood lymphocytes were isolated, stained against the phosphorylated histone variant YH2 AX, and DSBs were visualised using fluorescence microscopy. Results: Dose length product (DLP) ranged from 155 to 402 (mean 249 mGy*cm) in sequential and from 508 to 1700 mGy*cm (mean 958 mGy*cm) in spiral scans (p=0.00003). Mean number of DSBs 30 minutes after CTA ranged from 0.11 to 0.71 per cell and was significantly lower after sequential (0.14 DSBs/cell) compared to helical scans (0.39 DSBs/cell, p=0.0005). Number of DSBs showed a correlation to DLP (R=0.73). Using a helical scan mode a 100 kV protocol led to a reduction (p 0.05) whereas additional calcium scoring led to a significant elevation of DSB levels (p=0.04). Conclusion: A sequential coronary CTA can lead to a significant reduction of DLP and X-ray induced DNA damages compared to helical scans. B-122 10:39 Biological dose estimation in coronary angiography by determination of X-ray induced DNA double-strand breaks S.A. Schwab1, M.A. Kuefner1, S. Brunner1, S. Azoulay1, C.D. Garlichs1, W. Bautz1, M. Loebrich2, M. Uder1; 1Erlangen/DE, 2Darmstadt/DE ([email protected]) Purpose: During coronary angiography patients are exposed to rather high X-ray doses and interventional cardiologists to scattered radiation. Physical dose parameters can determine exposition, but do not adequately evaluate dose deposition in the patient. DNA double-strand breaks (DSBs) are among the most significant genetic lesions introduced by ionising radiation. The aim of this study was to assess radiation induced DSBs and to estimate biological dose in patients and cardiologists after angiography. Methods and Materials: Blood samples were taken from 37 patients undergoing coronary angiography and from 3 interventional cardiologists before and after the examinations. DSBs were visualised using immunofluorescence microscopy after staining against the phosphorylated histone variant gamma-H2 AX. Radiation dose to the blood was estimated by relating in-vivo number of DSBs to those of individual in-vitro irradiated samples (50 mGy). Results: Dose area product (DAP) ranged from 1337 to 12448 ВµGy*m2, fluoroscopy time ranged from 1.5 to 14.4 minutes. In all patients, an irradiation induced increase of DSBs was detected. Number of DSBs at the end of fluoroscopy ranged from 0.49 to 1.08 per cell, thereafter a rapid loss of foci was observed. Radiation dose to the blood ranged from 23.4 to 56.4 mGy. In cardiologists, no significant increase of DSBs during a working day was found. Conclusion: Gamma-H2 AX immunofluorescence microscopy is suitable for biological dose estimation in coronary angiography. High damage levels were found in patients, whereas after a working day in interventional cardiologists no biological X-ray effects due to scattered irradiation could be detected. B-123 10:48 Coronary artery calcium quantification based on virtual non-contrast enhanced dual energy CT coronary angiography F. Schwarz, G. Bastarrika, B. Ruzsics, A. Sterzik, R. Brothers, P. Costello, U.J. Schoepf; Charleston, SC/US ([email protected]) Purpose: Coronary CT angiography (CCTA) is often performed in conjunction with non-contrast coronary artery calcium scoring. We aimed to investigate whether coronary calcium can be quantified based on virtual non-contrast reconstructions obtained from contrast-enhanced dual energy CCTA. Methods and Materials: With IRB approval, 25 patients (18 male, mean age 60.4p11.2 years, mean heart-rate 60.9p11.5 bpm) underwent conventional noncontrast coronary calcium scoring followed by contrast-enhanced CCTA performed in dual energy mode (A-tube: 140 kV, B-tube: 100 kV). From the dual energy CCTA data, 3 mm sections of both energy spectra were reconstructed. Virtual non-contrast series were generated using commercially available software (Syngo-Dual-Energy, Siemens). Image series were analyzed in random order by two blinded, independent observers who performed calcium quantification on both, conventional calcium scoring scans and virtual non-contrast reconstructions. Results were used to generate a regression model correlating the Agatston scores obtained with both methods. Results: Mean Agatston scores from virtual non-contrast enhanced reconstructions were systematically lower (mean 181p402) than from conventional non-contrast scans (mean 555p843). After log-transformation virtual and conventional scores followed normal distribution and showed excellent linear regression (R=0.94, p 0.001). Predicted Agatston scores using this regression model and conventional Agatston scores demonstrated excellent linear correlation (R=0.90, p 0.0001, n=25) and agreement (CCC=0.85 [0.73-0.92]). Conclusion: There is excellent correlation between coronary calcium scores based on virtual non-contrast reconstructions from dual energy CCTA data and conventional calcium scoring. Therefore, this approach may have potential to quantify coronary artery calcium and assess coronary artery anatomy with a single dual energy CCTA scan without the need for a prior non-contrast calcium scoring scan. A B C D E F G H S167 Friday ablated region was performed and the specimens were stained with cytokeratine 8 (C-8) method to assess tumor cell viability. Results: Mean patient age was 67 years (range 56-77). All procedures were technically successful. A median end temperature of 65В°C (range 55В°-80В°) was reached. At histopathological examination the diameter of the ablated region ranged from 23 to 44 mm (mean 30) and the mean tumor size was 14 mm (range 8-24). C-8 staining revealed complete cell death in all 8 lesions. One procedure was complicated by a superficial skin burn as a result of heat conducting to the skin along a metal localisation wire. Conclusion: (1) US guided RFA can result in complete cell death in small breast cancer. (2) US guided RFA in small breast cancer is a safe procedure but can lead to superficial skin burn. Scientific Sessions B-124 10:57 320-slice computed tomography using minimal amount of contrast material and low radiation dose: Feasibility and resulting image quality A. Lembcke, P. Hein, M. Wagner, C. Kloeters, B. Hamm, P. Rogalla; Berlin/DE ([email protected]) Purpose: To establish a scanning protocol and to evaluate the resulting image quality in 320-slice cardiac CT with 35 ml of contrast material and low radiation exposure. Methods and Materials: 24 patients (16 males, 36-74 years, body mass index 18-26, heart rate 54-69/min) were scanned with array detector CT (320 detector rows, AquilionOne, Toshiba) at 100 kV, 300-450 mA, 0.5 mm collimation with 0.25 reconstruction increment, 350 ms rotation time. A single beat acquisition with punctual exposure at 75% of the RR-interval was performed following intravenous administration of 35 ml iodinated contrast material at a flow rate of 7.5 ml/s. Scanning was initiated using real-time bolus tracking. Vessel attenuation, image noise and contrast-to-noise ratio were measured and the overall image quality and diagnostic confidence was rated. Results: All scans had diagnostic quality. Attenuation values (density in the aortic root) ranged between 312 and 523 HU, image noise (standard deviation in aortic root) ranged from 28 to 56 HU and respective contrast-to-noise ratio ranged from 7.8 to 16.3. All data sets were rated to have good (n = 14) or excellent image quality (n = 10)) and diagnostic confidence was rated as high (n = 11) or very high (n = 13). Calculated radiation dose (based an the displayed dose-length-product) ranged between 1.3 and 2.2 mSv. Conclusion: 320-slice CT offers the possibility to dramatically reduce radiation dose in cardiac CT. At the same time, the amount of contrast material can be reduced, mainly due to the snapshot like data acquisition. B-125 11:06 Effective patient radiation doses and skin organ doses at coronary CT angiography and invasive coronary angiography A. Sterzik, J. Abro, U.J. Schoepf, W. Huda; Charleston, SC/US ([email protected]) Purpose: To compare overall effective patient radiation doses and skin doses at coronary CT angiography (cCTA) with those at invasive coronary angiography (ICA). Methods and Materials: A total of 104 consecutive patients underwent cCTA on a 64-slice CT scanner. Effective radiation dose was quantified using the Dose Length Product (DLP). Average skin organ dose was quantified using the volume Computed Tomography Dose Index (CTDIvol). A total of 102 different consecutive patients underwent ICA. Data were obtained pertaining to a reference dose 15 cm from the isocenter and to the number of runs, fluoroscopy time and Kerma-Area Product (KAP). Results: Mean DLP for cCTA was 1,120 p 200 mGy-cm with an average effective dose equivalent to 21 mSv. For ICA, the mean number of imaging runs was 12.2 p 7.6 and the mean fluoroscopy time was 9.9 p 11.5 min. Average KAP was 84.1 p 83.7 Gy-cm2 with an average effective dose equivalent to 15 mSv. The median CTDIvol was 58 mGy with 10th and 90th percentiles at 58 and 69 mGy, respectively. For cCTA, the skin dose is approximately 2.5 times higher than CTDIvol and the average skin dose is thus estimated at ~150 mGy. For ICA, the average reference point dose was 1,420 p 1,440 mGy. The median reference point dose was 960 mGy with 10th and 90th percentiles at 300 and 2,940 mGy, respectively. Conclusion: Average effective patient radiation doses at cCTA are somewhat higher than those of ICA, but the latter show much more variation between patients. Average skin doses at ICA are an order of magnitude higher than those associated with cCTA and may exceed the threshold dose (2,000 mGy) for inducing skin damage. B-126 11:15 Lower radiation dose with 320 MDCT volume coronary angiography using prospective ECG gating (pECG) J. Hoe; Singapore/SG ([email protected]) Purpose: To determine radiation dose using 320MDCT volume scanning, which can be performed using pECG. Methods and Materials: 201 patients were scanned using 100 or 120 kVp tube voltage. Radiation dose was measured as extended dose length product (DLPe) and estimated effective dose (mSv) calculated. DLPe not DLP is used because of 16 cm scan coverage with 320MDCT. For heart rates (HR) 65 bpm, exposure phase was 65% till end of R wave of cardiac cycle, using a one heart beat (HB) acquisition. For HR 66-85 bpm scanning used a 2 or 3 HB scan. Results: For one HB acquisition, with HR 65 bpm and with no arrhythmias, the mean effective dose was 6.9 mSv p2.0 mSv (lowest dose was 1.9 mSv). The per- S168 A B C D E F G F H centage reduction in effective dose (difference between predicted DLP and DLPe using pECG) was -51p11%. Qualitative image quality was also assessed to be in good to excellent range while uniform image quality was assessed to be in low to medium mottle range. Mean estimated radiation dose for patients scanned using 2 or 3 HB scans was 18.5 mSv. Conclusion: pECG scanning using 320MDCT, in patients with HR 65 bpm, results in significantly lower radiation compared with conventional 64MDCT and similar doses to 64MDCT with step and shoot scanning using padding. Heart rate reduction using betablockers is necessary to ensure one HB scan to achieve the lower radiation dose. Further reduction in dose can likely be achieved by narrowing the exposure phase currently being used with also more consistent use of lower tube voltages e.g. 80 & 100 kVp. B-127 11:24 Impact of heart rate on radiation dose in ECG-gated dual-source-CT coronary angiography P. Blanke, U. Saueressig, G. Pache, T. Bley, E. Kotter, M. Langer; Freiburg/DE ([email protected]) Purpose: Dual source CT (DSCT) scanners allow for an increase in pitch with increasing heart rates. The effect of increasing heart rate on the dose performance of DSCT coronary angiography was investigated. Methods and Materials: 95 consecutive patients underwent retrospectively gated DSCT coronary angiography (Siemens Definiton) with ECG controlled pulsing windows with reduced systolic tube current and automatic pitch adaption (120 kV, 2 x 350 mAs maximum tube current, minimal tube current 4% of maximum outside the pulsing window). Depending on heart rate, two different pulsing windows were employed: a narrow window around 70% of RR cycle in patients with heart rates below 75 bpm (n=52), or a wider window between 35 to 70% of RR cycle for heart rates between 75 and 90 bpm (n=43). CTDI, DLP, and effective dose were compared between both groups. Diagnostic quality of the images was assessed on a per segment basis. Results: Radiation dose exposure was significantly higher in the group with the wider pulsing window compared to the narrow pulsing window; CTDI 42.6 p 9.3 vs. 31.5 p 8.7 mGy; effective dose 11.1 p 3.3 vs. 7.9 p 2.6 mSv, p 0.001. Both systolic and diastolic reconstructions were needed for diagnostic assessment in the group with the wider pulsing window. Conclusion: The dose increment caused by a wider pulsing window at higher heart rates seems to override the dose saving effect of higher pitch values leading to an overall higher radiation dose in patients with higher heart rates. B-128 11:33 Quantification of radiation dose savings in cardiac-computed tomography using prospectively triggered scan mode and ECG pulsing: A phantom study L. Lehmkuhl1, D. Gosch1, H.-D. Nagel2, T. Kahn1, M. Gutberlet1; 1Leipzig/DE, 2 Hamburg/DE ([email protected]) Purpose: The aim of this phantom study was to quantify radiation dose reduction in cardiac computed tomography (CT) using a prospectively triggered scan mode (“step-and-shoot”) in comparison to a retrospectively ECG-gated helical scan mode. Methods and Materials: Absorbed organ doses in cardiac CT scans (64-row) were quantified using an anthropomorphic male Alderson phantom. A total of 74 thermoluminescence dosimeters (TLD) were placed into the phantom (63) and on its surface (11). Three different scan protocols were applied, and each measurement was performed three times. Protocol 1: retrospectively ECG-gated mode (800 mAs;120 kV; scan length = 12.4 cm; pitch = 0.2; rotation = 0.4 sec) as used in clinical routine. Protocol 2: similar to protocol 1 using additional ECG pulsing of the tube current with dose maximum at 75% of the R-R interval. Protocol 3: prospectively triggered mode (“step-and-shoot”), with data acquisition at 75% (R-R). To guarantee equal image quality, image noise and mAs settings of the prospectively triggered mode were evaluated in a pre-test. Tube current was then set to 210 mAs. The scan length and tube voltage were similar to the other protocols. In all protocols, an ECG simulator was used (heart rate 60/min). Results: Compared to the retrospectively ECG-gated mode, mean relative organ doses could be reduced to about 43.8% using ECG pulsing and about 75.9% using the prospectively triggered mode, respectively. The range of dose savings varied from 33.6 to 48.6% using ECG pulsing and from 65.3% to 87.2% using step-and-shoot mode. Conclusion: TLD measurements approved the relevance of dose-saving protocols in cardiac CT. Prospectively triggered cardiac CT, with the recently introduced step-and-shoot protocol, demonstrated the best performance compared to ECG pulsing with a dose reduction of up to 87.2%. Scientific Sessions B-129 11:42 Impact of advanced reconstruction and workflow techniques on coronary CT diagnostic and productivity performance: A prospective study B. Merlino, R. Marano, A. Simeone, G. Savino, L. Natale, L. Bonomo; Rome/IT ([email protected]) B-130 11:51 The impact of high temporal resolution on low heart rates: Comparison between dual-source and 64-slice CT coronary angiography S. BaumГјller; ZГјrich/CH ([email protected]) Purpose: To compare the diagnostic performance of dual-source computed tomography (DSCT) and 64-slice CT for the assessment of significant coronary artery stenoses at low heart rates (HR). Methods and Materials: 200 patients with HR 65 bpm were enrolled in this retrospective study. Each of the 100 patients underwent dual-source and 64-slice CT coronary angiography. Each patient underwent invasive coronary angiography (ICA) within 4 weeks of CT. Two blinded observers independently assessed image quality of all coronary segments with a diameter r1.5 mm as being assessable or not, and assessed presence of significant stenoses (defined as luminal diameter narrowing of 50%) in each coronary segment. Patient-based accuracy, sensitivity, specificity, positive predictive (PPV) and negative predictive value (NPV) for the detection of significant coronary stenoses with CT were calculated using ICA as standard of reference. Results: No significant differences were found regarding gender (p=0.88), age (p=0.54), body weight (p=0.9) cardiovascular risk profile (p=0.90), mean HR (p=0.18), variability of HR (p=0.14), Agatston-score (p=0.88) between the patients in the DSCT and those in the 64-slice CT group. There was no significant difference in the rate of non-assessable coronary artery segments between 64-slice CT (1.8%, 25/1387) and DSCT (1.0%, 14/1405; p=0.08). Patient-based accuracy, sensitivity, specificity, PPV, and NPV, respectively, were as follows: 97, 96, 97, 83, 100% at DSCT and 95, 92, 95, 75, 99% at 64-slice CT. Overall accuracy (p 0.05) as well as specificity (p 0.05) were significantly higher with DSCT as compared with 64-slice CT. Conclusion: In patients with low HR, the higher temporal resolution of DSCT results in an improved diagnostic performance when compared to 64-slice CT coronary angiography. Room A Abdominal Viscera (Solid Organs) SS 301a Friday Purpose: To assess advanced 3D workstation (WS) solutions impact on workflow, diagnostic performance and productivity in coronary CT angiography. Methods and Materials: A total of 82 CT data sets (64-MDCT, VCT GE; Milwaukee, MI, USA) were randomly evaluated by 2 experienced observers using two different 3D WS system: TeraRecon, Inc Intuition (WS-A) and Advantage 4.3-GE (WS-B), according to a predefined standard assessment protocol. For each study, several parameters were recorded related to technical (load-to-record, VRT, MPR, MIP, editing, standard projection rendering times), workflow (step-by-step timing, GUI user response, recon and analysis time), diagnostic (lesion number and location, grading) and ergonomic performance (user required action-URA time). An overall 3D time and a semiquantitative user score (1-poor to 4-high) were also recorded. Results: No significant difference in accuracy was observed. Nevertheless, WS-A was slightly faster in loading and rendering data and more effective in managing progressive processing steps due to the optimized integration in the GUI environment (22% reduced time, p 0.05). URA was correspondently minimized for WS-A (30%, p 0.05). The need for radiologist to review initial recon data was also lower for WS-A, mostly due to the easiness to correct data "on-the-fly" during recon and view them even from thinner network client. Overall time from scanner to report was 23 min for WS-A, 38 min for WS-B (p 0.01). Conclusion: Fast scanner provides huge amount of data, whose management is critical for overall performance and productivity. Improvement of hardware, but especially more powerful and refined software solutions are the major determinant of coronary CT success. 14:00 - 15:30 Liver: MR diffusion and spectroscopy Moderators: G.M. Bongartz; Basle/CH M. Lewin; Paris/FR B-131 14:00 Contribution of echo planar imaging with diffusion-sensitising gradient on detection of small colorectal liver metastases M. Mignon, F. Zech, Y. MarГ©chal, J.-F. Gigot, C. Hubert, L. Annet; Brussels/BE ([email protected]) Purpose: To assess the contribution of diffusion-weighted sequence (DW-EPI) during a standard Gadolinium-enhanced magnetic resonance examination (MRE) for colorectal liver metastases (CLM) detection. Methods and Materials: Sixty-two MRE of patients surgically treated for CLM were retrospectively reviewed. The standard examination included TSE T2-weighted fat saturated, T1-weighted dual-echo and dynamic T1-weighted Gadolinium-enhanced sequences. DW-EPI (b = 20 sec/mm2) was additionally performed for all patients. Three independent observers reviewed the MRE first without and then with the additional DW-EPI sequences. The number, diameter, nature and localisation of all detected lesions were recorded. The inter-observer reproducibility was calculated. The sensitivity of MRE without and with DW-EPI was assessed considering the number and the size of the lesions. The positive predictive value was calculated. Pathological sampling was obtained for each CLM. Results: Pathological analysis recorded 150 metastases. The inter-observer reproducibility was high without (r = 0.849) and with DW-EPI (r = 0.870), with no significant difference between the two methods. The sensitivity was significantly influenced by DW-EPI (p = 0.0046) and by the number of lesions (p = 0.00083). No significant difference was found for lesions larger than one centimeter. The mean value of false positive per patient was 0.089 without DW-EPI and 0.202 with DW-EPI (p = 0.0073). Conclusion: The additional DW-EPI sequence to a standard Gadolinium-enhanced MRE improves the sensitivity for infracentimetric and numerous CLM at the cost of a decrease in the specificity. B-132 14:09 Detection and characterization of liver lesions in patients with gastrointestinal cancer with diffusion-weighted MR imaging M. Eiber, K. Holzapfel, M. Bruegel, C. Ganter, J. Gaa, E. Rummeny; Munich/DE ([email protected]) Purpose: To compare DW-MRI with multi-detector row CT (MS-CT) for lesion detection in patients with gastrointestinal cancer and to analyze DWI-MRI for lesion characterization. Methods and Materials: We evaluated 116 consecutive patients with colorectal (n = 82), gastric (n = 16) or oesophageal adenocarcinoma (n = 18) and suspected liver metastases with MRI at 1.5 T and contrast-enhanced 64-row MS-CT. For MRI, T1- and T2-weighted pulse sequences as well as DWI with respiratory-triggered single-shot echo-planar-imaging (SSEPI: TE 69 ms, SL 5 mm, b-values 50, 300 and 600 s/mm2) were employed. Images were analyzed by two experienced radiologists blinded to the clinical results. Results for lesion detection of MS-CT and DWI-MRI were compared using ROC analysis. In 60 patients, diffusion coefficients (ADCs) were calculated for lesion differentiation. Results: For lesion detection, ROC analysis showed superiority (P b 0.01) of DWI as compared to MS-CT. Especially, metastases with diameters of smaller than 1 cm were better detected with DWI-MRI as compared to MS-CT (P b 0.01). Results for differentiation showed mean ADC values of 1.24 for normal liver, while malignant tumors had ADCs of 1.04-.1.22 and benign lesions such as hemangiomas or cysts of 1.9-3.0, respectively. Furthermore, relevant therapeutic changes were made in 20 % of patients, based on DWI. Conclusion: MR imaging using DWI is more sensitive than multi-detector row CT in the detection and characterization of liver metastases from colorectal, pancreatic, esophageal or gastric cancer. Thus, it can be used for optimal treatment planning. A B C D E F G H S169 Scientific Sessions B-133 14:18 Detection of liver metastases in patients with malignant pancreatic tumors by diffusion-weighted MR imaging (DWI) A.A. Fingerle, K. Holzapfel, C. Reiser-Erkan, M. Bruegel, E.J. Rummeny, J. Gaa; Munich/DE ([email protected]) Purpose: To evaluate the usefulness of diffusion-weighted MR imaging (DWI) for the detection of liver metastases in patients with malignant pancreatic tumors compared to MDCT. Methods and Materials: In 31 patients with pancreatic masses diffusion-weighted MR imaging and MDCT of the liver were performed. For DWI, a respiratory-triggered, single-shot echo planar imaging (SSEPI) sequence was acquired (TR = d, TE = 69 ms, matrix 256 x 256, slice thickness 5 mm, GRAPPA 2, b-values 50, 300 and 600 sec/mm2) combined with navigator echo technique (PACE). Imaging results were correlated with histopathology and intraoperative US-findings. Results: In 31 patients a total of 31 focal liver lesions in MDCT (14 benign, 7 malignant, 10 unclear) and 52 in DWI (39 benign, 9 malignant, 4 unclear) were detected. In comparison to histopathology and intraoperative US-findings 33.3 % of liver metastases were detected by MDCT whereas DWI could detect 88.9 % of liver metastases. Specificity was 77.8 % for MDCT and 97.5 % for DWI. Therefore, DWI would have altered the therapeutic management in 6 of 31 patients. Conclusion: In patients with pancreatic tumors, diffusion-weighted MR imaging (DWI) performs significantly better in the detection of liver metastases than MDCT. This is of particular relevance to therapeutic management. B-134 14:27 MR imaging of focal liver lesions: Diffusion-weighted imaging versus gadoxetate-enhanced MRI. Preliminary results N. Bastati-Huber, W. Matzek, S. Baroud, C. Koelblinger, C.J. Herold, W. Schima, A. Ba-Ssalamah; Vienna/AT ([email protected]) Purpose: To compare diffusion-weighted imaging (DWI) with gadoxetate-enhanced T1w 3D GRE MR imaging for focal liver lesion (FLL) detection and characterization using consensus evaluation, histology and follow-up as reference standard. Methods and Materials: Thirty-eight patients (21 men,17 women; mean age 69.2 years) with at least one FLL (mean size 21 mm) were examined at 3 Tesla Siemens for FLL detection and characterization. DWI (b values 50, 400 and 800 sec/mm2) and dynamic gadoxetate-enhanced 3D-GRE MRI in the arterial-, portal venous and equilibrium phase as well as 20 min post-contrast in the hepatospecific phase were performed. Reference standard for diagnosis was obtained from consensus review by two observers of DW and dynamic contrast-enhanced images, pathologic data and follow-up imaging results. Apparent diffusion coefficient (ADC) was measured for FLLs identified at consensus review. DWI and gadoxetate-enhanced 3D GRE images were compared. Results: From a total of 92 FLLs (71 malignant, 21 benign), only 83 lesions could be detected on gadoxetate-enhanced MR imaging (90%) and only 78 lesions (85%) were detected on DWI at consensus review. The difference between both sequences was not statistically significant (P 0.59). However, FLL characterization was significantly better for gadoxetate-enhanced T1w 3D GRE (94.8%) than with DWI (71.8%, P 0.05). ADCs of malignant FLLs were significantly lower than those of benign FLLs (P 0.05). Conclusion: 3 Tesla MRI gadoxetate-enhanced T1w 3D GRE MR imaging is slightly better than DWI for detection and significantly superior for the characterization of FLL. B-135 14:36 Diffusion-weighted MR imaging of focal hepatic lesion on 3 T: Effect of intravenous gadoxate disodium (Gd-EOB-DTPA) J. Choi, M.-J. Kim, J. Lim, J.-Y. Choi, K. Kim; Seoul/KR ([email protected]) Purpose: To assess whether administration of gadoxate disodium (Gd-EOB-DTPA) might affect lesion conspicuity and ADC values on diffusion weighted imaging (DWI) for hepatic magnetic resonance imaging (MRI) on 3-T system. Methods and Materials: Twenty patients with 29 focal hepatic lesions (hepatocellular carcinoma 18, metastasis 6, hemangioma 5) underwent DWI on 3-T system before and after administration Gd-EOB-DTPA (0.025 mmol/kg). Non-breath hold DWI was performed with b values of 200, 400 and 800 s/mm2. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) of each lesion, and ADC values of the liver and lesion were calculated for precontrast and postcontrast images. The differences between precontrast and postcontrast data were assessed with paired t test. Results: The CNRs and ADC values of focal hepatic lesions were not significantly different before and after administration of contrast agent. Mean CNRs and ADC values of focal hepatic lesions were (46.71 p 29.72 and 1.20 p 0.40, respectively) S170 A B C D E F G F H for precontrast and (45.69 p 29.66 and 1.23 p 0.35) for postcontrast images. Mean SNRs and ADC values of the liver on precontrast images (19.34 p 7.59 and 1.23 p 0.15, respectively) were significantly lower (p 0.05) on postcontrast images (15.65 p 6.78 and 1.16 p 0.14). Conclusion: Postcontrast DWI after Gd-EOB-DTPA administration can be used as a substitute for precontrast DWI on 3-T system. B-136 14:45 Comparison of three methods for the construction of liver and spleen apparent diffusion coefficient color parametric maps T.G. Maris1, S. Gourtsoyianni1, K. Karolemeas2, N. Papanikolaou1, S.D. Yarmenitis1, N. Gourtsoyiannis1; 1Iraklion/GR, 2Athens/GR ([email protected]) Purpose: To compare three mathematical techniques for the calculation of apparent diffusion coefficient (ADC) of normal liver, liver focal lesions and normal spleen. Methods and Materials: Fifty consecutive patients underwent MRI examination of the liver and spleen, utilizing a spin-echo echo planar imaging diffusion sequence with four b-values (0, 50, 500, 1000). ADC calculated colour image maps were post-proccessingly reconstructed using (a) a commercially available, (b) a standard linear and (c) a weighted linear regression fitting model with b-values of 50, 500 and 1000. The three analytical methods (a, b, c) were compared in terms of their precision in the ADC calculations. Results: Differences amongst all ADC values were considered significant (ANOVA, p 0.01) using either methods. Post-hoc pairwise comparisons showed a better discrimination between normal liver and focal liver lesions when using method (c) (p 0.01). ADC measurements were performed with method (c) that showed a better precision (mean CV=3.6%) when compared with methods (a) and (b) (mean CV = 8.5%). CV was considered stable throughout the whole range of ADC measurements when method (c) was used (CV discrepancy = 1.13 %). Bland-Altman plots showed a 4% increment of the mean ADC values when method (c) was used and a random statistical variation within the 95% confidence intervals indicating that all three methods could be used interchangeably. Conclusion: ADC quantification of the liver and spleen may be performed with both linear and weighted regression analysis methods; however, the precision in ADC measurements is significantly improved when weighted regression analysis methods are utilized. B-137 14:54 Hepatic transit time analysis using contrast-enhanced MRI: Comparison of patients with liver metastases from colorectal cancer and healthy volunteers J. Hohmann1, C. MГјller2, A. Oldenburg2, J. Skrok2, K.-J. Wolf2, T. Albrecht2; 1 Basle/CH, 2Berlin/DE ([email protected]) Purpose: During the evolution of liver metastases, the hepatic blood supply changes in favour of the arterial fraction. HTT analysis may enable the detection of such changes. The aim of this study was to evaluate if HTT analysis with MRI can reveal differences between patients with liver metastases from colorectal cancer (patient group) and healthy volunteers (control group). Methods and Materials: A total of 20 patients (11 f, 9 m, mean age: 68 y) and 22 volunteers (9 f, 13 m, mean age: 50 y) were studied using a bolus test sequence (T1-Turbo-FLASH, Siemens Magnetom Vision 1.5 T, frame rate: 1/s). After 15 s baseline imaging, a bolus of 3.0 ml MultiHance (Bracco, Milano, Italy) followed by a 10 ml saline flash was injected and postcontrast images were acquired over 85 s. HTT were calculated as differences of the arrival times of the abdominal aorta (AA), hepatic artery (HA), portal vein (PV) and one hepatic vein (PV). Statistical evaluation included comparison of both groups and evaluation of an age dependency in the control group. Results: The patients showed significant shorter HTT values (HV-AA: 12.88 p 2.79 s versus 17.79 p 3.96 s, P = 0.02; HV-HA 10.85 p 3.06 s versus 15.71 p 3.75 s, P = 0.02) except for HV-PV HTT (6.80 p 1.40 s versus 9.23 p 3.35 s, P = 0.12). There was no significant slope of the regression line in the control group (P 0.05). Conclusion: MRI can show HTT differences due to changes in blood supply. No age dependency was found in the control group. There seems a need for more liver-specific contrast agents, which may result in longer and therefore more stable HTT. Scientific Sessions B-138 15:03 Quantification of liver fat content: Comparison of triple-echo chemicalshift gradient-echo imaging and in vivo proton MR spectroscopy B. Guiu, R. Loffroy, J.-M. Petit, S. Aho, D. Ben Salem, P. Hillon, J.-P. Cercueil, D. KrausГ©; Dijon/FR ([email protected]) B-139 15:12 MR quantitation of liver lipids after partial hepatectomy in a mouse model at a clinical 3 T system H. Ittrich, J. Heeren, J. Herkel, M. Merkel, K. Peldschus, A. Koops, U. Beisiegel, G. Adam; Hamburg/DE ([email protected]) Purpose: To compare different MR fat imaging sequences for a non-invasive in vivo measurement of liver lipid accumulation after partial hepatectomy in different mice models. Methods and Materials: In vivo MRI was performed before 6h, and 24h after partial hepatectomy (PH) in apolipoprotein E (ApoE) deficient and wildtype mice (WT, control) using a clinical 3 T scanner with a small animal solenoid coil. Four different T1w sequences were estimated: TSE, fat-saturated (fat-sat) TSE, water-saturated (wat-sat) TSE, and an in- or opposed-phase (iop) FFE. SNR was measured in liver at all time points corrected by standardized external control tubes filled with water and oil using ImageJ (NIH). Liver lipid concentrations (LLC, Вµg/mg protein) were measured at each time point after liver removal by standard laboratory methods. Differences in liver fat content after PH between both animal groups were tested for statistical significance (t test, p 0.05). Pearson's correlation coefficient (r) between SNR and fat concentrations was calculated for all sequences. Results: In vivo measurements showed time-dependent SNR changes in both groups correlating to the LLC changes after PH. LLC showed an accelerated increase in ApoE mice of 123.2 p 8.8% after 6 h and 240.0 p 25.8% after 24 h in comparison to WT mice (6 h: 39.0 p 17.1%, 24 h: 166.2 p 16.8%). R between SNR and LLC showed the best correlation for T1w wat-sat TSE (r=0.98), followed by iop FFE (r=-0.95), fat-sat TSE (r=0.84), and normal T1w TSE (r=0.75). Conclusion: Liver lipid concentrations and defects in liver lipid metabolism in preclinical small animal models can be measured and detected by non-invasive MRI at a clinical 3 T MR system. B-140 15:21 Diagnosis of rejection after liver transplantation: Use of phosphorus-31 magnetic resonance spectroscopy (31P-MRS) T. Jiang, S. Liu, X. Zheng; Shanghai/CN ([email protected]) Purpose: To delineate 31P-MRS abnormalities in patients with chronic rejection and to characterize spectral changes by pathology. Methods and Materials: 66 liver transplant recipients (18 with chronic rejection and 48 with normal graft function) and 38 controls (23 healthy volunteers and fifteen patients with biliary duct stricture) were studied with in vivo 31P-MRS. Results: (a) The mean value of PME/B-ATP ratio of the rejection group was 1.15p0.07 and 95% confidence interval (CI) was 1.08-1.16 vs 0.84p0.09 and 0.81-0.87 of the normal liver trans-plantation group. According to the results of ROC curve fitting, given the threshold 1.01, the diagnostic sensitivity was 100%, 14:00 - 15:30 Room B Musculoskeletal SS 310 Arthritis Moderators: A. Chevrot; Paris/FR P. Peloschek; Vienna/AT B-141 14:00 Phase-contrast radiography in a clinical setting, using a high-resolution digital imaging system with a small-focus X-ray tube instead of synchrotron radiation: Quantitative analysis of bone mass processed by wavelet transformation for the earlier detection of rheumatoid arthritis J. Tanaka, H. Oda, T. Mimura, C. Honda, H. Oohara, Y. Wada, H. Kawasaki, A. Kondou, N. Funakoshi; Iruma-gun/JP ([email protected]) Purpose: To establish a method for the quantitative evaluation of osteoporosis in early-stage rheumatoid arthritis (RA) using phase-contrast radiographic (PCR) technology instead of synchrotron radiation. Methods and Materials: A new X-ray imaging system consisted of a tungstenanode X-ray tube with a 123-Вµm focal spot and a computed radiography (CR) system with a spatial resolution of 43.75 Вµm. The distances between the focal spot and object, and the object and CR plate were 0.65 and 0.49 meters, respectively. The distance from the object to the CR plate creates an edge-enhancement effect due to phase-shift of the X-ray after passing through the object, to give sharper X-ray images, i.e., PCR technology. PCR as well as conventional X-ray imaging were performed on the hands of 40 patients with stage 1 and 2 RA, and in 34 healthy volunteers. Raw image data of hands in a fixed area were processed by wavelet transformation. Pixels in images that exceeded a fixed threshold were counted as bone trabeculae, and the percentages of extracted pixels were considered area ratios (AR) to indicate bone mass. Results: Average AR values were 27.3% for patients and 33.0% for volunteers (p 0.05). The conventional X-ray system did not reveal this difference among the same subjects. Conclusion: A decrease in bone mass in patients with RA was detected quantitatively by PCR technology. This technique may be used for the early detection of RA due to its high image-sharpness. B-143 14:09 MRI assessment of hand involvement from the very early to established rheumatoid arthritis P.E. Kosta, P. Voulgari, A.G. Zikou, C. Tsampoulas, A. Drosos, M.I. Argyropoulou; Ioannina/GR ([email protected]) Purpose: To detect differences in MRI findings of hand involvement in patients with very early (disease duration 3 months), early ( 12 months) and established RA. Methods and Materials: Fifty-seven patients fulfilling the American College of Rheumatology (ACR) criteria for RA, 26 with very early (group 1), 18 with early (group 2) and 13 with established disease (group 3) were enrolled in the study. MRI using T1, fat-suppressed T2 and contrast-enhanced T1-weighted sequences were performed in the dominant hand. Assessment of bone marrow edema, synovitis and bone erosions was performed by volumetric analysis and by the Omeract RA scoring system. A B C D E F G H S171 Friday Purpose: To validate a triple-echo gradient-echo sequence for measuring the fat content of the liver, using 1H magnetic resonance spectroscopy (1H-MRS) as the reference standard. Methods and Materials: This prospective study was approved by the appropriate ethics committee, and written informed consent was obtained from all patients. In 107 patients with type 2 diabetes (46 men; 61 women; mean age, 59 years), 3.0-T single-voxel point-resolved 1H-MRS of the liver (segment VII) was performed to calculate the liver fat fraction from the water (4.3 ppm) and methylene (1.3 ppm) peaks, corrected for T1 and T2 decays. Liver fat fraction was also computed from triple-echo (consecutive in-phase, opposed-phase and in-phase echo times) breath-hold spoiled gradient-echo sequence (flip angle, 20В°), by estimating T2* and relative signal loss between in- and opposed-phase corrected for T2* decay. Pearson’s correlation coefficient, Bland-Altman’s 95% limit of agreement and Lin’s concordance coefficient were calculated. Results: Mean fat fractions calculated from the triple-echo sequence and 1H-MRS were 8.8% (range, 0.7-33.6) and 8.7% (range, 0.2-34.1), respectively. Mean T2* time was 14.7 msec (range, 4.4-25.4). Pearson’s correlation coefficient was 0.987 (P 0.0001) and Lin’s concordance coefficient was 0.986 (P 0.0001). Conclusion: A breath-hold triple-echo gradient-echo sequence with a low flip angle and corrections for T2* decay is accurate for quantifying fat in segment seven of the liver. Given its excellent correlation and concordance with 1H-MRS, this triple-echo sequence could replace 1H-MRS in longitudinal studies. specificity was 93.7%, the positive predictive value was 85.7%, and the negative predictive value was 100%. The mean value of PDE/B-ATP ratio was 5.06p0.62, and 95% CI was 4.75-5.37 in the rejection group vs. 3.21p0.49 and 3.07-3.35 in the normal liver transplantation group. Given the threshold 4.17, the diagnostic accuracy was 100%, specificity was 97.9%, the positive predictive value was 94.7%, and the negative predictive value was 100%. (b) The ratios of B-ATP/Pi decreased in biliary duct stricture group, while they increased in chronic rejection group. There were similar changes in the ratios of PME/Pi. (c) pH values increased in biliary duct stricture group and chronic rejection group. (d) Histological specimens showed focal loss of hepatocytes, degeneration, and hepatocytic atrophy. Conclusion: 31P-MRS imaging is valuable in detecting the metabolism of the liver after transplantation, and suggests that alterations in the phospholipid metabolism may be a useful future direction of research. Scientific Sessions Results: Analysis of variance (ANOVA) followed by the Least Significant Difference (LSD) test showed significant difference in edema and erosions between early and established RA, p 0.05. No significant difference was found in synovitis. Conclusion: Edema, erosions and synovitis are findings in very early RA. Significant worsening of edema and erosions takes place during the first year of disease. B-144 14:18 A simplified MRI score of one hand to monitor rheumatoid arthritis in daily practice C. Cyteval1, A. Miquel2, D. Hoa1, J.-P. Daures1, X. Mariette2, B. Combe1; 1 Montpellier/FR, 2Le Kremlin-BicГЄtre/FR ([email protected]) Purpose: To develop an easy, reproductive and workable method for hand MRI scoring of arthritis correlate with the referential OMERACT rheumatoid arthritis magnetic resonance imaging score (RAMRIS). Methods and Materials: Of the 813 patients from the ESPOIR cohort (a French multicentric cohort of adults with early arthritis), 43 underwent baseline MRI examinations. A simplified score was defined by statistically identifying the data of high influence in RAMRIS. Then its correlation with RAMRIS was test using the spearman method. Last, intra and inter-observer reproducibility of the 2 scores were calculated. Results: Only the right hand was analysed for the new score. Bone areas for the study of erosions and oedema were reduced from 23 to 9 corresponding to the most eroded bones found with RAMRIS. The scale for erosions was reduce to 5 grades, synovitis graded as absent, mild or important and oedema absent or present. The simplified score was highly correlated with RAMRIS (r=0.88, 0.88 and 0.90, respectively, for erosion, synovitis, and oedema). Intra-reader kappas were good to excellent for RAMRIS and the simplified score for erosion (K=0.67, 0.85) synovitis (K=0.81, 0.89) and oedema (K=0.94, 0.97). Inter-reader kappas were moderate to good for RAMRIS (K= 0.58 to 0.74), while kappas were good to excellent using the simplified score (K= 0.72 to 0.78) with high significant difference compared to RAMRIS for erosion and oedema. Conclusion: This reproductive simplified score could be helpful for the use of MRI in daily practice to monitor joint damage in rheumatoid arthritis. B-145 14:27 Only erosions - but not bone marrow edema or contrast-medium enhancement - are specific features in pre-diagnosis MRI of ankylosing spondylitis M.C. Wick1, R.J. Weiss2, W. Jaschke1, A. Klauser1; 1Innsbruck/AT, 2Stockholm/SE ([email protected]) Purpose: To determine the most relevant diagnostic radiological features in prediagnosis magnetic resonance imaging (MRI) of patients with ankylosing spondylitis (AS) compared to patients with sacroiliac involvement of other rheumatic diseases or unspecific degenerative cause. Methods and Materials: We prospectively collected and systematically analyzed laboratory values, clinical data and initial pre-diagnosis contrast-medium enhanced MRIs of 179 patients (46 male/133 female) admitted to the Radiology Department between 2003 and 2006 for evaluation of the cause of low back pain. Standardized pre-diagnosis MRI sequences were semi-quantitatively assessed for statistical comparisons. Results: Of all the 179 patients, 27 (15.1%) were diagnosed with AS at a mean (SD) of 21.6 (40.5) days after the initial pre-diagnosis MRI. The remainder had sacroiliac involvement of other rheumatic diseases or HLA-B27-negative unspecific spondylarthropathies. While joint space irregularities, bone marrow edema, cysts and contrast-medium enhancement could inconsistently be found in MRIs of all patients, only erosions were statistically significantly (P 0.01) associated with radiological findings in patients who were later diagnosed with AS. The presence and score of erosions statistically significantly (P 0.01) correlated with laboratory values of inflammation. Conclusion: Only erosions, but not bone marrow edema or contrast-medium enhancement, are specific measurable radiological findings in the pre-diagnosis MRI of patients with AS. S172 A B C D E F G F H B-146 14:36 Are flexion views by computed tomography useful to evaluate anterior atlantoaxial subluxation in rheumatoid arthritis? T. SГ¶derman, A. Sundin; Uppsala/SE ([email protected]) Purpose: This study compared computed radiography (CR) with computed tomography (CT) for evaluation of anterior atlantoaxial subluxation (AAS) in patients with rheumatoid arthritis (RA). Methods and Materials: A total of 23 RA patients visiting the outpatient clinic of orthopaedic surgery entered this prospective study. CT examination was performed with the patients supine, with the head and neck in the neutral and flexed positions. Two routine CR of the cervical spine were performed in the neutral and flexed positions. The amplitude of AAS was defined by measuring the distance between the posterior surface of the anterior arch of the atlas and the ventral surface of the dens. Unstable AAS was considered to be present when the difference between AAs in the flexed and neutral position was r2 mm. Results: Diagnostic CT images of the neck in neutral position and flexion were obtained in 23 patients. None reported major symptoms during imaging and none of the examinations was interrupted. Neutral and flexion CRs were obtained in 21 patients. In 12 cases, the magnitude of AAS in flexion was greater in radiography than in CT. In five patients, CT was not able to demonstrate unstable AAS detected by radiography. In two patients, radiography was not able to demonstrate unstable AAS detected by CT. Conclusion: The magnitude of AAS is often smaller when measured by functional CT than by functional radiography. Therefore, the result of functional CT alone is not reliable. Functional radiographs are needed to show the magnitude of the AAS instability. B-147 14:45 The validity of the New York radiological grading criteria in diagnosing sacroiliitis by CT M. Geijer, G. Gadeholt GГ¶thlin, J. GГ¶thlin; Gothenburg/SE ([email protected]) Purpose: To validate the New York criteria grading in CT of the sacroiliac joints. Methods and Materials: With the aid of the NY criteria, in 1,304 CT studies, perform an assessment of inflammatory and degenerative changes as well as of normal anatomic variants: joint space width and shape; erosions; distribution, type and width of sclerosis; involvement of the joints in sacroiliitis. Results: There was definite radiological sacroiliitis in 420 joints of 251 patients. Of these, more than 2/3 of the joint was involved in 71.0% of the joints. Sclerosis in the ilium was much more prevalent than sacral sclerosis. With increasing NY grade, iliac sclerosis width and extent increased, transition from sclerosis to normal bone was indistinct at a higher rate, and the structure of sclerosis was more inhomogeneous. Erosions in the joint surfaces were localized predominantly on the iliac side. Conclusion: Only multiple or large erosions seem to be a valid solitary diagnostic sign. Solitary erosions need supplemental evidence from other inflammatory signs. Inflammatory sclerosis may be distinguished from degenerative sclerosis and can sometimes support early diagnosis. Joint space width, joint shape, bone mineral content, or enthesopathy have no place in sacroiliitis diagnosis on CT. The NY criteria are not ideal for use with CT. A practical classification of sacroiliitis on CT is proposed with the grading: no disease, suspect disease, and definite disease. B-148 14:54 Initial experience of dual energy CT for the detection of UA deposition in patient with gout W. Liu, H.D. Xue, Z.Y. Jin, H. Sun, X. Wang; Beijing/CN ([email protected]) Purpose: To assess the potential of dual energy CT (DECT) for the detection of uric acid (UA) deposits in the feet of patients with gout. Methods and Materials: A total of 17 patients (male, mean age 50.9 years, range 29-85 years) with known gout and 10 healthy subjects (male, 28-82 years old, mean age 47.8 years) were scanned on a dual source CT scanner (Definition, Siemens Healthcare, Forchheim, Germany) from ankle to toe in dual energy (DECT) mode (tube voltage 80 and 140 kV). Calculation was done with a ratio value of 1.25. Color coding was used to display the localization of UA deposits in the patient cohort. Results: With DECT,17/17, 8/17, 8/17, 5/17, 2/17 and 4/17 of patients with gout were found to have UA deposits in the metatarsophalangeal joints, medial malleolus, lateral malleolus, tarsal bones, phalanges of the toes and around the calcaneus, respectively. In gouty patients, 44.1% (75 of 170) of metatarsophalangeal joints were affected, though with no palpable tophus in most cases.UA deposits in the first metatarsophalangeal joints were found in all gouty patients. No UA deposit was found in healthy subjects. Scientific Sessions Conclusion: With DECT techniques, localization of UA deposits can be demonstrated in gouty patients. Further investigations need to be done for accuracy evaluation. 15:03 Dual energy computed tomography: A promising new technique for assessment of gout S. Nicolaou, J. Grebenyuk, A. Eftekhari, S. Galea-Soler, C. Yong-Hing, W. Wan, T. Orton, P. Munk; Vancouver, BC/CA Purpose: The dual energy CT (DECT) application has been proven to accurately confirm uric acid deposition within kidneys. The authors of this pilot study worked to expand this application to allow visualization of monosodium urate (MSU) crystal deposition in gout arthropathy. It is vital for clinicians to differentiate gout from other inflammatory arthropathies such that specific and timely treatment can be provided. Methods and Materials: This study was approved by the institutional review board. Retrospective analysis of 13 patients with aspiration-proven gout (11 males, 2 females; mean age 61.2 years) and 10 control subjects with no history of gout who underwent DECT evaluation of hands/wrists, elbows, knees and feet/ankles was performed. Images were reviewed independently by two DECT-trained radiologists. A rheumatologic assessment of subjects with aspiration-proven gout and a complete chart review of all study participants were performed. Results: DECT was more accurate in identifying the degree of disease burden in gout. The number of MSU crystal deposition sites found in patients was four times higher in DECT (200) than by clinical assessment (53) (P = 0.002). DECT was significantly better at identifying disease in the hand/wrist, knees and feet/ankles (P 0.015). Subclinical sites, such as deep ligaments and tendons not previously described in literature, were also appreciated on DECT. Conclusion: Our study suggests that DECT is highly accurate in diagnosing gout and delineating the extent of subclinical disease. DECT has further potential to be used as a tool to monitor the response to urate-lowering therapy in tophaceous gout. B-150 15:12 Vertebral fractures in patients with ankylosing spondylitis: A retrospective analysis of 66 patients S. Sterl, J. Altenbernd, S.P. Lemburg, S.A. Peters, V. Nicolas, C.M. Heyer; Bochum/DE ([email protected]) Purpose: Retrospective analysis of vertebral fractures in patients with ankylosing spondylitis (AS) for evaluation of associations with mortality, concurrent neurological deficits, and other complications. Methods and Materials: Image analysis (conventional radiographs, CT, MRI) was applied to all patients with AS admitted between 1997 and 2007 due to vertebral fractures pertaining to fracture localisation and classification. Patient characteristics, trauma mechanism, neurological symptoms, and other complications were documented. Results: 66 patients (58% male, age 64p11 years) were enrolled in the study. 74% of patients suffered from minor trauma. 51 and 56% had cervicothoracic and thoracolumbar fractures, respectively, while 8% had multi-level fractures. 63% of patients suffered combined vertebrodiscal fractures. 70% revealed neurological symptoms, significantly correlating with spinal stenosis (p=.024; Odds Ratio 4.265) and hyperlordosis (p=.014; OR 4.806). 68% developed complications with noncombined fractures (p=.042; OR 4.954) and paravertebral hematomas (p=.009; OR 16.969) representing independent risk factors. Female gender (p=.005; OR 15.617) and conservative therapy (p=.040; OR.094) exerted significant influence on the mortality rate. Conclusion: Vertebral fractures frequently occur in patients with AS after minor trauma and often lead to neurological symptoms, which in turn are associated with spinal stenosis and hyperlordosis. Paravertebral hematomas and non-combined fractures are accompanied by higher incidences of other complications. Female gender entails higher mortality. Room C GI Tract SS 301b Friday B-149 14:00 - 15:30 CT colonography Moderators: S. Agostini; Marseille/FR T. Mang; Vienna/AT B-151 14:00 Full-laxative versus minimum-laxative CT colonography: Prospective comparison of diagnostic performance K. Nagata1, T. Oikawa2, S. Kudo3, H. Yoshida1; 1Boston, MA/US, 2Tokyo/JP, 3 Yokohama/JP ([email protected]) Purpose: To prospectively compare the full-laxative fecal-tagging virtual colonoscopy (VC) with minimum-laxative fecal-tagging VC in the detection of polyps with 64-detector computed tomography (CT). Methods and Materials: One-hundred and one patients with high risk for developing colorectal cancer were alternately allocated to either a full-laxative fecal-tagging group (n = 51) or a minimum-laxative fecal-tagging group (n = 50) before undergoing VC. The full-laxative regimen consisted of the administration of 2 L of polyethylene glycol solution with 20 mL of Gastrografin for fecal tagging. The minimum-laxative regimen consisted of the ingestion of 45 mL Gastrografin over 3 days and 10 mL of sodium picosulfate solution the night before the CT scanning. We assessed the accuracy of polyp detection in each preparation group using optical colonoscopy as the reference standard. Results: In the full-laxative fecal-tagging group, per-patient sensitivity, specificity, and positive and negative predictive values for polyps r6 mm were 97, 92, 88, and 98%, respectively, while those of the minimum-laxative fecal-tagging group were 88, 68, 56, and 92%, respectively. There was no statistically significant difference in the sensitivities (p 0.05), whereas the specificities were statistically significantly different (p 0.05). For polyps r10 mm, sensitivity was 100% in both the full-laxative fecal-tagging (15/15 polyps) and minimum-laxative fecal-tagging (9/9 polyps) groups. Conclusion: Full-laxative and minimum-laxative fecal-tagging VC yielded an equally high sensitivity in the detection of polyps r6 mm; thus, both can be options for all patients who undergo colorectal cancer screening. B-152 14:09 Virtual tagging for better laxative-free CT colonography J. NГ¤ppi1, H. Yoshida1, M.E. Zalis1, S. Gryspeerdt2, P. Lefere2; 1Boston, MA/US, 2 Roeselare/BE ([email protected]) Purpose: To assess the potential of virtual tagging (VTG) in improving the detection accuracy of laxative-free CT colonography (CTC). Methods and Materials: Forty-six patients were prepared for 1-2 days prior to CTC in two institutions by dietary tagging with barium (from 12.5 mL with 40% to 250 mL with 2.1% w/v concentrations) or non-ionic iodine (10 mL diluted in 150 mL of beverages). No bowel cleansing or laxatives were used. The CTC was performed in supine and prone positions by 3 CT scanners with 1.0-2.5 mm collimations, 0.7-2.5 mm reconstruction intervals, 28-110 mA currents, and 120-140 kVp voltages. The findings of post-CTC colonoscopy were correlated with the CTC data. A fully automated VTG method was used to highlight poorly tagged materials and partial-volume artifacts. A previously validated fully automated scheme was used to detect polyps without and with the VTG. The detection accuracy was evaluated by use of the jack-knife free-response receiver operating characteristic test. The sources of false positives (FPs) were identified. Results: All cases were tested regardless of diagnostic quality. There were 10 adenomas: 6 were 6-9 mm and 4 were 10 mm. The accuracy of automated detection with (without) VTG was 90% at 2.7 FPs (70% at 2.4 FPs) per scan for adenomas 6 mm. The improvement by VTG was statistically significant (p 0.05). With VTG, the leading sources of FPs were completely untagged feces (55%) and thickened folds (10%). Conclusion: The application of VTG can yield significant improvement in the accuracy of polyp detection in laxative-free CTC. A B C D E F G H S173 Scientific Sessions B-153 14:18 Electronic cleansing for CT colonography: Does it help the performance of computer-aided detection software in a high-risk population for colorectal cancer? J. Wi, S. Kim, J. Lee, J. Lee, J. Han, B. Choi, S. Kim; Seoul/KR ([email protected]) Purpose: To compare the performance of computer-aided detection (CAD) software for CT colonography (CTC) with and without the use of electronic cleansing (EC) in a high-risk population for colorectal cancer tagged with robust fecal tagging (FT) protocol. Methods and Materials: A total of 32 patients suspected of having colonic polyps underwent CTC followed by a same-day optical colonoscopy (OC). All patients underwent a dry preparation using magnesium citrate and FT with 24-28 g barium and 50 ml of gastrografin. Each CTC data set was processed with colon CAD (Philips) with and without the use of EC. Per-polyp sensitivity was calculated using colonoscopy as a reference standard. The average number and cause of false positives (FPs) were also analyzed. Results: A total of 86 polyps (54 polyps, 6 mm; 16, 6-9 mm; 16, r10 mm) were detected in 29 of 32 patients by OC. Per-polyp sensitivities of the data sets with and without EC were 93.8 and 84.4% for polyps r6 mm and 100 and 87.5% for polyps r10 mm, respectively. Per-polyp sensitivities were not significantly different between the two data sets. The average number of FPs with EC was 6.3, which was significantly larger than that (3.1) without EC (P 0.0001). The most common cause of FPs was ileocecal valve in both data sets (29.7% with EC, 32.1% without EC). However, untagged feces was a significantly less common cause of FPs (5.9% with EC, 11.6% without EC) with EC, EC-related artifacts being more common (28.7% with EC, 0% without EC; P 0.05). Conclusion: Comparable per-polyp sensitivity can be achieved when CTC CAD is used with EC as compared to without EC. However, the significantly larger number of FPs with EC remains to be improved. B-154 14:27 CT colonography: Computer-assisted detection (CAD) of colorectal cancer in 132 patients C. Robinson1, G. Iinuma2, W. Topping1, S. Punwani1, S.A. Taylor1, L. Honeyfield1, S. Halligan1; 1London/UK, 2Tokyo/JP ([email protected]) Purpose:CT colonography (CTC) is well established for polyp detection in colorectal cancer screening. Detection of polyps has recently been enhanced by the introduction of computer-assisted detection (CAD). However, the potential for CAD detection of established cancer in symptomatic patients has attracted less attention. Large case series are especially needed in this context, especially since most CAD algorithms have not been developed with cancer in mind. Methods and Materials: A total of 132 symptomatic patients with proven colorectal cancer were recruited from 6 centres. Multi-detector CTC colonography had been performed in each using a standard technique, but with variable bowel preparation. DICOM data was uploaded to a PC workstation and a proprietary CAD algorithm (Medicsight ColonCAD 3.1) applied to all data sets. A single observer interrogated each CTC, classifying individual CAD prompts as either true-positive if related to a cancer or false-positive if elsewhere (including those on polyps). Colonoscopic data were used to aid matching. Results: Of the 132 cancers, 119 (90.2%), 117 (88.6%), 115 (87.1%) and 98 (74.2%) were detected at filter settings of 0, 50, 75 and 100, respectively. Of those cancers detected, 42.9, 41.9, 47.8 and 54.1% were only prompted by CAD on either the prone or supine acquisition at filter settings of 0, 50, 75 and 100, respectively. False-positive prompts decreased with increasing filter value (median 65, 57, 45 and 24 per patient at values of 0, 50, 75 and 100, respectively), but many data sets were poorly prepped. Conclusion:CAD is sensitive for the detection of symptomatic colorectal cancer, but must be applied to both prone and supine data sets. B-155 14:36 Influence of a CAR software on different experienced readers: Primary 3D fly-through approach versus 3D + CAR approach M. Rengo, R. Ferrari, F. Vecchietti, D. Bellini, D. Caruso, P. Paolantonio, A. Laghi; Latina/IT ([email protected]) Purpose: To compare the performances of different experienced readers using a primary 3D fly-through approach with and without the use of a CAR analysis. Methods and Materials: Three readers evaluated 50 patients with 100 endoscopically proven polyps (ranging from 3 to 40 mm) and different colonic preparations (18 fluid tagging, 32 full cathartic preparation). Data set analysis was performed on a VIATRONIX workstation equipped with V3D colon (version 1.3) software and with Medicsight Colon CAR 1.3 software. Per-polyp sensitivity, inter-reader agreement, S174 A B C D E F G F H mean reporting time and false positive were evaluated for each approach. Results: Less experienced readers had increased per-polyp sensitivity respectively from 75 and 61% for 3D analysis to 86 and 74% for primary 3D + CAR analysis with a significant difference (P = 0.001 and P = 0.01), while no significant differences were found for the expert ones (P = 0.06). Less experienced readers were faster when assisted by CAR, but no significant differences were found in the mean reading time of all readers (P = 0.5/0.07/0.1). Mean false-positive findings for CAR analysis were 12 (SD 13). There was a decrease in the false positive for all readers when assisted by CAR, especially for the less experienced ones. Interreader agreement was higher among all readers when assisted by CAR (0.33 to 0.63/0.39 to 0.62/0.58 to 0.65) Conclusion: Our study demonstrated that less experienced readers, if assisted by CAR, can significantly increase their sensitivity. They have other not significant advantages like the reduction in the false-positive rate and mean reporting time. B-156 14:45 CT colonography polyp matching: Differences between experienced readers M.H. Liedenbaum, A.H. de Vries, P.M.M. Bossuyt, E. Dekker, J. Stoker; Amsterdam/NL ([email protected]) Purpose: To investigate if experienced readers differ in the matching of CT colonography (CTC) and optical colonoscopy (OC) polyp cases and to explore the reasons for these differences. Methods and Materials: A total of 28 pre-selected CTC-OC matching cases were presented to eight experienced CTC readers. The cases represented a broad spectrum of findings, not completely fulfilling the often-used matching criteria: CTC and OC polyp within 50% size range, similar morphology, location in the same or adjacent colonic segment. Matching was performed using CTC examinations, videotaped OCs and OC reports. In 21 cases, one OC and CTC polyp were shown (single polyp cases). In seven cases, multiple polyps per case had to be matched (38 CTC polyps and 44 OC polyps). Results: The number of matches per reader varied from 13 to 19 in single polyp cases. Almost complete matching agreement was observed in 15 cases: seven or eight readers indicated a match. Low agreement was found in the remaining six cases: only four or five readers indicated a match. In five of these six cases, a large size difference ( 50%) existed between the CTC and OC polyp. In the multiple polyp cases, matching varied from 27 to 35 CTC polyps; 9-11 matches for polyps r10 mm, 8-11 for polyps 6-9 mm and 7-14 for polyps 6 mm. Conclusion: Experienced CTC readers agree to a considerable extent in the matching of selected cases, but non-negligible differences in matching exist. Our proposal is to consider consensus matching for difficult cases. This study was performed in collaboration with the International CTC Matching Group. B-157 14:54 Defining the optimal operating point for colon computer-aided detection in clinical practice: Influence of CAD-generated false positives on reader performance and diagnostic confidence for CT colonography S.A. Taylor1, J. Brittenden2, J. Lenton3, H. Lambie3, A. Goldstone3, P. Wylie4, D. Tolan3, D. Burling4, S. Halligan1; 1London/UK, 2Wakefield/UK, 3Leeds/UK, 4 Harrow/UK ([email protected]) Purpose: The optimum operating point for computer-aided-detection (CAD) software in CT colonongraphy (CTC) is poorly defined. The purpose was to investigate whether increasing numbers of false positive (FP) CAD prompts are detrimental to reader sensitivity and diagnostic confidence for non-expert readers. Methods and Materials: A total of 50 CTC data sets (male 29, mean age 65 years; 25 containing 35 polyps r 5 mm) were selected where CAD had 100% polyp sensitivity at each of the two sphericity settings (0 and 75), but differed greatly in FP number. Data sets were read by five trained readers twice, once at each sphericity, at an interval of 6 weeks. Findings, report time and confidence pre and post secondread CAD were noted. Sensitivity, specificity, reading times and confidence were compared using the paired exact test and t test, respectively. Receivers operating characteristic curves were generated based on case classification. Results: CAD generated a mean 15 and 42 FP at sphericity 75 and 0, respectively. CAD at both settings increased per patient sensitivity (from 82 to 87%, P = 0.03), and per polyp sensitivity (by 8 and 10% for sphericity 0 and 75, respectively, P 0.001), although specificity decreased (84-79%). There was no difference in reader sensitivity, specificity or confidence between CAD sphericity settings (P = 1.0, 1.0, 0.11, respectively). AUC was 0.78 [95% CI 0.70-0.86] and 0.77 [95% CI 0.68-0.85] for sphericity 0 and 75, respectively. CAD added median 4.4 (IQR 2.7-6.5) and 2.2 minutes (IQR 1.2-4.0) for sphericity 0 and 75, respectively (P 0.001). Conclusion: Larger numbers of false positives do not negate the beneficial effect of CAD on reader sensitivity or confidence, but reduce efficiency. Scientific Sessions B-158 15:03 Colonic flat lesions detection using 64-MDCT colonography and a CAD system: Preliminary results F. Iafrate, A. Stagnitti, A. Pichi, R. Ferrari, D. Caruso, F. Vecchietti, A. Laghi; Rome/IT ([email protected]) B-159 15:12 Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening M.H. Liedenbaum1, A.F. van Rijn1, A.H. de Vries1, H.M. Dekker2, M. Thomeer3, P. Fockens1, P.M.M. Bossuyt1, E. Dekker1, J. Stoker1; 1Amsterdam/NL, 2 Nijmegen/NL, 3Rotterdam/NL ([email protected]) Purpose: To determine whether CT colonography (CTC) is an effective triage technique in faecal occult blood test (FOBT) positives. Methods and Materials: Consecutive guiac (G-FOBT) and immunochemical (IFOBT) FOBT positive screening participants scheduled for colonoscopy underwent CTC with iodine tagging bowel preparation in three different institutions. Each CTC was read by two independent, experienced observers. Per-patient positive and negative predictive values (PPV and NPV) were calculated based on double reading with a 10 mm CTC cut-off lesion size (polyp or carcinoma) and comparison with segmental unblinded colonoscopy. Patient acceptance was evaluated with questionnaires. The costs of initial clinical management were calculated for a strategy with CTC triage and a strategy without triage before colonoscopy. Results: A total of 302 FOBT positives were included (54 g-FOBT and 248 I-FOBT). Of all, 22 FOBT positives (7%) had a colorectal carcinoma, 142 (47%) had a lesion r10 mm and 210 (70%) had a lesion r6 mm. The participants considered colonoscopy to be significantly more burdensome than CTC. The per patient PPV of CTC for the detection of colonoscopy lesions r10 mm was 84% (95% CI: 77-91%; 90% for g-FOBT positives and 82% for I-FOBT positives); the NPV was 84% (95% CI: 77-91%; 83 and 84%, respectively). Costs with CTC as triage technique were 17% higher compared to performing direct colonoscopy in all FOBT positives. Conclusion: CTC with limited bowel preparation has reasonable predictive values in an FOBT-positive population, but due to the high prevalence of clinically relevant polyps in FOBT positives, the total costs will increase if CTC is used as a triage technique. B-160 15:21 CT colonography: C-RADS 2 - which is the patient’s preferred follow-up colon test and interval? F. Turini, E. Neri, F. Cerri, P. Vagli, M. Barattini, C. Bartolozzi; Pisa/IT ([email protected]) Purpose: According to the CT Colonography (CTC) Reporting and Data System (CRADS), the category 2 is the presence of 3 medium sized polyps. In these patients a follow-up at 3 years, is reasonable, taking into account age, sex, comorbidities, patient's preference. The aim of this study was to evaluate the patient's preferred follow-up colon test and the time interval in case of C-RADS 2. Methods and Materials: We retrospectively reviewed the data of 673 patients who underwent CTC between 2005 and 2008. A total of 445 patients were negative at CTC (C-RADS 1; 66%), 133 were found to have 3 medium size polyps 14:00 - 15:30 Room F1 Genitourinary SS 307 Kidney: Morphological and functional studies Moderators: G. Manenti; Rome/IT C. Roy; Strasbourg/FR B-161 14:00 The extrinsic ureteropelvic junction obstruction caused by “anomalous” crossing vessels: Does it exist? J. Petersen, P. Rehder, K. Rapf, B. Glodny; Innsbruck/AT ([email protected]) Purpose: To investigate whether or not “anomalous” crossing vessels (CVs) may have an influence on the drainage and width of the renal pelvis and ureters. Methods and Materials: 1043 subsequent patients were enrolled into the study. 0.625 mm collimated 64-slice-MDCTs with different phases, including an arterial phase, have been assessed by two observers in consensus. Results: 2077 kidneys were supplied by 2656 arteries and 2411 veins. The width of the kidney pelvis was 8.8p4.4 mm on the right, and 8.6p6 mm on the left side. On the right side, in 12% of the patients at least one "additional" artery was crossing the renal pelvis or ureters anteriorly, posteriorly (5.7%), anteriorly and posteriorly (1.1%); in 8.6% at least 1 vein was crossing anteriorly, posteriorly (11.1%), anteriorly and posteriorly (2.3%). On the left side, in 11.8%, an artery was crossing anteriorly, posteriorly (6.1%), and anteriorly and posteriorly (1.5%); in 1.5%, a vein was crossing posteriorly, and in 0.2% anteriorly. Variance analyses did not reveal any relations between CVs and the width of the renal pelvis or ureter. CVs did not have any effects with respect to hydronephrosis either, as shown by multiple regression analysis models. Gender, position and size of the kidneys show moderate positive correlation with the width of the urinary tract (p 0.0001). Conclusion: In this large cohort of unselected patients, “anomalous” crossing vessels did not reveal any verifiable effects on the upper urinary tract. Therefore, we disbelieve the existence of the so called “extrinsic urteropelvic junction obstruction” caused by CVs. B-162 14:09 Feasibility study of blood oxygenation level-dependent MRI in chronic kidney disease X. Xu, H. Ling, W. Chai, K. Chen, W. Fang; Shanghai/CN ([email protected]) Purpose: To evaluate feasibility of blood oxygenation level-dependent (BOLD) MR imaging in assessment of renal functions in patients with chronic kidney disease (CKD). Methods and Materials: 57 patients with CKD and 70 healthy volunteers underwent BOLD MR imaging of the kidneys. The patients were classified into 5 stages according to the K/DOQI CKD (kidney disease outcome quality initiative). R2* of the cortical and medullar of the kidneys were calculated and compared. Reproducibility was assessed by repeating the same protocol in 10 randomly selected volunteers after 1-6 months. The R2* were compared between patients and volunteers ageand sex-matched. The R2*of patients were compared among different stages. For statistical analysis, Student t tests, ANOVA, Pearson’s correlation tests and Spearman’s correlation tests were used. Results: In all volunteers, medullary R2* were higher than cortical R2* (18.14/ secp2.51, 12.63/secp1.40). No statistically significant difference was found in the A B C D E F G H S175 Friday Purpose: To evaluate the ability of CAD software to detect morphologically flat lesions at CT colonography. Methods and Materials: The CTC datasets of 31 patients with 34 endoscopically proven flat lesions were loaded onto a workstation equipped with CTC viewing software and reviewed with and without CAD by two radiologists experienced in CTC interpretation fully aware of the colonoscopic report. A total of 28 patients underwent fecal tagging preparation before CTC and remaining 3 patients underwent full cathartic prep. Results: Eight of 34 lesions were missed by reading CTC examination using 2D as primary approach and 3D as problem solving without CAD. CAD detected 32 of 34 flat lesions. Two radiologist in consensus using CAD software detected 30 of 34 lesions and two lesions detected by CAD was not reported as flat lesions due to low conspicuity. Nineteen lesions were of 3 mm in height, and 11 ranging in height between 1 and 2 mm. Two lesions with the height of 1 mm or less were not seen on CT Colonography. Six lesions located on the haustral fold showed higher conspicuity on the 3D endoluminal view than on the colon window setting 2D view. Conclusion: In conclusion, 25% of flat lesion in our population was missed by radiologists without CAD that improved flat lesion detection from 75 to 90% of proven lesions. Visualized flat lesions were 3 mm or lower in height and 6 mm or greater in diameter. Lesions with a height of 1 mm or less were not seen on CT colonography. (C-RADS 2; 20%) and 95 had r3 medium size polyp or larger lesions (C-RADS 3 and 4; 14%). In all C1 cases a 5-year follow-up was suggested; in C2 a 1-3 years follow-up by means of CTC or colonoscopy. C3 and C4 were immediately referred to colonscopy. We estimated the number of C-RADS 2 patients followed-up with CTC or colonoscopy and the patient's preferred follow-up time interval. Results: Data collected in a 3-year follow-up showed 64/133 (48%) patients who accepted a follow-up and choosen CTC to repeat the colon test, with a maximum of 18 months follow-up. Sixty-nine out of 133 (52%) underwent colonoscopy. Among these 18 (13%) preferred to undergo immediate colonoscopy and 51 (38%) accepted a maximum of 18 months follow-up. Conclusion: The majority of patients classified as C-RADS 2 prefer to repeat the colon test by means of CTC, but all patients accept a maximum of 18 months follow-up, even when 3 years are proposed. Scientific Sessions repeat study of the volunteers (P 0.05). Patients with CKD had significantly lower renal medullary R2* (t=-4.383, P =0.000) than did volunteers (16.35/secp2.72 vs. 18.14/secp2.67). The medullary R2* were lower in CKD1, CKD4 and CKD5 patients than volunteers (P 0.05). There was an appositive correlation between the medullary R2* and sCr level (r=-0.250, P=0.011) in the patients. Conclusion: BOLD MR imaging is feasible and reproducible in the assessment of renal function, especially in the detection of early stage renal failure of CKD. B-163 14:18 Diffusion-weighted MR imaging of kidneys in healthy volunteers and patients with chronic kidney disease: Initial study X. Xu, W. Fang, K. Chen, H. Ling, W. Chai; Shanghai/CN ([email protected]) Purpose: To prospectively evaluate reproducibility of diffusion-weighted MR imaging in assessment of renal functions in healthy volunteers and feasibility to differentiate the renal functions of patients with chronic kidney disease (CKD). Methods and Materials: Seventy-two healthy volunteers and 43 patients underwent DW MR imaging of the kidneys with a single breath-hold. The patients were classified into 5 stages according to the K/DOQI CKD. Apparent diffusion coefficients (ADC) value of the kidneys was calculated with b 500 sec/mm2. Reproducibility was assessed by repeating the same protocol in 10 randomly selected volunteers after 1-6 months. The ADC values were compared between patients and healthy volunteers age- and sex-matched. The ADCs of patients were compared among different stages. For statistical analysis, Student t tests, ANOVA, Pearson’s correlation tests and Spearman’s correlation tests were used. Results: In all volunteers, difference between the cortex and medulla could not be observed in DW images. No statistically significant difference was found in the repeat study of the volunteers (P 0.05). Patients with CKD had significantly lower renal ADC (t=-4.383, P =0.000) than did volunteers. A liner correlation was found between the renal ADCs and stages of CKD (r=-0.492, P=0.000). There was an appositive correlation between the ADCs and sCr level (r=-0.374, P=0.000) in the patients. Compared with the volunteers, the lower ADCs was only found in the patients with sCr level higher (P 0.05). Conclusion: DW MR imaging is feasible and reproducible in the assessment of renal function, especially in the detection of early stage renal failure of CKD. B-164 14:27 MR diffusion-weighted imaging with apparent diffusion coefficient value in renal insufficiency at 3 T C. Roy, G. Bierry, A. Matau, M. Jeung, H. Lang; Strasbourg/FR ([email protected]) Purpose: To investigate the relationship between apparent diffusion coefficient (ADC) values measured by MR diffusion-weighted imaging (DW-MRI) in cases of renal insufficiency (RI). Methods and Materials: A total of 200 patients with various pathologies including 120 patients with moderate (GFR 40 mLВ· min) or severe (GFR 40 mLВ· min) RI were explored at 3 T (Achieva, Philips) with axial DWI SE-EPI (TR/TE : 5,546/53 ms, 5 mm, b value 0 and 1,000 s/mm2). They were divided into “control 50 pts”, “normal unique kidney 30 pts” and four groups of 30 pts: “moderate RI unique kidney”, “severe RI unique kidney“, “moderate RI both kidney “, “ severe RI both kidney “. ADC was measured at 150 mm2 ROI by two experienced radiologists, as well as images analysis performed. Statistical analysis was performed using SPSS software. ADC mean values and standard deviation of each group were calculated and compared using Student’s t-test. Results: Mean ADCs in control and normal unique kidney groups were both 1.9 x 10-3 mm2/ s. Mean ADCs of the four groups were as follows: 1.87 p 0.11, 1.82 p 0.17, 1.91 p 0.11 and 1.86 p 0.11 x 10-3 mm2/s, respectively. There was no statistically significant difference in renal ADCs among the four groups of RI and control group. On DWImages signal intensity was homogeneous for all types. Conclusion: The ADCs were no significantly different in impaired kidneys and normal functional kidneys. There was no correlation between the ADCs and GFR. DW-MRI of the kidney does not seem to be a reliable method to differentiate normal renal parenchyma and different renal diseases. B-165 14:36 MRI-based functional evaluation of the kidneys in patients with renal artery stenosis: Renal perfusion and blood flow analysis and their correlation with biochemical markers V. Zampa, S. Ortori, L. Faggioni, E. Guidi, V. Positano, S. Pinto, C. Bartolozzi; Pisa/IT ([email protected]) Purpose: To evaluate the usefulness of MRI-based perfusion and renal blood flow (RBF) analysis for renal function assessment in patients with suspected renovascular hypertension. Methods and Materials: Thirty-four patients (M:F=14:20, age 17-80 years, mean 58 years) with arterial hypertension underwent MRI of the upper abdomen on a GE Signa Excite HDx 1.5 T scanner. Perfusion-weighted imaging was performed running a free-breath multiphase T1-weighted fast-spoiled gradient-echo LAVA sequence starting after intravenous administration of a 3-ml bolus of Gd-BOPTA injected at 3 ml/s. Flow data were acquired through a 2D ECG-gated phase-contrast sequence centered perpendicularly to the course of each renal artery, eventually distal to stenosis site. Perfusion and flow analysis were carried out using homemade software (HippoKidney vers. 1.0, IFC-CNR, Pisa) and a dedicated plug-in (CV Flow 4, GE Medical Systems), respectively. Results: In kidneys with renal artery stenosis (RAS) compared with non-stenotic ones, RBF was significantly decreased (p=0.0104, Mann-Whitney test), timeto-peak (TTP) and mean transit time (MTT) were longer (p=0.0094, p=0.0009), while maximum upslope (MUS) and maximum signal intensity (MSI) were reduced (p=0.0281, p=0.04). In kidneys with RAS, both glomerular filtration rate (GFR) and serum creatinine levels correlated significantly with MTT, MUS, and MSI (rs=-0.4284/ p=0.04 and rs=0.5896/p=0.0039; rs=0.4838/p=0.0226 and rs=-0.6857/p=0.0004; rs=0.5001/p=0.0179 and rs=-0.6897/p=0.004, Spearman rank test), and a significant correlation was also detected between GFR and RBF (rs=0.4457/p=0.0429). Conclusion: Perfusion and blood flow analysis of the kidneys can provide information about renal function and could be incorporated in a routine MRI protocol for the assessment of patients with suspected renovascular hypertension. B-166 14:45 Drug-induced MR-pyelography in the evaluation of non-excreting kidneys M. Di Girolamo, G. Scavone, G. Argentieri, V. Vitale, L. Greco, V. David; Rome/IT ([email protected]) Purpose: To evaluate the accuracy of this technique in the visualization of nonexcreting-kidneys. Methods and Materials: 25 patients with non-excreting kidneys underwent druginduced MR-pyelography. 23 patients had undergone intravenous urography in the 10 days preceding MRI while 2 patients had undergone contrast-enhanced excretory MR-urography the day before. The examination was performed with a 3-D non-breath holding fat-suppressed Turbo SE sequence on coronal planes. To obtain maximum filling of both the collecting system, the diuresis was pharmacologically induced by administering saline solution together with furosemide. Two MR acquisitions were performed 5 and 10 minutes after diuresis induction. All the patients underwent abdominal plain radiograph and urinary cytology. Retrograde pyelography was performed twice at the beginning of the experience. Results: In 24 patients, non-excreting kidney was related to obstructive uropathy and in these cases drug-induced MR-pyelography allowed to detect the site of obstruction. Using conventional MR images, abdominal plain radiograph and urinary citology, the cause of the obstruction was always determined (8 renal collecting system tumors, 5 ureteral calculi, 3 retroperitoneal fibrosis, 1 ureteral obstruction due to lumbar lymphadenopathy and 7 uretero-pelvic junction syndromes). In one case, non-functioning kidney was due to renal tuberculosis. Conclusion: Drug-induced MR-pyelography allowed a morphological study of renal collecting system in patients with of non-excreting kidneys, avoiding the need to perform invasive retrograde pyelography, and could be considered the best diagnostic imaging modality to perform after US, especially in case of ureteral obstruction. B-167 14:54 Calculation of renal function by dynamic volume CT: Comparison with scintigraphy in renal donors C. Kloeters, S. Kandel, H. Meyer, L. Liefeldt, M. Johannsen, P. Rogalla; Berlin/DE ([email protected]) Purpose: To evaluate the feasibility of renal function calculation based on perfusion imaging of the kidneys and to compare the results with scintigraphy in renal donors. Methods and Materials: 10 patients underwent a dynamic volume CT (320-slice CT, Toshiba) of the kidneys. The imaging protocol consisted of 18 low-dose scans covering both kidneys following intravenous injection of 60 ml of contrast material S176 A B C D E F G F H Scientific Sessions B-168 15:03 Comprehensive assessment of renal function and vessel morphology in potential donors for kidney transplantation: An MRI-based approach C. Rossi, A. Boss, F. Artunc, S. Yildiz, P. Martirosian, C.D. Claussen, H. Dittmann, F. Schick, H.-P. Schlemmer; Tuebingen/DE ([email protected]) Purpose: Evaluation of potential living kidney donors is an expensive and timeconsuming procedure. In this study, an MR-based protocol for comprehensive assessment of renal function and kidney vessel morphology in potential kidney donors is presented. Methods and Materials: Eleven healthy candidates for kidney transplantation (mean age 46p14) participated in the study. Dynamic MR-nephrography was performed using a navigator-gated T1-weighted saturation-recovery MR sequence (trueFISP or turboFLASH). Images were acquired up to 60 minutes after a bolus injection of 4 ml of gadobutrol. The glomerular filtration rate (GFR) was evaluated from the renal clearance of gadobutrol within the extra-cellular fluid volume by exponential fitting of time-signal curves measured over the liver. MR-angiography (MRA) was performed using a T1-weighted 3D-Flash sequence. The overall measuring time resulted in approx. 80 minutes. For each subject, GFR data were compared to the results of radionuclide scintigraphy with Technetium-labeled DTPA from the same day. Results: Renal anatomy and vascular status could be successfully obtained in all subjects. GFR values estimated by MR-nephrography showed a good agreement to the scintigraphy data (mean GFR from MR-nephrography, 115p24 ml/min per 1.73 m2; mean GFR from scintigraphy, 112p24 ml/min per 1.73 m2). The BlandAltman plot showed a mean difference in measurements pairs of -2p12 ml/min per 1.73 m2. All measurement points were comprised within p2 standard deviations from the mean value. Conclusion: Comprehensive assessment of renal anatomy, function, and vessel morphology is feasible within one single MR examination. The proposed protocol may find immediate clinical application in the preoperative assessment of potential kidney donors. B-169 15:12 Early stage of renal dysfunction: Quantitative diagnosis with contrastenhanced ultrasonography, an initial experience W. Wang, Y. Dong, H. Ding, C. Li; Shanghai/CN ([email protected]) Purpose: To prospectively estimate the value of contrast-enhanced ultrasonography (CEUS) in the quantitative evaluation of renal cortex perfusion in patients suspected with early stage of renal dysfunction, with renal scintigraphy as the golden standard. Methods and Materials: The study protocol was approved by the hospital review board and each patient gave written informed consent. A total of 41 right kidneys in 41 consecutive patients (26 men, 15 women; mean age, 35 p 2 years) suspected of early renal dysfunction were examined with conventional Doppler ultrasonography (US) and CEUS. By an intravenous bolus injection of 1 ml SonoVue, a time-intensity curve (TIC) was created with QLAB software (PHILIPS iU22 system). The slope rate of elevation curve (A), descending curve (A), area under curve (AUC), derived peak intensity (DPI) and time to peak (TTP) were measured in the renal cortex with 5Г—5 mm ROI. Receiver operating characteristic (ROC) curves were used to predict the dignositc criteria of CEUS quantitative indexes. Results: DPI less than 12, A greater than 2 and AUC greater than 1,300 had high utility in the early stage of renal dysfunction, with 81, 73 and 78% specificity, 76, 73 and 77% sensitivity, and 79, 73 and 78% overall accuracy. These results were significantly better than those obtained with RI and PSV in US, which had no significant difference between different stages of early renal dysfunction. Conclusion: CEUS can improve the early diagnosis of renal dysfunction. DPI, A and AUC might be valuable quantitative indexes. B-170 15:21 Quantitative evaluation of contrast-enhanced ultrasonograhpy in the diagnosis of chronic ischemic renal disease in a dog model Y. Dong, W. Wang, H. Ding, C. Li; Shanghai/CN ([email protected]) Purpose: To prospectively test, in a dog model of chronic ischemic renal disease (CIRD), the hypothesis that real-time contrast-enhanced ultrasonography (CEUS) can quantitatively evaluate the perfusion changes of renal cortex in the early period. Methods and Materials: In this animal care and use committee-approved study, the model of CIRD was established in healthy dogs (10.0-12.0 kg, n = 5), by placing an Ameroid ring on the distal portion of the right renal artery through operation. CEUS was performed for the right kidney with an intravenous bolus injection of 0.6 ml SonoVue every 1 week after operation. The slope rate of elevation curve (A) and descending curve (A), area under curve (AUC), derived peak intensity (DPI) and time to peak (TTP) were measured in the renal cortex using QLab software (PHILIPS iU22). Comparisons between different stages were performed using random-effects regression. After 4-16 weeks of continuous observation, histopathologic examinations were performed. The sensitivity of CEUS was compared with the blood serum urea nitrogen (BUN) and serum creatinine (SCr) level. Results: With the progress of CIRD, the dogs showed decreased enhancement and delayed perfusion in the renal CEUS curve. The earliest significant changes happened 4 weeks after operation on DPI and TTP from (13.04 p 2.71) to (15.58 p 4.75) dB and (9.03 p 2.01) to (10.62 p 6.04) sec (P 0.05). Significant change happened 11 weeks later on BUN and SCr (P 0.05). Conclusion: In this dog test experiment, CEUS can display the perfusion changes of CIRD in the early period. 14:00 - 15:30 Room F2 Breast SS 302 Screening and diagnosis Moderators: R. Gruber; Vienna/AT R. Holland; Nijmegen/NL B-171 14:00 Mammography positioning and radiation dose J. Peters; Frankfurt/DE ([email protected]) Purpose: The ML view has been replaced by the MLO view because MLO positioning shows more of the axillary tail of the breast tissue than the ML view.In mammography screening programs radiation dose is an important issue. Thus we compared the dose required for MLO and ML views. Methods and Materials: In our breast center 38,800 women received mammographies between March 2007 until August 2008. 30,272 screening and 8,538 clinical mammographies were done. Thus 77,600 MLO views were obtained. In 520 cases additional ML views were necessary for needle localization of non-palpable lesions, preparation for vacuumbiopsies and identification of peudolesions caused by MLO-positioning. Mammographies were obtained with the full-field digital device by Sectra. Radiation dose required for MLO and ML views were compared. Results: Radiation dose applied in MLO views ranged between 0.420 and 0.110 mGy with an average of 0.646 mGy. In ML views the dose ranged between 0.33 and 0.82 mGy with an average of 0.495 mGy. Thus the ML view required a considerably lower radiation dose than the MLO view. Conclusion: Since MLO requires more radiation than ML-positioning mammographies are obtained with higher doses than necessary. Thus ML-positioning might be reconsidered. If the axillary tail is not included completely an additional MLO view may be necessary. But for the large number of women where the entire breast tissue is included in the ML view, exposure is minimized. In addition spatial orientation for surgeons and radiotherapists is more precise with ML-views. A B C D E F G H S177 Friday at 10 ml/s. Scanning parameters were 100 kV, 20-40 mAs, 0.5 s rotation time, 16 cm collimation, and 0.5 mm slice thickness for all dynamic scans. Patients were pre-oxygenated through a mask. All patients were imaged routinely before living kidney donation for complete renal evaluation. The study had ethics approval. Images were first registered for motion correction. ROIs were placed in the aorta as the reference and within 10 levels in each kidney. The maximum-slope technique was used for perfusion maps, Patlak-plot for calculation of renal clearance. Results were compared to renal scintigraphy, performed within 2 days. Results: All patients tolerated the scanning procedure well, including the 40 s breathhold for the first 10 scans. Image registration failed in 2 patients necessitating manual interaction. Perfusion images were colour-coded and showed little anatomical mismatch at the outer edges of the kidneys (1-3 mm). The CT clearance varied from scintigraphy between p27%, the correlation was 0.66, the average clearance in CT and scintigraphy were 91.4 and 103.5, respectively. Conclusion: CT perfusion based on 320-slice dynamic volume CT allows for calculation of renal clearance with good correlation to scintigraphy. Image registration appears to be crucial for motion correction. Scientific Sessions B-172 14:09 Digital workflow for mammography screening purposes in Denmark U. Anderrson; Helsingborg/SE ([email protected]) Purpose: To develop and fully utilise IT technology in a digital workflow to benefit mammography screening in Denmark. To improve booking and communication for participants and improved workflow productivity for clinicians, while fulfilling European guidelines for mammography double-blind reading. The project scope included the three regions of Sjealland, Hovedstaden and MidtJylland, representing more than two-thirds of the Danish population. Methods and Materials: Following a successful bid for Government funding, Ringsted Sygehus in the Sjaelland Region of Denmark initiated the development work for a digital workflow module for mammography screening. Other professionals from Hovedstaden and MidtJylland regions were invited to participate to understand how the community can scale and take advantage of a digital workflow. Data captured were input into a research programme, resulting in development of the solution. Results: A double-blind reading module for radiologists is running in a digital environment, fulfilling European guidelines. Productivity gains include remote reading capabilities, helping to utilise the shortage of expert mammography radiologists and an online portal that allows screening participants to directly cancel and reschedule appointments resulting in reduced administration. Conclusion: The efficiency of mammography screening workflow has improved with the identification of commonalities and proven efficiency gains between regions. The improvements in administration and productivity will support the Danish government’s strategy of full mammography screening across the country by the end of 2008. B-173 14:18 Screening with digital mammography: Has it increased our rate of biopsy for microcalcifications? J.M. Kerr, G. Hargaden, H.M. Fenlon, M.M. McNicholas, F.L. Flanagan; Dublin/IE Purpose: To determine the effect of introduction of digital mammography on recall rates, biopsy rates and benign biopsy rates for microcalcifications in a breast cancer screening programme. Methods and Materials: The BreastCheck (Irish National Breast Screening Programme) database for the period January 2000 to March 2008 was reviewed. The patients recalled to assessment for microcalcifications, those biopsied at assessment for microcalcifications and the biopsy outcome were identified for 2 groups, those who had analogue and digital screening mammographies. Comparison was made between the two groups in terms of recall rates and biopsy rates for microcalcifications, as well as the biopsy outcome. Results: 44.8 per 1000 patients screened in the analogue group and 36.7 per 1000 patients screened in the digital group were recalled to assessment. 7 per 1000 were recalled for microcalcifications in the analogue group and 8.1 per 1000 in the digital group. 5.1 biopsies were performed per 1000 screened in the analogue group and 5.9 per 1000 in the digital group. In the analogue group, there were 0.01 per 1000 B1, 2.16 per 1000 B2, 0.71 per 1000 B3, 0.15 per 1000 B4 and 2 per 1000 B5 lesions. In the digital group there were 0 B1, 2.74 per 1000 B2, 0.56 per 1000 B3, 0.28 per 1000 B4 and 2.35 per 1000 B5. Conclusion: The proportion of patients recalled to assessment for microcalcifications is higher in patients screened with digital mammography. The number of biopsies for microcalcifications is also higher. As well as identifying more malignant microcalcifications with digital screening, the benign biopsy rate is increased. B-174 14:27 Screen detected breast cancers and computer aided detection (CAD) prompting in a multicentre prospective evaluation of CAD in the UK breast screening programme F.J . Gilbert1, J. James2, M.G. Wallis3, C.R.M. Boggis4, S.M. Astley4, M.G.C. Gillan1, O.F. Agbaje5, S.W. Duffy5; 1Aberdeen/UK, 2Nottingham/UK, 3 Cambridge/UK, 4Manchester/UK, 5London/UK ([email protected]) Purpose: Computer aided detection (CAD) systems have been developed that use software-based detection algorithms to attract the film reader’s attention to potentially abnormal features on a mammogram. Data from CADET II (a multicentre randomised evaluation of single reading with CAD and double reading in the UK breast screening programme) has been analysed to compare reader recall decisions in relation to the accuracy of CAD prompting. Methods and Materials: Mammograms from 28,204 women attending routine two-view screening mammography were independently double read (DR) and separately single read using CAD (SRCAD). Two experienced radiologists retrospectively reviewed the 227 screen-detected cancer cases prior mammograms S178 A B C D E F G F H and pathology reports recording the number and location of any CAD marks in relation to the tumour location. Results: Of the 227 cancers detected complete data were available for 200 (88%) cases. The cancer was marked by CAD in 175/200 (80%) of cases. There were 57 discordant recall decisions by the two reading regimes. Complete prompt data were available in 50 cases. The CAD prompt was correctly placed in 20/25 cases recalled by SRCAD and 17/25 cases where SRCAD did not recall (P = 0.52). Tumour characteristics were similar in both groups although slightly more masses and calcifications were recalled by SRCAD than not recalled (23/28) compared to 19/29 (P = 0.23). Conclusion: This suggests that while the single reader is being influenced by CAD, further work is required to understand why prompted tumours are being ignored. B-175 14:36 Evaluation of the performance of independent expert reading after double reading: Is there a higher detection rate of breast cancer in an analysis of 102,744 diagnostic processes? F.K.W. Schaefer, A. Katalinic, P.J. SchГ¤fer, B.M. Order, C. Wefelnberg, W. Jonat, I. Schreer; Kiel/DE ([email protected]) Purpose: To determine the performance of expert reading in symptomatic or women at risk. All patients were examined in the project вЂ�quality assurance in breast cancer diagnosis’ (the QuaMaDi Project). In Schleswig-Holstein/Germany this processorientated and comprehensive quality management project was implemented to improve the standard of breast cancer diagnosis. Methods and Materials: A prospective cohort between 2001 and 2005 with a total of 59,514 patients and 102,744 mammograms was initiated. For independent second reading, the images of mammography p ultrasound documents were sent to a second radiologist. If results were scored as BI-RADS 4 or 5 and in case of dissent between BI-RADS1/2 vs 3 vs 4/5, the image materials were sent to expert reading for arbitration purposes. Abnormalities were defined positive, if biopsy findings revealed malignancy and negative if biopsy findings or all examinations turned out to be benign. Results: According to the study protocol 24,470 cases (23.8%) of all radiological examinations were third-read by expert reading at the reference centre. Expert reading revealed 50 additional cancers (50/1019, 70% by US, 30% by mammography) out of 62,006 cases. That implies 5.2% extra detected cancers by expert reading (2/1000 examinations). Conclusion: Supplementary expert reading resulted in a significant breast cancer detection rate increase of 5.2%. B-176 14:45 Sensitivity of a computer-aided detection system (CAD) applied to full field digital mammography (FFDM) based on breast density C. Romero, I. Herrera, C. Varela, A. Almenar, M. Garcia Hidalgo, J. Pinto; Toledo/ES ([email protected]) Purpose: To show the results of a CAD system (R2 Technology, version 5.4) applied to digital mammograms according to breast density in a diagnostic setting. Methods and Materials: This is a 1-year prospective study run by two radiologists’ expert on breast imaging (8 and 4 years of experience). They did single reading of 9000 FFDM (MAMMOMATВ® Novation DR Siemens, Germany) cases, which were reported including the BI-RADS assessment code and the mammographic density (BI-RADS 1-4). In addition, any change in opinion due to CAD results was registered. The BI-RADS 4 and 5 were biopsied. All cancers underwent MRI and histopathology confirmation. Results: Out of the 9,000 cases, 138 were cancers. The CAD system correctly marked 118 (sensitivity 86.6%, 95% CI = 81.1-90.8), and missed 20 (14.5%). The sensitivity of the CAD system based on breast density was overall 1: 91.2%; 2: 93%; 3: 82%; and 4: 80.2%. Sensitivity for microcalcifications was 1: 100%; 2: 100%; 3: 92.3%; 4: 95%. Sensitivity for mass, asymmetry, and architectural distortion was1: 93.3%; 2: 87.5%; 3: 78.8%; 4: 63.6%. The false-positive rate was less than 2 per case. 8 to 18 months follow-up were done for detection of new false-negative results. Conclusion: Breast density did not have a significant effect on the detection of microcalcifications but did on the detection of masses, asymmetry, and architectural distortion. Based on our results, it may be possible to do pre-screening in BI-RADS 1 and 2 density cases. We will complete the study by doing a 2-year follow-up to determine any additional false-negative results. Scientific Sessions B-177 14:54 Purpose: To prospectively determine frequency, pathology and causes of false negative assessment (FNA) in women recalled for suspicious screening mammography. Methods and Materials: We included all 290,943 screening mammograms of women aged 50-75 years, who underwent biennial screening mammography between January 1, 1995 and January 1, 2006 in the Southern Netherlands. Radiologic, pathologic and surgical data were collected of all 3513 recalled women during 2-year follow-up. Tumor stages of false negatively assessed breast cancers, defined as cancers diagnosed more than 3 months following recall, were compared with those of cancers diagnosed within 3 months following recall and with interval cancers. Results: FNA occurred in 6.5% (97/1503) of all screen-detected cancers. FNA cases comprised more ductal cancers in situ (26.8%) than did cancers diagnosed 3 months after recall (15.5%, p=0.004) or interval cancers (3.7%, p 0.001). Invasive FNA cancers were smaller than interval cancers (T1a-c, 87.3 vs. 46.4%; p 0.001) and less often showed axillary lymph node metastases (22.5 vs 48.2%; p 0.001). FNA percentages significantly varied between hospitals that had evaluated at least 500 recalled women each (range: 5.0% (20/401 cancers) to 9.1% (29/320 cancers; p=0.03)). Improper classification of cancers at diagnostic mammography was the major determinant of FNA in these hospitals and comprised 64.4% of false negative assessments. Conclusion: 6.5% of recalled women experienced a delay in breast cancer diagnosis, with significant performance variations between hospitals. Although tumor stages of FNA cases are more favourable than those of cancers without diagnostic delay or interval cancers, FNA may negatively affect long-term outcome. B-178 15:03 Is CAD effective in detecting high risk breast lesions? I. Leichter1, R. Lederman1, N. Merlet1, E. Ratner1, A. Manevitch1, Z. Gallimidi2, A. Heyman-Reiss2; 1Jerusalem/IL, 2Haifa/IL ([email protected]) Purpose: To evaluate the detection sensitivity of a CAD device on high-risk lesions, which should be marked in screening mammography, since most high-risk lesions, especially those with atypia must be surgically excised. Methods and Materials: 154 pathology-proven FFDM malignant cases (113 invasive, 41 non-invasive), 19 cases with high-risk lesions (12 ADH, 7 LS) and 2706 normal cases were culled retrospectively, in a consecutive manner, from 6 screening facilities. A non-blinded radiologist recorded, for each malignant and high-risk case, the location of the biopsied finding. All cases were run on a prototype CAD device (Siemens) that detected and marked suspicious findings on the images. Detection was assessed by comparing each CAD mark to the biopsied finding. The CAD performance for the high-risk cases was compared with that of the malignant cases. Each CAD mark on normal cases was considered false. Results: The overall sensitivity of CAD for high-risk cases was 84.21% [95% CI: (66.15, 100%)]. Of the high-risk cases, the ADH lesions yielded a detection sensitivity of 83.33%, while for LS lesions it was 85.71%. The CAD sensitivity for highrisk lesions was not significantly different from the sensitivity for invasive lesions. The sensitivity for non-invasive lesions was significantly higher (p 0.06) than for high-risk lesions. The number of false marks per case marked on the 2706 normal cases was 1.24 [95% CI: (1.177, 1.303)]. Conclusion: The CAD performance for high-risk lesions is comparable to malignant lesions, allowing CAD to assist the radiologist in identifying these lesions, most of which require excisional biopsy. B-179 15:12 Comparison of the performance of different professional groups of film readers using computer-aided detection (CAD) in the CADET II trial M.G. Wallis1, J. James2, C.R.M. Boggis3, O.F. Agbaje4, M.G.C. Gillan5, S.M. Astley3, S.W. Duffy4, F.J. Gilbert5; 1Cambridge/UK, 2Nottingham/UK, 3 Manchester/UK, 4London/UK, 5Aberdeen/UK ([email protected]) Purpose: Double reading of screening mammograms is more sensitive for the detection of small breast cancers, but there is a shortage of trained radiologist film readers. The CADET II trial-demonstrated single read supplemented by CAD (SRCAD) had an equivalent cancer detection as double read (DR), but with an increase in the recall rate. Data from the trial provided an opportunity to compare the performance of different professional groups of film readers. Methods and Materials: The trial was based at three UK screening centres and involved a total of 27 film reading personnel: 15 consultant radiologists; 4 breast clinicians or registrar radiologists; 8 advanced practitioner radiographers. Mammograms from 28,204 women attending routine two-view screening mammography were double read (DR) and single read using CAD (SRCAD). Results: The SRCAD reader was significantly more likely to recommend recall than either of the DR readers (P 0.001). For the first DR reader, recall rates were significantly (P 0.001) higher for radiographers than for consultant radiologists (5.1% vs 3.4%). The breast clinicians/registrars had a similar recall rate as the consultant radiologists (3.7%). For the second DR reader, the radiographers and breast clinicians had significantly (P = 0.04) lower rates of recall than the consultant radiologists (2.9 and 2.8% vs 3.4%). For SRCAD, the breast clinicians/registrar radiologists were significantly (P = 0.002) more likely to recommend recall than either the radiologists or the radiographers (5.9 vs 3.8% and 3.9%). Conclusion: This suggests that SCRAD using radiographers could be a viable alternative to the current double reading practice where at least one reader is medically trained. B-180 15:21 Triple negative breast cancer: Clinical presentation and multimodality imaging characteristics O. Woo, S. Huh, A. Yi, Y. Kim, K. Cho, H. Yong, B. Seo, E.-Y. Kang; Seoul/KR ([email protected]) Purpose: Triple-negative breast cancer (TNBC) is defined by the lack of expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2). In this study, we evaluated the clinical presentations and multimodality imaging findings of TNBC. Methods and Materials: The medical records of patients who underwent surgical operations for primary breast cancer at our institute were retrospectively reviewed. Patients received mammography (n = 58), breast ultrasound (n = 58) or MR imaging (n = 38). Clinical presentations, pathologic results and staging were reviewed and the multimodality imaging findings were analyzed by two radiologists in consensus. Results: Among 390 breast cancer patients, 58 (15%) were diagnosed with TNBC. The mean lesion size was 3.7 cm (range, 1.1- 10.7 cm). Of 58, 47 (81%) were symptomatic, while 11/58 (19%) were detected during screening mammography or ultrasound. On mammography, a round or lobular shape (45%), circumscribed margin (40%) and absence of microcalcifications (89%) were the main findings. On ultrasound, a round or lobular shape (48%), circumscribed margin (43%) and hypoechogenecity (96%) were the prominent findings. On MR imaging, although 16/38 (42%) showed benign morphologic characteristics, 32/38 (84%) presented type III wash-out dynamic enhancement pattern. Of the 58 TNBC, 54 (93%) were invasive cancers and 4 were DCIS. Regarding histologic grading, high-grade carcinomas were found in 52/58 (89%) of the TNBC. Conclusion: TNBC more often present as high-grade interval cancers that show benign morphologic appearances on multimodality imaging. Knowledge of the characteristics of TNBC may provide earlier detection and proper diagnosis. 14:00 - 15:30 Room G/H Head and Neck SS 308 New techniques in tumor management Moderators: B. Lombay; Miskolc/HU P. PiГ±ero; Sevilla/ES B-181 14:00 Additional value of DCE-CT for combined FDG-PET/CT in the outcome prediction of patients with head and neck tumors A. Abramyuk1, K. ZГ¶phel1, S. Tokalov1, U. Haberland2, E. Klotz2, T. Herrmann1, M. Baumann1, N. Abolmaali1; 1Dresden/DE, 2Forchheim/DE ([email protected]) Purpose: The higher FDG uptake measured using PET in head and neck tumors (HNT) is associated with shorter survival. At the same time, the tumor blood volume (TBV), which could be measured with dynamic contrast-enhanced (DCE) CT, is also an important characteristic influencing both radio- and chemotherapy outcome. The attempt of this work was to clarify whether implementation of DCE- A B C D E F G H S179 Friday Delayed diagnosis of breast cancer in women recalled for suspicious screening mammography L.S.F. Yo1, L.E.M. Duijm1, J.H. Groenewoud2, H.J. de Koning2, J. Coebergh2, M.J.H.H. Hooijen3, L.V. van de Poll-Fransse1; 1Eindhoven/NL, 2Rotterdam/NL, 3 Geldrop/NL ([email protected]) Scientific Sessions CT in pre-therapeutical FDG-PET/CT protocol could be of clinical relevance in patients with HNT. Methods and Materials: A total of 10 consecutive patients with histologically proven HNT had been included into the study. Patients underwent FDG-PET/CT with DCECT component before treatment using a combined PET/CT scanner Biograph 16 (Siemens) and a double head power injector Injectron CT 2 (MedTron). TBV was determined using modified Patlak analysis with a pixel-based prototype software (Siemens). Follow-up time was 24 months for all surviving patients. Results: Using FDG-PET/CT, it was shown that three patients with low FDG uptake (SUVmax: 8 p 1) and five to seven patients with higher FDG uptake (SUVmax:15 p 4, P = 0.004) were free of local recurrence. Using DCE-CT, it was found that all patients with homogeneous tumor blood supply and high TBV (9.3 p 3.9 ml/100 ml tissue) were without local recurrence, while two of three patients with heterogeneous tumor blood supply and regions of low TBV (3.2 p 1.3 ml/100 ml tissue, P = 0.06) within the tumor died during follow-up because of tumor recurrence. Conclusion: According to our initial data, DCE-CT might possibly better predict outcome of patients with HNT than FDG-PET/CT. The data justify initiating a more extensive prospective study. B-182 14:09 Quantitative modifications of TNM-staging and therapeutic intent by 18 FDG-PET/CT in patients scheduled for radiation therapy suffering from head and neck-cancer S. Kvasny, A. Abramyuk, A. Koch, K. Zoephel, S. Appold, N. Abolmaali; Dresden/DE ([email protected]) Purpose: To evaluate the modifications by 18 FDG-PET/CT on conventional pretreatment staging in patients suffering from head&neck-cancer (HNC)scheduled for radiation therapy (RT). Methods and Materials: 102 consecutive patients scheduled for RT suffering from HNC who received no previous treatment underwent conventional morphologic staging using CT and MRI and a subsequent 18 FDG-PET/CT staging. Pre-PET/ CT staging was done on an outpatient basis, PET/CT staging was done by three board certified specialists (diagnostic radiologist, nuclear medicine physician, radiation oncologist) in consensus. Results: T-, N- and M-stage was increased in 10%, 8%, and 13%, reduced in 35%, 26%, and 1%, and remained unchanged in 55%, 66%, and 86%, respectively. The clinical stage was increased in 8%, reduced in 16%, and not changed in 76% of patients. Statistically, there was a significant improvement of T- and N-stage (p=0.002; p=0.0006) and worsening of M-stage (p=0.001). The clinical stage was not significantly modified d (p=0.1). As a result therapeutic intent was changed in 12% of the patients from curative to palliative, 2% of patients went from palliative to curative intent. In 86% therapeutic intention remained unchanged. Overall, FDGPET/CT reduced radiation therapy volumes mainly in patients in which the T- and N-stage was changed and modified the therapeutic intent in patients in which the M-stage was changed. Conclusion: 18 FDG-PET/CT in HNC-patients is advantageous to decide the therapeutic intent before RT-planning in 14% of the patients. Additionally, side effects of RT are reduced by shrinkage of RT-volumes. Studies on the prognostic relevance for these patients are ongoing. B-183 14:18 Modern imaging of head and neck tumours: 3 T-MRI, DWI, PET-CT J. FrГјhwald-Pallamar, J.M. Patsch, A. Herneth, M. Formanek, C. Czerny; Vienna/AT ([email protected]) Purpose: To assess the additional information of diffusion-weighted imaging (DWI) and PET-CT in the preoperative evaluation of patients with biopsy-verified ENT malignancy. Methods and Materials: A total of 13 patients with proven ENT malignancies, who underwent conventional MR imaging, DWI and PET-CT for preoperative evaluation were retrospectively analysed. MR imaging at 3 Tesla (Philips, Archiva) with a dedicated head and neck coil included coronal STIR, axial STIR and axial T1-weighted sequences before and after i.v. contrast media application. Additional two different types of diffusion-weighted sequences were measured: in the sagittal plane DWI_MSh FH and in the axial plane DWIBS was used (b-value: 0-800), and the ADC was calculated. An 18-FDG-PET-CT was performed on a Siemens biograph scanner after the i.v. application of CT contrast material and 18-FDG-PET tracer to acquire additional information as pathological lymph nodes outside the MR scanning range, metastasis and second primary tumours (as it often occurs in patients with ENT squamous cell carcinomas). Results: The final histopathological results included squamous cell carcinoma, sarcoma, adenocarcinoma and metastasis. In most of the cases, PET-CT had a S180 A B C D E F G F H higher sensitivity and specificity in detecting lymph node metastasis because of a higher glucose metabolism. In one case of an angiosarcoma, neither the tumour nor the lymph node metastasis showed an increased tracer uptake in FDG-PETCT, whereas in the DWI sequences the pathologic lymph node could be clearly diagnosed. Conclusion: DWI offers a higher diagnostic accuracy than conventional MRI sequences in detecting lymph node metastasis, especially in tumours that are negative on PET-CT. B-184 14:27 Dynamic contrast-enhanced MR imaging: A reliable diagnostic tool for recurrent head and neck tumors E. Kamel, P. Pasche, R. Meuli, P. Hauser, I. Borchardt, P. Schnyder, B. Duvoisin; Lausanne/CH ([email protected]) Purpose: To investigate the role of Dynamic Contrast-Enhanced MR Imaging (DCE-MRI) in the follow-up of patients with head and neck tumors. Methods and Materials: Twenty-seven patients were recruited. DCE-MRI was performed as a part of regular posttherapy follow-up (n = 20) or for clinical suspicion of local disease recurrence (n = 7). Axial dynamic T1-weighted fat sat sequences were performed in a 3-T MR scanner for a total duration of 10 minutes after contrast administration. An operator-defined region of interest was placed in the maximal enhancement area (s) of the tumor bed. A time-intensity curve was constructed. The time to maximal enhancement (Tmax), enhancement ratio at 3 min (ER3 min), and washout ratio at 10 min (WR10 min) were measured. Per-lesion DCE-MRI findings were correlated with histologic analysis or with clinical and radiological follow-up. Results: There was a significant difference between Tmax, ER3 min and WR10 min of recurrent lesions and those of posttherapy tissue remodeling (2.2 min, 19%, and 20% vs. 8.3 min, 12%, and 6%, P 0.05). Among 12 recurrent lesions in 9 patients, DCE-MRI detected 11/12 (91%) of these foci. One false negative result was due to microscopic disease residue. Two radionecrotic lesions were responsible for false positive DCE-MRI results in 2 patients. In the remaining 16 patients, true negative DCE-MRI findings were confirmed. Accordingly, the sensitivity, specificity, and accuracy of DCE-MRI were 91%, 89% and 90%, respectively. Conclusion: DCE-MRI can be integrated in the diagnostic work-up of patients with or without clinical or radiological suspicion of recurrent head and neck tumors. B-185 14:36 Outcome prediction after surgery and chemoradiation of squamous cell carcinoma in the upper aerodigestive tract: Comparison of perfusion CT versus tumor volume S. Bisdas1, I. Burck2, S.K. Anand3, T. Day3, G. Glavina4, M.G. Mack2, Z. Rumboldt3; 1TГјbingen/DE, 2Frankfurt a. Main/DE, 3Charleston, SC/US, 4 Split/HR ([email protected]) Purpose: To examine whether perfusion CT (PCT) may predict outcome in patients with squamous cell carcinoma (SCCA) of the upper aerodigestive tract after surgical excision with chemoradiation. Methods and Materials: Twenty-six patients with SCCA were examined before treatment. The primary site was oral cavity in 6, oropharynx in 7, and hypopharynx in 8 patients; there were eleven T2, six T3 and four T4 tumors. The PCT data was processed to obtain blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS). Tumor volume was also calculated. Follow-up was performed with PET/CT and endoscopy. Pearson correlation coefficient was used for comparison between the subgroups. A regression model was constructed to predict recurrence based on the following predictors: age, gender, tumor (T) and nodal (N) stage, tumor volume, and PCT parameters. Results: BFmean, BFmax, BVmean, BVmax, MTTmean, PSmean, and PSmax values were significantly different between patients with and without tumor recurrence (0.0001p 0.04). T stage, tumor volume, N stage, BFmax, BVmax, MTTmean, and radiation dose (p 0.001) were independent predictors for recurrence. Cox proportional hazards model for tumor recurrence revealed significantly increased risk with high tumor volume (p=0.00001, relative risk [RR] 7.1), low PSmean (p=0.0001, RR 14), and low BFmax (p=0.002, RR 5.6). Conclusion: PCT parameters have a predictive role in patients with SCCA treated with surgical surgery and adjuvant chemoradiation. Scientific Sessions B-186 14:45 Purpose: The aim was to determine the diagnostic accuracy and additional value of diffusion-weighted imaging (DWI) for detection of malignant lymph nodes in head and neck squamous cell carcinoma (HNSCC). Methods and Materials: A total of 219 lymph nodes, predominantly smaller than 10 mm (95.4%), in 16 consecutive patients were evaluated on MRI (1.5 Tesla). Lymph nodes were evaluated for maximum short axial diameter, morphological criteria and apparent diffusion coefficient (ADC) values (b = 0 and b = 1,000 sec/ mm2). Diagnostic parameters, sensitivity and specificity with diagnostic odds ratio (DOR), were compared for the various MRI criteria. The AUCs of ROC curves were derived from multivariate logistic regression models, which included different sets of MRI criteria. The AUCs were compared to evaluate the added value of ADC to the other MRI criteria. Results: The optimal ADC threshold was 1.0 Г— 10-3 mm2/sec. Using this value as the cut-off point, sensitivity and specificity were 92.3 and 83.9%, respectively. When used in combination with size and morphological criteria, ADC value 1.0 Г— 10-3 mm2/sec was the strongest predictor of the presence of metastasis (DOR = 97.6; 95% CI: 97-982). A model that added ADC values to the other MRI criteria performed significantly better than a model without ADC values: AUC = 0.98 versus AUC = 0.91 (P = 0.036). Conclusion: In this study, with predominantly small lymph nodes, the ADC criterion is the strongest independent predictor of the presence of metastasis, followed by the border criterion. The use of ADC values in combination with other MRI criteria can significantly improve the discrimination between cervical lymph nodes with and without metastasis. B-188 14:54 Differentiation of primary parotid gland tumors: Does a combination of diffusion-weighted echo-planar MRI and magnetization transfer imaging offer diagnostic improvement? C.R. Habermann, C. Arndt, J. Graessner, F. Reitmeier, M. Jaehne, G. Adam; Hamburg/DE ([email protected]) Purpose: To investigate the potential of diffusion-weighted (DW) echo-planar imaging (EPI) in combination with magnetization transfer imaging in differentiating primary parotid gland tumors. Methods and Materials: A total of 145 consecutive patients with suspected primary tumor of the parotid gland were prospectively examined. A DW EPI sequence and a single-slice T1-weighted GRE sequence in in-phase and opposed-phase technique prior and post 1 kHz off-resonance pulse were acquired. ADC maps and MT images were digitally transferred to MRIcro and evaluated with a manually placed irregular region of interest (ROI) containing the entire tumor. For comparison of the results, the two-tailed Student’s t test with Bonferroni correction for multiple testing was used, based on the mean ADC values for each patient. Results: In 129 patients, 14 different subtypes of primary neoplasms of the parotid glands could be verified histologically. Based on the ADC values, pleomorphic adenomas could be differentiated from all entities (P 0.001) except myoepithelial adenomas (P = 0.054). Using MTR, these two entities could not be discriminated as well (P = 0.394). DW imaging failed to differentiate Warthin tumors from mucoepidermoid carcinomas, acinic cell carcinomas and basal cell adenomas (P = 0.094 to 0.604), whereas MTI was able to differentiate Warthin tumors and basal cell adenomas (P = 0.004). DW imaging failed in differentiating myoepithelial adenomas and mucoepidermoid carcinomas from basal cell adenocarcinomas (P = 0.082; 0.569), whereas MTI was able to differentiate these entities (P = 0.032; 0.014). Conclusion: DW imaging has a potential in differentiating subtypes of parotid gland tumors. Combining this technique with MTI improves the noninvasive approach. B-189 15:03 Can quantitative diffusion-weighted MRI differentiate benign and malignant cold thyroid nodules? Initial results in 25 patients C. Schueller-Weidekamm, G. Schueller-Weidekamm, C. Czerny, A. Herneth; Vienna/AT ([email protected]) Purpose: The characterization of cold nodules of the thyroid gland is mandatory as approximately 20% of these nodules are of malignant origin. The purpose of this study was to evaluate the dignity of cold thyroid nodules using quantitative diffusion-weighted MRI (DWI). Methods and Materials: In 25 patients with cold nodules on scintigraphy and suspicious findings at fine-needle aspiration, thyroid carcinoma was suspected. In these patients, cold nodules and the normal parenchyma of the contralateral thyroid lobe were prospectively investigated with quantitative DWI (echo-planar imaging sequence; maximum b-value 800 sec/mm2) prior to surgery. The differences in the mean apparent diffusion coefficient (ADC) values in benign and malignant nodules were tested by using a Mann-Whitney-U test. Results: Histologically, there were 20 carcinomas with a minimum size of 8 mm and five adenomas. The mean ADC values (in 10-3 mm2/sec) differed significantly between carcinoma, adenoma, and normal parenchyma (P 0.05). The ranges (95% confidence interval) of the ADC values for carcinoma (2.43-3.037), adenoma (1.626-2.233), and normal parenchyma (1.253-1.602) showed no overlap. When an ADC value of 2.25 or higher was used for predicting malignancy, the highest accuracy of 88%, with 85% sensitivity and 100% specificity, was obtained. Conclusion: Quantitative DWI seems to be a feasible tool by which to differentiate thyroid carcinomas from adenomas; however, further studies are required including larger number of patients to confirm our results. B-190 15:12 Interobserver agreement at the malignant thyroid nodules with conventional ultrasound (US) and US elastography: Prospective study S. Park; Incheon/KR ([email protected]) Purpose: To investigate interobserver agreement at the malignant thyroid nodules with conventional B-mode US and real-time free hand US elastography. Methods and Materials: Between December 2007 and February 2008, 42 patients (19-73 years; 45.0p 12.2 years) with 52 thyroid nodules were examined with conventional B-mode US and real-time free hand US elastography. All the patients were scheduled to undergo thyroid surgery due to thyroid nodule having been proven to be malignant on aspiration cytology. Three experienced, board certified radiologists independently performed conventional US and elastography and analyzed US images. Analysis in conventional US included composition (solid, cyst, mixed-echoic, sponge), nodular echogenicity (hyperechoic, isoechoic, hypoechoic, marked hypoechoic), margin (well-circumscribed, microlobulated or irregular), calcification (micro, macro, negative, mixed), shape (parallel, non-parallel) and final assessment (cyst, probably benign, low suspicious, suspicious). Ueno classification and odds ratio were made by using US elastography. Interobserver agreement was evaluated with Spearman correlation analysis except the area ratio (using Pearson correlation analysis). Results: Stastistically significant (p .05) concordance between 3 radiologists was found for most US features except for nodular echogenicity and margin of thyroid nodules on conventional US. The highest value of concordance was achieved in composition, followed by underlying parenchymal echogenicity, shape, calcification and final assessment. The least concordant finding was margin and nodular echogenicity on conventional US. However, there was no stastistically significant concordance in Ueno classification and area ratio on elastography. Conclusion: Conventional US made stastistically significant concordance between radiologists in most of US features; however, US elastography did not make reliable interobserver agreement at malignant thyroid nodule. 14:00 - 15:30 Room I Vascular SS 315 Magnetic resonance angiography Moderators: V. Iaccarino; Naples/IT A. TГіth; Budapest/HU B-191 14:00 Intraindividual comparison of time-of-flight (TOF)- and phase-contrast angiography (PCA) with time-resolving 4D-keyhole angiography of cerebral vessels B. Buerke, T. Niederstadt, C. Bremer, W. Heindel, B. Tombach, T. Allkemper; MГјnster/DE Purpose: To investigate the feasibility of high-resolution four-dimensional (4D) CE-MRA of the brain using a combination of keyhole data acquisition and parallel imaging (SENSE) compared to non-enhanced techniques (TOF- and PC-MRA). Methods and Materials: A total of 46 patients suspected with intracranial vascular pathologies were examined on a 1.5 T scanner (Intera 1.5, Philips, The Netherlands) with the help of a SENSE-capable head coil. Contrast-enhanced MRA of A B C D E F G H S181 Friday Diagnostic accuracy of diffusion-weighted imaging for discrimination of malignant lymph nodes in head and neck squamous cell carcinoma R.B.J. de Bondt1, M.C. Hoeberigs1, P.J. Nelemans1, W.M.L.L. Deserno2, C. Peutz-Kootstra1, B. Kremer1, R.G.H. Beets-Tan 1; 1Maastricht/NL, 2Almelo/NL ([email protected]) Scientific Sessions the intracranial vessels was performed with 1M Gadobutrol (0.1 mmol/kg bw, flow rate 2 cc/sec, followed by 20 ml saline flush, fixed delay 10 sec) using a 4D-keyhole acquisition technique (temporal resolution 7.3 sec, spatial resolution 0.39 x 0.39 x 0.7 mm). Comparative TOF-MRA (voxel size 0.31 x 0.31 x 0.70 mm) and PCA (0.90 x 0.90 x 0.80 mm) were performed in the same session. Qualitative evaluation was performed by two experienced radiologists with regard to vessel contrast, venous overlay and overall image quality. Quantitative evaluation included SNR and CNR measurements in arterial and venous intracranial vessels. Results: The high temporal and spatial resolution of the 4D-keyhole acquisition technique enabled proper discrimination of arterial and venous vessel enhancement in 40/46 patients, providing an excellent image quality in most of the cases (38/46). Compared to non-enhanced techniques, the diagnostic impact of the 4D-keyhole technique was significantly higher due to discrimination of arterial and venous vessels. Furthermore, its total acquisition time was significantly shorter (4D-keyhole:63 sec,TOF-MRA: 6 min 17 sec, PCA: 8 min 18 sec). Quantitative analysis revealed comparable SNR and CNR values of keyhole, TOF- and PC-MRA data sets. Conclusion: The 4D-keyhole CE-MRA of the intracranial vessels is a robust diagnostic imaging tool that enables proper discrimination of the arterial and venous vessels within a total acquisition time of 63 sec, offering the potential to replace TOF- and PC-angiography. B-192 14:09 Determination of the optimal keyhole percentage for time-resolved, highresolution 3D keyhole CE-MRA: Results of an experimental study B. Buerke1, C. Bremer1, D. Maintz1, H. Kooijman2, B. Tombach1, W. Heindel1, T. Allkemper1; 1MГјnster/DE, 2Hamburg/DE Purpose: To experimentally determine the optimal keyhole-percentage (ratio between the central, dynamic and the peripheral, static part of k-space) for timeresolved, 3D CE-MR angiography using the CENTRA keyhole technique combined with parallel imaging (SENSE). Methods and Materials: Plastic tubes with diameters of 2; 5; 7; 9; 13; 15 mm were embedded in an agarose gel. Saline solution was pumped through these tubes with a pulsatile flow (450 ml/s,70 BPM) to simulate physiological conditions. Timeresolved 3D-keyhole CE-MRA scans were performed on a 1.5 T clinical imaging system (Gyroscan InteraВ®, Philips Medical Systems, The Netherlands) immediately after manual injection of 2 ml 1M GadobutrolВ® (Bayer Schering Pharma, Berlin, Germany). CE-MRA was repeated using different keyhole percentages of 6; 9; 14; 18; and 27% (temporal resolution: 1.3 s; 2 s; 3.1s; 3.9 s; 5.9 s) at a constant spatial resolution of 0.39x0.39x0.7 mm. Qualitative evaluation was performed by two experienced radiologists with regard to tube delineation, artifacts, and image contrast. Spatial accuracy was quantitatively assessed by measuring the apparent MRA tube diameter and comparing it to the genuine diameter. Results: The spatial accuracy decreased with increasing temporal resolution. Data sets acquired with keyhole percentages 14% suffered from severe pulsation artifacts, image blurring and insufficient spatial accuracy due to apparently increased tube diameters, especially for smaller tube diameters 5 mm. None of these effects was noticeable for data sets acquired with keyhole percentages r14%. Best image quality and highest spatial accuracy was observed for the lowest temporal resolution (keyhole percentage 27%). Conclusion: To guarantee for optimal spatial accuracy, temporal resolution, and image quality, time-resolved, high-resolution 3D keyhole CE-MRA data sets should be acquired with a keyhole percentage of 14-18%. B-193 14:18 Pre-surgical localisation of the artery of Adamkiewicz with time-resolved MRA at 3.0 T T.A. Bley, C. Duffek, C. Francois, M. Schiebler, T. Grist, S. Reeder; Madison, WI/US ([email protected]) Purpose: Patients undergoing thoracic aortic aneurysm (TAA) repair are at risk of paraplegia resulting from injury to the great radiculomedullary artery, “artery of Adamkiewicz” (AOA). Visualization of the AOA is challenging because this artery is 0.5 mm in diameter and its origin is highly variable. Preoperative visualization for surgical planning may be helpful to avoid paralysis. The purpose of this work was to use time-resolved MRA for visualization of the artery of Adamkiewicz at 3 T. Methods and Materials: A total of 55 patients were scanned on a 3.0 T scanner (HDx, TwinSpeed, GE) using time-resolved MR. Imaging parameters included: sagittal acquisition from T7 to L2, TR/TE = 4.4/1.7 ms, fractional TE, “whole” gradient mode, flip = 23o, BW = p50 kHz, FOV = 24 x 17 cm, slice = 1.4 mm, 256 x 256 x 54 matrix and 12 phases. True spatial resolution was 0.9 x 0.9 x 1.4 mm3, zero-filled to 0.5 x 0.5 x 0.7 mm3. Effective temporal resolution was 12.0 s; 0.2 mmol/kg of gadobenate dimeglumine (Bracco, Princeton). S182 A B C D E F G F H Results: Excellent visualization of the AOA was achieved in over 85% of cases. Utilizing time-resolved imaging, the AOA could be discerned from the anterior spinal vein that had the strongest opacification in later time phases of the timeresolved MRA. Conclusion: Time-resolved imaging is needed because timing of the arterial phase is difficult in the presence of large aneurysms. Arterial phases were achieved that help to distinguish the ASA from the anterior spinal vein, which has a similar course and can be confused with the anterior spinal artery. High spatial resolution imaging at 3.0 T using a dedicated spine coil, double dose contrast and nitroglycerine were steps taken to maximize visualization of the AOA. B-194 14:27 A total atherosclerotic score for whole-body MRA is related to traditional cardiovascular risk factors, IMT and manifest cardiovascular disease T. Hansen1, H. AhlstrГ¶m1, J. WikstrГ¶m1, L. Lind1, L. Johansson2; 1Uppsala/SE, 2 MГ¶lndal/SE ([email protected]) Purpose: To create a scoring system for whole body magnetic resonance angiography (WBMRA) that allows estimation of atherosclerotic-induced luminal narrowing in the arterial tree and to determine whether the traditional cardiovascular (CV) risk factors included in the Framingham risk score (FRS), intima media thickness (IMT) and manifest CV disease were related to the total atherosclerotic score (TAS) in an elderly population. Methods and Materials: A total of 306 subjects aged 70 were recruited from the general population and underwent WBMRA with a clinical 1.5 T scanner (Gyroscan Intera, Philips Medical system) and with administration of i.v. injection of 40 ml gadodiamide (Omniscan, GE Healthcare). The arterial tree was assessed according to its degree of stenosis or occlusion and a TAS was created. The IMT were measured in the common carotid artery with ultrasound. Results: FRS correlated with TAS (r = 0.30, P 0.0001). Of the parameters included in the FRS, male gender (P 0.0001), systolic blood pressure (P = 0.0002), cigarette pack years (P = 0.0008) and HDL cholesterol (P = 0.008) contributed to the significance, while blood glucose and LDL cholesterol did not. The IMT were correlated to TAS (P 0.0001). The group with CV disease had a significantly higher mean TAS value (38.8) than the group without CV disease (23.3; P = 0.0006). Conclusion: The significant relation towards traditional CV risk factors, IMT and manifest CV disease indicates that the proposed scoring system could be of value for assessing atherosclerotic-induced luminal narrowing. B-195 14:36 Detection of reperfused pulmonary arteriovenous malformations with contrast-enhanced magnetic resonance angiography G.K. Schneider1, A. Massmann1, M. Katoh1, U.W. Geisthoff2, A. Buecker1; 1 Homburg a.d. Saar/DE, 2Cologne/DE ([email protected]) Purpose: To evaluate contrast-enhanced magnetic resonance angiography (CE MRA) for detection of reperfused pulmonary arteriovenous malformations (PAVMs) after coil embolization in patients with hereditary hemorrhagic telangiectasia (HHT). Methods and Materials: Between February 1999 and March 2008, 256 patients with diagnosed HHT, or first degree relatives, underwent MRI screening for cerebral, pulmonary and visceral manifestations of HHT. Retrospective analysis was performed for patients with reperfused PAVMs after coil embolization. CE-MRA (gadobenate dimeglumine, 0.1 mmol/kg body weight) diagnosis of reperfused PAVM was confirmed by catheter angiography (CA). Results: A total of 128 PAVM in 48 patients were embolized using platinum coils. Complete occlusion of the feeding vessels was achieved in each case. Follow-up CE-MRA revealed reperfusion of 6/128 embolized PAVMs in 5/48 patients. Additionally, CE-MRA revealed six reperfused PAVMs in three patients who had undergone embolization elsewhere. All patients with reperfused PAVMs underwent CA and reembolization. No additional reperfused PAVMs were detected on CA. Reperfusion was due to biodegradation of coils caused by corrosion of tungsten filaments (two PAVMs in one patient), insufficient coil packing (eight PAVMs in five patients) and opening of collateral feeding vessels (two PAVMs in two patients). Conclusion: Reperfusion of PAVMs may occur over an extended time interval. Consequently, regular follow-up is mandatory. Our study shows that CE-MRA is a useful technique for follow-up of treated PAVMs. Unlike CT imaging, which may be compromised by metal artifacts arising from the embolization material, CE-MRA provides excellent image quality and is able to accurately detect PAVM reperfusion. Scientific Sessions B-196 14:45 Purpose: To intraindividually compare 0.1 mmol/kg doses of gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine (Gd-DTPA) for contrastenhanced MRA (CE-MRA) in patients with peripheral arterial occlusive disease (PAOD). Methods and Materials: Ninety-six patients underwent two CE-MRA examinations at 1.5 T using standard 3D spoiled GRE sequences. Contrast administration was randomized: 52 patients received Gd-BOPTA first; and 44 patients received Gd-DTPA first. Images were evaluated on-site for technical adequacy and vessel visualization quality and off-site (3 independent blinded readers) in matched-image pairs for vessel delineation, pathology detection/exclusion and diagnostic preference. Quantitative contrast enhancement (contrast-to-noise ratio [CNR]) of the pelvis, thigh and calf was assessed. Data were compared between groups using the Wilcoxon signed-rank test while interreader agreement was assessed using generalized + statistics. Results: Gd-BOPTA was associated with significantly fewer technically inadequate segments (20/564 [4%] vs. 67/564 [12%]; p 0.0001) and with significantly more segments of good or excellent quality (491/564 [87%] vs. 413/562 [73%]; p 0.0001). Off-site blinded readers 1, 2 and 3 preferred Gd-BOPTA overall in 75 (82%), 75 (82%) and 70 (76%) patients, respectively, compared with 4 (4%), 7 (8%) and 8 (9%) patients for Gd-DTPA (pb0.0001; all readers). Similar highly significant (pb0.0001) preference for Gd-BOPTA was expressed by each reader for all other qualitative endpoints in each territory. Three-reader agreement was good to excellent for each endpoint (+=0.46 [73% of patients] for diagnostic preference). Significantly (pb0.0001) higher CNR was noted for Gd-BOPTA in each territory. Conclusion: Gd-BOPTA at 0.1 mmol/kg bodyweight is significantly superior to equivalent-dose Gd-DTPA for CE-MRA of PAOD. B-197 14:54 Blood pool versus non-blood pool paramagnetic contrast agents in the MRA evaluation of peripheral arterial occlusive disease (PAOD) in comparison to digital subtraction angiography (DSA) M. Di Terlizzi, R. Ambrosini, R. Fossaceca, A. Carriero; Novara/IT ([email protected]) Purpose: To evaluate the diagnostic accuracy of high-resolution MRA sequences in the assessment of PAOD using a blood pool versus a conventional paramagnetic contrast agent, as compared to DSA. Methods and Materials: A total of 13 consecutive Type I diabetic patients with known PAOD (10 males, 3 females; mean age 62 years), scheduled for lower leg PTA, underwent MRA twice on a 1.5 T system using both an extracellular contrast agent (Gadobenate Dimeglumine, MultiHance, Bracco Diagnostic Inc, Italy) and an intravascular contrast agent (Gadofosveset Trisodium, Vasovist; Bayer Schering Pharma AG, Germany). 10 ml of Gadofosveset were injected at 1 ml/s; after the first-pass, a steady-state high-resolution acquisition was performed (voxel size = 0.5 x 0.5 x 0.5 mm, AT = 3 min). Within 2 weeks, the same patients underwent a second first pass MRA using 0.2 mmol/kg at 1 ml/s Gadobenate. All patients underwent DSA. Vascular tree was divided into 16 segments, with a total of 416 segments to be evaluated. Two experienced radiologists blindly evaluated the MRA datasets for significant vascular stenoses ( 50%) on a per-segment basis. Results: A total of 366/416 (87.9%) and 374/416 (89.9%) arterial segments were visualized during first-pass MRA using Gadofosveset and Gadobenate, respectively, with no statistically significant differences in detection and grading of stenoses. Steady-state Gadofosveset MRA allowed the correct evaluation of 408/416 segments (98%). Sensitivity, specificity and diagnostic accuracy were 85%, 84%, and 88% for first-pass MRA and 92.2%, 92.4%, and 97.5%, for steady-state Gadofosveset-MRA. Conclusion: Steady-state Gadofosveset-MRA appears as a robust imaging technique for the assessment of PAOD, with a diagnostic accuracy comparable to DSA. B-198 15:03 Asymptomatic deep vein thrombosis and incidental venous findings in 139 patients with peripheral artery disease referred for peripheral MRA with a blood pool contrast agent G.M. Kukuk, D.R. Hadizadeh, U. Fahlenkamp, A. Koscielny, F. Verrel, H.H. Schild, W.A. Willinek; Bonn/DE ([email protected]) Purpose: Prospective assessment of lower extremity veins as an adjunct to peripheral MRA with a blood pool contrast agent (BPCA) in patients with suspected or known peripheral artery disease (PAD). Methods and Materials: 139 patients with PAD were examined after single injection of the BPCA Gadofosveset Trisodium (Vasovist, Bayer Schering Healthcare, Germany) on a 1.5 T whole body MRI. First pass and steady state MRA was acquired for the evaluation of PAD with effective voxel sizes of 0.99 mmВі (upper legs) and 0.49 mmВі (lower legs). Steady state images were assessed by 2 radiologists in consensus in order to identify venous disease (deep vein thrombosis (DVT), varicosis, fistulae, etc). and to determine suitable veins for bypass graft surgery. Duplex ultrasound performed by an independent third reader served as the standard of reference. Results: In 49/139 (35%) MRA with BPCA revealed additional venous disease. Incidental DVT was found in 3/139 (2%) patients, varicosis was present in 42/139 (30%) and arterio-venous fistula was diagnosed in 1/139 (0.7%). 43 of 139 patients (31%) were scheduled for coronary bypass surgery (6/43) or peripheral bypass surgery (37/43). MRA with BPCA allowed for mapping of veins suitable for bypass surgery in all 43/43 patients eligible for bypass surgery. All imaging findings were confirmed by Duplex US and intraoperative results. Conclusion: Peripheral MRA with a BPCA allows for diagnosis of incidental, but relevant venous disease including asymptomatic DVT in patients with PAD and may become a promising clinical indication to determine concomitant arterial and venous disease. B-199 15:12 Steady state imaging with blood pool contrast agent MRA in patients with critical lower limb ischaemia for venous mapping bypass graft assessment: Initial experience G.H. Roditi, D. Orr; Glasgow/UK ([email protected]) Purpose: Assess potential of MRA with blood pool contrast agent compared to ultrasound for lower limb vein mapping in assessing conduit suitability. Methods and Materials: Ethics committee approved study with informed consent from patients with Fontaine stage III or IV lower limb ischaemia. MRA with blood pool contrast agent, hybrid dual injection technique with dynamic MRA at tibial station, then stepping table bolus chase MRA and subsequent high resolution steady state imaging of calves and thighs. Ultrasound assessment was with standard protocol and descriptive report. Image quality assessed on a scale. Deep veins evaluated for patency and evidence of thrombosis. Quality and calibre of the major superficial veins, sites of division & major tributaries were recorded. Superficial leg vein quality and diameter at reference points plus relevant variant anatomy were compared between modalities. MRI studies were compared to the descriptive duplex reports with a scale of utility. Results: 20 patients. MRI image quality excellent in all but one where imaging was corrupted by motion. All deep veins patient with no DVT. Vein diameters assessed up to 20% smaller calibre on MRA (accounted for by the differences in technique supine with cuffs deflated for MRI, erect with tourniquets to aid venous distension for ultrasound). MRA showed more superficial veins, more divisions and more large perforating tributaries than ultrasound. MRA was judged more informative than the descriptive ultrasound reports. Conclusion: Lower limb MRA with blood pool contrast agent and steady state imaging may obviate ultrasound in the assessment for vein bypass grafting. B-200 15:21 MR-lymphangiography at 3.0 T: Correlation with lymphoscintigraphy M. Notohamiprodjo, M. Weiss, R. Baumeister, T.F. Jakobs, C. Glaser, M.F. Reiser, K.A. Herrmann; Munich/DE ([email protected]) Purpose: To correlate the findings in contrast-enhanced MR-lymphangiography (MRL) with lymphoscintigraphy for detection and visualization of pathologies of the peripheral lymphatic system. Methods and Materials: A total of 20 consecutive patients with various pathologies of the peripheral lymphatic system, including uni- or bilateral lymphedema, lymphoceles and lymph-vessel-transplants were examined with a fat-saturated T1w3D-GRE-(FLASH)-sequence (TR3.76 ms/TE1.45 ms/FA30В°/voxel-size 0.83 mm3) after intracutaneous injection of Gd-DTPA on a 3.0 T-scanner (Magnetom VERIO). Four anatomic levels were examined from the foot to the pelvis. Two radiologists A B C D E F G H S183 Friday Multicenter, double-blind, randomized, intraindividual crossover comparison of gadobenate dimeglumine (MultiHanceВ®) and gadopentetate dimeglumine (MagnevistВ®) for MR angiography of the peripheral arteries T. Leiner1, T. Le Maire2, S. Miller3, S. Thurnher4, A. Vanzulli5, J. Vymazal6, M. Wasser7, M.A. Kirchin5, G. Pirovano8; 1Maastricht/NL, 2Eindhoven/NL, 3 TГјbingen/DE, 4Vienna/AT, 5Milan/IT, 6Prague/CZ, 7Leiden/NL, 8 Princeton, NJ/US Scientific Sessions and one nuclear-physician evaluated the depiction of lymph-collectors, pattern of drainage, number of visualized levels and lymph-nodes in consensus using a 3-point scale. Conventional lymphoscintigraphy with a colloid-bound 99Tcmtracer served as standard of reference. Statistical analysis was performed using intraclass-correlation. Results: All MRL were well tolerated and diagnostic. Correlation between MRL and lymphoscintigraphy was excellent (r=0.92). Normal and instant lymphatic drainage was observed in unaffected extremities with both modalities shortly after contrast application. Depiction of delayed drainage, lymph-transplants and lymphoceles was overall concordant in both modalities. Reduced lymphatic-drainage in lymphoscintigraphy correlated with lymph-vessel ectasia in MRL (9/20 cases). In 5/20 cases lymph-collectors were clearly visualized in MRL, whereas only hinted in lymphoscintigraphy. Depiction of inguinal lymph nodes was clearer in lymphoscintigraphy in 4/20 cases. In one case inhomogeneous fat-saturation obscured detection of diffuse drainage in MRL. Conclusion: MRL and lymphoscintigraphy correlation is excellent. Lymphoscintigraphy seems to better visualize inguinal lymph-nodes, whereas MRL is superior to depict lymph-collectors, anatomic details and morphological changes. MRL may become a valuable tool for planning and monitoring the microsurgical therapy. 14:00 - 15:30 Room K Computer Applications SS 305 New trends in PACS and workstations Moderators: R.C. Sigal; Buc/FR A. Simisker; Tartu/EE B-201 14:00 A solution to find lost chest radiographs in PACS server J. Morishita1, T. Hiwasa1, S. Katsuragawa2, Y. Sasaki3, Y. Sukenobu4, K. Doi5; 1 Fukuoka/JP, 2Kumamoto/JP, 3Morioka/JP, 4Suita/JP, 5Chicago, IL/US ([email protected]) Purpose: To develop an automated search method by use of biological fingerprints, i.e., some parts of chest radiographs, and image-matching technique in PACS server. The assumption of this study is based on that radiology personnel will find the occurrence of a missing current image in a specific patient folder before the image reading. Methods and Materials: We employed five biological fingerprints in a chest radiograph such as cardiac shadow, lung apex, the superior mediastinum, the right lower lung, and a thoracic field. Each of the biological fingerprints was used as a template for determination of the correlation value between the previous image of the lost current image and each of all current images in a database including 36,210 patients. All images were acquired in the lung cancer screening program. IRB approved and exempted from informed consent. Two hundred images were selected randomly, and used hypothetically as lost images to examine the potential usefulness of our method. Results: 78.5% (157/200) of the lost images were correctly identified as the same patient’s image from the large database. Moreover, it was possible to identify 89.0% (178/200) with 21 additional lost images correctly, when previous images with the top ten correlation index were examined. These results appear to be promising in finding a patient with the lost images based on comparison with a large number of images. Conclusion: Our method by use of biological fingerprints and image-matching technique would be a solution to find the lost chest radiographs automatically in the PACS server. B-202 14:09 Pseudonymization of DICOM data for clinical trials: A systematic review A. Valentinitsch, F. Kampl, P. Peloschek, F. Kainberger; Vienna/AT ([email protected]) Purpose: To analyze the suitability of currently existing systems for de-identification such as pseudonymization or anonymization of clinical data and the implementation in clinical trials. Methods and Materials: A manual and electronic search of Medline and technical databases was performed by using following keywords: de-identification, pseudonym, pseudonymization, anonymization, DICOM, clinical trials. Selected articles were published from 1998 to 2008. The evaluation criteria towards de-identification S184 A B C D E F G F H architecture were: type of de-identification (pseudonymization or anonymization), quantitative assessment of the encryption algorithm due to data security, development stage, DICOM data compatibility, PACS modularity, capability for clinical trials and patient confidentiality according to the EU Directive (95/46/EC). Results: Twenty-six articles fulfilled inclusion criteria: in 9 a pseudonymization process is described, and 17 describe an anonymization process (predominantly in form of k-anonymity). Only 3 studies describe possible model architectures of pseudonymization, which were developed for medical research networks, but may also be useful for clinical trials by considering the juridical aspects. Only one study was designed to propose in clinical a pseudonymization model of cancer registry that is in actual use in several German states. Unfortunately, only one study was published to propose a de-identification scheme based on pseudonymization that closely follows DICOM recommendation. Conclusion: Few studies demonstrated a pseudonymization process suitable for clinical trials. However, the studies about the reversible de-identification process embedded in a clinical trial were not conclusive, because clinical trials predominantly do not describe their de-identification methods due to patient confidentiality. B-203 14:18 Web-based multi-lingual structured reporting M. Fatehi1, A. Marashi2, A. Arjmand Shabestari1; 1Tehran/IR, 2Darmstadt/DE ([email protected]) Purpose: To introduce a web application, which provides multi-lingual structured reporting services. The reports can be prepared in the language of the user, but be printed in any other pre-defined language. Methods and Materials: The concept of multi-lingual structured reporting by point and click methods has been presented by the authors earlier, but this time a web application is developed to provide the tree-structure, which consists of “regions”, “blocks” and “items”. The interface is primarily designed in English language, but it can be customized to any other language. The templates are constantly revised to make them more applicable. Addition of a new language is possible through webmaster, but after definition the new language will be available for both “interface” and “output”. Results: Cardiac CT templates are now available for structured reporting in English and German languages. The website requires sign up and currently provides free reporting services to its users. The application relies on point and click methods, and “regions of interest” for reporting are provided through a collection of mapped images. The output report file can be printed or distributed as HTML file. Conclusion: Web-based approach to structured reporting enables users of the system to get the service from any location in the world and also get updated versions of SR platforms. In this way, since at the moment there is no international consensus on standard radiology language, web-based solution will help developers to update the list and content of their templates through time. B-204 14:27 Compression of digital images in radiology: Results of a German consensus conference R.W.R. Loose1, R. Braunschweig2, E. Kotter3, P. Mildenberger4, R. Simmler1, M. Wucherer1; 1Nuremberg/DE, 2Halle/DE, 3Freiburg/DE, 4Mainz/DE ([email protected]) Purpose: To find recommendations for “lossy” compression of digital radiological DICOM images in Germany by means of a consensus conference. The compression of digital radiological images was evaluated in many studies. Although the results demonstrate full diagnostic image quality of modality dependent compression between 1:5 and 1:200, there are only few clinical applications. Methods and Materials: A consensus conference with approx. 80 interested participants (radiology, industry, physics, and organizations) without individual invitation was organized by the working groups AGIT and APT of the German Roentgen Society DRG to determine compression factors without loss of diagnostic image quality for different anatomical regions of CT, CR/DR, MR, RF/XA examinations. The consent level was specified on at least 66%. Results: For individual modalities, the following compression factors were recommended: CT (brain) 1:5, CT (all other applications) 1:8, CR/DR (all applications except mammography) 1:10, CR/DR (mammography) 1:15, MR (all applications) 1:7, RF/XA (fluoroscopy, DSA, cardiac angio) 1:6. The recommended compression ratios are valid for JPEG and JPEG2000/Wavelet compressions. Conclusion: The results may be understood as recommendations and indicate upper limits of compression factors, where no reduction of diagnostic image quality has to be expected. The results of the German consensus conference are similar to actual national recommendations in Canada and England. Scientific Sessions B-205 14:36 Reconstruction of high-quality CTA from noisy cerebral CT perfusion data E.J. Smit1, A.M. Mendrik1, A. Waaijer1, G. Bertolini2, E.-J. Vonken1, B. van Ginneken1, M. Prokop1; 1Utrecht/NL, 2Padua/IT ([email protected]) B-206 14:45 Ultrasound (US) and magnetic resonance (MR): Is fusion imaging the way to the future of musculoskeletal imaging? E. Silvestri1, L.M. Sconfienza2, F. Lacelli3, S. Pucci1, F. Paparo1, G. Garlaschi1; 1 Genova/IT, 2San Donato Milanese/IT, 3Pietra Ligure/IT Purpose: US and MR are both valuable imaging techniques to study the musculoskeletal system. Nevertheless, each of them has several advantages and some disadvantages. Their fusion with a new imaging software could represent a new frontier in musculoskeletal radiology. The purpose of our paper is to present some features of this new technique applied to the study of the hand. Methods and Materials: 8 healthy volunteers underwent a MR scan of the hand (16 hands). T1-weighted sequences on axial, sagittal and coronal plans were acquired. Registration between volunteers’ anatomy and their MR data was done by clicking anatomic markers. Afterwards, these patients underwent a bilateral US scan of the hand. The US system consists of a scanner integrated with a system that provides the US image and its features such as the spatial dimension, orientation and probe field of view. These data are provided by the US scanner by the network connection and automatically updated at every change of position of the probe. Results: The system permitted a right representation in size and orientation of the MR images in real time during the US examination. There was a perfect correlation between US and MR images, with a relevant anatomic adherence. Information coming from MR scans was perfectly integrated with the US and readily available to the radiologist. Conclusion: Fusion imaging is a promising new technique in the study of musculoskeletal system in volunteers. However, further investigations are required to understand if this method is valuable in daily clinical practice. B-207 14:54 Multi-phase and multi-modality 3D visualization of CT and MR data sets J. Fornaro, B. Marincek, T. Frauenfelder; Zurich/CH ([email protected]) Purpose: With increasing spatial and temporal resolution of contrast-enhanced multi-detector computed tomography (MD-CT) and magnetic resonance (MR) imaging, acquisition of multiple well-timed data sets has become possible. Generally, these data sets are looked at individually or side by side. Often, it would be beneficial to review two or more data sets simultaneously by superimposing them, e.g. to relate pathology better appreciated in one data set to normal anatomy better appreciated in another data set. Methods and Materials: We implemented a two-step workflow for multi-volume visualization in a tool running on a standard commercially available Windows computer: (1) The data sets were automatically registered using a mutual informationbased algorithm to compute the correct spatial alignment of the data sets, followed by resampling to a common grid. (2) Concurrent direct multi-volume rendering of the aligned data sets, where the user can adjust the color and opacity transfer functions for the different data sets separately in real time. B-208 15:03 Thin client technology for offsite expert reading of runoff CTA in a vascular center B.C. Meyer1, K.J. Wolf1, F.K. Wacker2; 1Berlin/DE, 2Baltimore, MD/US ([email protected]) Purpose: To evaluate the benefits of thin client technology (TCT) for CTA reading in an on-call situation. Methods and Materials: A total of 20 CTA run-off data sets were read off-site in an on-call situation using a thin client solution (VisageCSВ® ThinClient,Visageimaging) and a digital subscriber line (6 Mbit/s). To assess the feasibility of using TCT by the interventional radiologist on call at home, time from the initial phone call to study availability on the client, and to final diagnosis were measured and compared to the processing time in the hospital (1Gbit,LAN). Results: DSL-based data transfer yielded an interactive experience with images in diagnostic quality available within less than 1 minute. Time from the initial phone call to study on screen ranged from 2:30 to 11 (median 6) minutes. The post processing time ranged from 5:30 to16:00 (median 12:30)minutes. The time from the initial phone call to the final diagnosis given to the resident ranged from 12:30 to21 (median 15) minutes. There was no significant time difference for post processing off-site and in the hospital (t-test, P 0.05). Off-site and on-site reading showed 100% agreement with regard to the therapeutic measures that were taken. Conclusion: For vascular emergencies, CT angiography (CTA) has replaced intra-arterial DSA in most cases. CTA data sets may comprise more than 3,000 images. In an on-call situation, however, data transfer and computing power can be bottlenecks. With the thin client solution presented, heavy processing is done at the server, and only the resulting screen content is transferred for reading. Therefore, sophisticated post-processing can be performed on a basic laptop or desktop computer. B-209 15:12 Image interpretation with emerging handheld devices: A comparative study of display performance P. Mc Laughlin, C. Brennan, J. Coyle, K. O’Regan, S. Mc Williams, A. Mc Garrigle, M. Maher; Cork/IE ([email protected]) Purpose: The potential role of handheld devices in the analysis of radiographic images has been identified in the scientific literature. Image interpretation with these handheld devices requires adequate display performance including sufficient detail resolution and low contrast detectability.We aim to objectively compare the display characteristics of a representative subset of handheld devices. Methods and Materials: Using the Artinis contrast detail phantom type 2.0, 4 observers objectively scored the display performance of the Iphone (Apple), N73 cellphone (Nokia) and the Ipaq PDA (Hewlett Packard). Threshold contrast as a function of object diameter was determined and the display performance of each device was plotted on a contrast detail curve. As a reference, the display performance of a 0.8 and 3-Megapixel monochrome liquid crystal display was also scored. CT images containing pulmonary nodules of size range 2-16 mm were viewed and subjective reader confidence in nodule identification was recorded using the visual analogue scale. Results: Nodules greater than 7 mm were identified with 100% confidence in all tested devices. Confidence for 7 mm nodule identification was greater for the Iphone than other tested devices. Contrast detail curves varied widely among the tested group. No significant interobserver variability existed p 0.001. The Iphone had superior contrast detectability and detail resolution than other handhelds and was comparable to that of the tested 0.8- Megapixel LCD Monitor. Conclusion: We conclude that recent advances in technology have improved the display performance of handheld devices such that their diagnostic efficacy may soon approach that of 0.8 Megapixel LCD monitors. A B C D E F G H S185 Friday Purpose: Current techniques for reconstructing CT angiography (CTA) from CT perfusion (CTP) data use single arterial phase (aCTP) or the temporal MIP (tMIP) but such images suffer from the increased image noise in thin-section CTP data. We developed and tested a technique that allows for reconstruction of high-quality CTA from noisy cerebral CTP data. Methods and Materials: We developed a novel method for reconstructing CTA from CTP data that combines the advantages of tMIP (high vascular contrast) and temporal mean (low image noise). This perfusion-derived CTA (pCTA) was tested on 17 patients with suspected subarachnoid haemorrhage who underwent CTP (80 kV, 150 mAs, 30 scans every 2s) and standard CTA with 64x0.625 mm collimation. Standard CTA, aCTP, tMIP and pCTA were randomized and blindly presented to an expert who was unaware of the techniques. All scans were scored on a 5-point scale for arterial contrast, detail visibility, vascular noise and overall image quality. Image noise was determined over a 100 mm2 homogenous ROI. Results: pCTA yielded significantly superior visual scores for overall image quality and vascular noise (p 0.05). Overall image quality with tMIP was significantly superior to both CTA and aCTP. Detail visibility was similar to tMIP but significantly better than CTA and aCTA. Arterial contrast was significantly higher than for standard CTA and similar to tMIP and aCTA. Image noise was significantly lowest on pCTA and highest for aCTA. Conclusion: Our CTA reconstruction algorithm appears superior to conventional CTA of the brain and existing techniques for reconstructing CTA from CTP data. Results: In a preliminary retrospective study, we successfully applied the described technique to 10 clinical multi-phase MD-CT and MR data sets of the upper abdomen. The automatic registration of image data sets was reliable and time efficient (mean time 5.5 seconds). User interaction for multi-volume rendering was similar to single-volume rendering. Multi-volume rendering enabled concurrent and clearly distinguishable visualization of upper abdominal pathology and anatomy of interest in a single 3D image, without the need for tedious segmentation. Conclusion: Multi-phase and multi-modality 3D visualization enhances the understanding of volumetric medical data. Scientific Sessions B-210 B-212 15:21 An autostereoscopic 3D display improves identification of intracranial arteries in 3D models from time-of-flight MR-angiography A. Abildgaard, A.K. Witwit, J.S. Karlsen, E.A. Jacobsen, B. TennГёe, G. Ringstad, P. Due-TГёnnessen; Oslo/NO ([email protected]) Purpose: To evaluate whether the visual interpretation of 3D models from intracranial time-of-flight (TOF) MR-angiography (MRA) is improved by a new autostereoscopic 3D display. Methods and Materials: Maximum intensity projection (MIP) and volume rendering (VR) greyscale 3D models of intracranial arteries were created from ten anonymised TOF MRA data sets. The models were displayed on a novel 20 inch autostereoscopic 3D display, which provides a true 3D perception without requiring specialized viewing glasses. A predefined selection of 31 clinically relevant arteries or arterial segments were digitally marked in the TOF source images. Each marking was displayed in a separate 3D model as an overlying red dot. Three neuroradiologists viewed the models in a randomized sequence, aiming to correctly identify the marked artery in each model. A paired comparison was performed between arterial identifications with the display operating either in 3D mode or in 2D mode. Results: For all readers combined, 651 paired comparisons were done (314 MIP and 337 VR). With MIP, 233 arterial markings (74 %) were identified correctly in 3D mode versus 179 (57%) in 2D mode. The odds ratio for correct identification with 3D mode versus 2D mode was 2.17 (95% confidence interval 1.55-3.04, P 0.001). With VR, 256 markings (75 %) were correctly identified using 3D mode and 229 (68 %) using 2D (Odds ratio 1.49, 95% confidence interval 1.06-2.09, P = 0.021). Conclusion: Identification of intracranial arteries in 3D models from TOF MRA can be improved by use of an autostereoscopic 3D display. 14:00 - 15:30 Room L/M Neuro SS 311 Functional magnetic resonance imaging Moderators: K. Aydin; Istanbul/TR S. Sunaert; Leuven/BE B-211 14:00 Compensatory brain activity of selective attention in patients with postconcussion syndrome one month after minor head injury M. Smits1, D.W.J. Dippel1, G.C. Houston2, P.A. Wielopolski1, P.J. Koudstaal1, M.G.M. Hunink1, A. van der Lugt1; 1Rotterdam/NL, 2's Hertogenbosch/NL ([email protected]) Purpose: After minor head injury (MHI), postconcussive symptoms (PCS) such as attention deficits frequently occur. It has been hypothesised that PCS are caused by microstructural damage to the brain, causing a functional deficit. The purpose of this study was to correlate functional MRI brain activation of selective attention with PCS. Methods and Materials: 21 patients 1 month after MHI and 12 healthy controls (matched for age, gender and educational level) were scanned at 3 T. For functional imaging, a T2*w GE-EPI sequence was used (TR/TE 2000/30 ms; acquisition time 6:10 minutes), during which a Counting Stroop task was presented visually to engage selective attention. Random effects group analyses were performed using SPM2 (Wellcome department, London, UK), correlating brain activation with the severity of PCS as evaluated with the Rivermead Postconcussion Symptoms Questionnaire (RPSQ). Results: Mean age was 28 years (range, 18-45 years), 20 were male. Median RPSQ score was 8 (range, 0-46). In all subjects combined, significant (pcorrected 0.05) activation was seen in the dorsolateral and ventrolateral prefrontal cortex, the supplementary motor area, and in the inferior and superior parietal lobule and precuneus (posterior parietal area). Increased activation (puncorrected 0.001), associated with greater severity of PCS, was seen in the ventrolateral prefrontal cortex, anterior and posterior cingulate cortex and precuneus (posterior parietal area). Conclusion: Patients with PCS 1 month after MHI show increased activation during performance of a selective attention task. Such increased brain activity may be considered a reflection of the brain’s compensatory response to - microstructural - injury in patients with PCS. S186 A B C D E F G F H 14:09 fMRI monitoring of mirror visual feedback therapy in phantom limb pain G. Kasprian, S. Seidel, J. Furtner, M. Weber, T. Sycha, E. Auff, D. Prayer; Vienna/AT ([email protected]) Purpose: This fMRI study aims to assess the cortical activation patterns pre- and post-neuromodulatory mirror visual feedback therapy (MVFT) in lower limb amputees with phantom limb pain (PLP). Methods and Materials: Nine patients (mean age 50.8 years) with traumatic (n = 8) or ischemic (n = 1) etiology of lower limb amputation (level of right thigh-3, left thigh-3, left calf-2, left hip-1) and 2 healthy controls underwent fMRI at 1.5 Tesla using a BOLD sensitive T2*-weighted multislice gradient echo EPI sequence covering the whole brain (TE = 50 ms, TR = 3616 ms, matrix = 96 x 78, 100 dynamics, acquisition time 6 min). Activation (rhythmic flexion and extension of the existing and/or phantom foot) was measured against rest, pre- and post-12 sessions of MVFT. Results: Identical (n = 6), reduced (n = 4), and caudally shifted (n = 1) motor representation of the missing lower extremity was found in the corresponding M1 area and ipsilateral supplementary motor area (SMA) activation was increased (n = 5) compared to the motor/SMA representation of the intact contralateral leg. In controls and patients (n = 8), primary motor activation patterns remained unchanged after MVFT. One out of three clinical responders showed signs of cortical reorganization after therapy. Conclusion: This is the first study to document the neurophysiologic basis of MVFT in lower limb amputees and the utility of fMRI as clinical monitoring tool of therapy response in drug resistant PLP. B-213 14:18 Postoperative language deficits with resection of the supplemental motor area: Correlation with preoperative functional MR imaging J. Lyo, N. Petrovich, K.K. Peck, A.I. Holodny; New York, NY/US ([email protected]) Purpose: The supplemental motor area (SMA) is involved in higher order language processing. Does pre-operative determination of SMA laterality with fMRI predict postoperative speech deficits? Methods and Materials: fMRI was performed on fifteen patients with lesions involving the SMA (sparing Broca and Wernicke areas) prior to resection. fMRI language paradigms were performed (verb generation, category generation, and phonemic fluency), along with formal neuropsychologic testing before and after surgery. fMRI was performed on 1.5 T or 3 T GE scanners using echo-planar imaging. SMA functional activity was quantified with AFNI using volumetric ROI on bilateral SMA, with cross-correlation analysis p-value 0.001. Laterality index for SMA activation = (Left - Right)/(Left + Right). Results: Six of the fifteen patients with partial or complete resection of the SMA developed speech deficits, from expressive language impairment to mutism and global aphasia, and these patients had left lateralized SMA with ipsilateral resection. All six demonstrated significant recovery of speech within 6 weeks. Two patients had pre-existing language deficits, not significantly altered with surgery: one had right lateralized SMA and contralateral resection; the other, left lateralized SMA and ipsilateral resection. All patients with resection of the non-lateralized SMA did not develop a language deficit (SMA was lateralized to the right in three, and left in four of these patients). Conclusion: Tumor resection of all or part of the fMRI-lateralized SMA resulted in language deficits. Resection contralateral to the fMRI-lateralized SMA resulted in no speech deficits. B-214 14:27 Evaluation of language processing in fMRI at 7 T N. Koschnicke, S. Maderwald, J.M. Theysohn, K. GroГџkurth, M.E. Ladd, E.R. Gizewski; Essen/DE ([email protected]) Purpose: fMRI is one of the most likely applications to benefit from high-field MRI. It profits from the higher signal-to-noise ratio (SNR) and increased BOLD contrast itself. To our knowledge, no one has yet evaluated this advantage at 7 T with a focus on speech regions. Methods and Materials: Ten right-handed volunteers were measured at both 1.5 and 7 T solving tasks (word generation and synonym detection test) with fMRI in a block design fashion. An EPI sequence with short TE (28 ms at 7 T) and parallel imaging (GRAPPA R = 3) was chosen. An 8-channel transmit/receive head coil (Rapid Biomed, Germany) was used for image acquisition at 7 T. Statistical analyses were performed using SPM 05. Results: Cerebral areas involved in language processing, speech production, and comprehension (Broca’s and Wernicke’s area) could be revealed using 7 T. One volunteer revealed activation in both hemispheres which was not detected at 1.5 Scientific Sessions B-215 14:36 Real-time fMRI biofeedback may improve chronic tinnitus: Proof of principle S. Haller1, R. Veit2; 1Basle/CH, 2TГјbingen/DE ([email protected]) Purpose: Tinnitus is accompanied by excess auditory activations. Transient reduction of this activation via transcranial magnetic stimulation (TMS) may reduce tinnitus. We tested the hypothesis that participants with chronic tinnitus can learn to voluntarily reduce the auditory activation by means of real-time fMRI biofeedback. Methods and Materials: Four participants with chronic tinnitus were included (preliminary results). First, the individual auditory cortex was determined in standard fMRI auditory block-design. Then, participants trained to voluntarily reduce the auditory activation using real-time fMRI with visual biofeedback of the current auditory activation. Tinnitus self-assessment was done before and after biofeedback training. Results: Most participants successfully learned to voluntarily reduce auditory activation, which reduced the subjective tinnitus sensation in the majority of subjects. Conclusion: These preliminary results prove the concept that voluntary reduction of auditory activations by real-time biofeedback fMRI may reduce tinnitus. Optimized training protocols might further improve the results. B-216 14:45 The effect of glaucoma on the posterior visual pathway: A combined fMRI and DTI study Q. Zhang, Y.-T. Zhang, J. Zhang, W. Li; Tianjin/CN ([email protected]) Purpose:To explore the abnormal changes of the visual cortex and bilateral optic radiation in patients with glaucoma with fMRI and DTI. Methods and Materials: A total of 16 patients with chronic angle-closure glaucoma and without any diseases in the posterior visual pathway were recruited in this study. Sixteen matched subjects were selected as control. Informed consent was obtained from all patients and subjects. Block-designed fMRI was performed with a 1.5 T MR scanner (TR/TE 2000/60 ms; Matrix 64 x 64; thickness 5 mm; slice gap 1 mm). Black and white check board and “+” were used as stimulus and control, respectively; six control and five stimulus blocks ran alternately and every block lasted for 20 s. Bilateral eyes in the two groups received stimulus individually. The fMRI data were processed with SPM2. Different mappings between the two groups were obtained with inter-group analysis. DTI was performed with 13 diffusion directions and B value of 1,000 s/mm2. FA values of bilateral optic radiation between the two groups were evaluated with two-sample t-test. Results:In the subjects, activated regions mainly included the primary visual cortex and cuneus, lingual gyrus, middle gyrus of the occipital lobe, fusiform gyrus and the inferior temporal gyrus. The activated extent and intensity of the visual cortex decreased in patients when compared with the subjects, especially in the advanced stage of glaucoma. The FA values in the bilateral optic radiation were obviously decreased in the glaucoma than in the subjects. Conclusion:The posterior visual pathway may be damaged by glaucoma, especially in the advanced stage, and those damages of the posterior visual pathway can be detected with fMRI and DTI. B-217 14:54 Background MR gradient noise and non-auditory BOLD activations: A data-driven perspective S. Haller1, G. Homola2, C.F. Beckmann3, J. Bartsch2; 1Basle/CH, 2WГјrzburg/DE, 3 London/UK ([email protected]) Purpose: The effect of echoplanar imaging (EPI) of acoustic background noise on blood oxygenation level-dependent (BOLD) activations was investigated. Two EPI pulse sequences were compared: (i) conventional EPI with a pulsating sound component of typically 8-10 Hz, which is a potent physiological stimulus and (ii) recently established continuous-sound EPI, which is perceived as less distractive despite equivalent sound pressure level. Methods and Materials: A total of 16 healthy subjects performed an established demanding visual n-back working memory task. Using an exploratory data analysis technique (tensorial probabilistic independent component analysis; tensor-PICA), we studied the inter-session/within-subject response variation introduced by continuous-sound versus conventional EPI acoustic background noise in addition to temporal and spatial signal characteristics. Results: The analysis revealed a task-related component associated with the established higher-level working memory and motor feedback response network, which exhibited a significant 19% increase in its average effect size for the continuoussound as opposed to conventional EPI. Stimulus-related lower-level activations, such as primary visual areas, were not modified. Conclusion: EPI acoustic background noise influences much more than the auditory system per se. This analysis provides additional evidence for an enhancement of task-related, extra-auditory BOLD activations by continuous-sound EPI due to less distractive acoustic background gradient noise. B-218 15:03 Potential impact of 32 channel receiver coil technology on functional magnetic resonance imaging J. Linn1, M. Burke2, K. Haegler1, V. SchГ¶pf1, A.-M. Kleemann1, M. Wiesmann3, J. Albrecht1; 1Munich/DE, 2Solingen/DE, 3Schwerin/DE ([email protected]) Purpose: Using finger tapping as the standard motor task for functional magnetic resonance imaging (fMRI), we aimed to test the potential of a 32 channel coil for performing fMRI compared to a standard 8 channel coil. Methods and Materials: Brain activations were investigated in 14 healthy righthanded subjects performing finger tapping with the right index finger during two experimental sessions, one with the 8 channel coil and one with the 32 channel coil. The order of both sessions was pseudorandomized. The experiment was carried out based on a conventional block design and functional imaging data were analyzed using SPM5. Additionally signal to noise and contrast to noise ratios were compared. Results: During both sessions activation on an FWE-corrected level was observed in the motor cortex (precentral gyrus). A paired t-test comparing the effects of finger tapping with the contrast “8 channel coil 32 channel coil" revealed no activations, whereas the contrast "32 channel coil 8 channel coil" revealed activations in the left hippocampus, left middle temporal gyrus, left middle and superior frontal gyrus, left and right cerebellum, left and right temporal pole, left fusiform gyrus, and left precentral gyrus (p 0.001 uncorrected for whole brain volume). Conclusion: We demonstrated that the 32 channel coil indicated higher contrast to noise ratios, and thus a more significant brain activation compared to the 8 channel coil. This technology has a potential impact on fMRI as well as on studies employing dynamic signal changes e.g. contrast enhanced angiography or perfusion studies. B-219 15:12 High-resolution functional MRI image using phase information T. Yoneda, Y. Hiai, H. Arimura, Y. Kitajima, S. Tomiguchi, T. Hirai, Y. Yamashita; Kumamoto/JP ([email protected]) Purpose: The signal of phase image is quite sensitive to the subtle change in blood oxygen level. We develop a new technique to create fMRI image using phase information and examine a possibility of creating high-resolution fMRI image with short scan time. Methods and Materials: Hand grasping as activation is carried out for each of the seven healthy volunteers. Each volunteer is scanned for three sets of activation and rest state using PRESTO sequence (TR/TE = 31/50 ms, FA = 10 deg., FOV = 230 mm). We accumulate these data as dicom phase and magnitude files. Phase difference-enhanced imaging (PADRE) technique, which enhances small values of phase differences, calculates these data to create functional signal by subtracting between the functional signal data of rest and activated states with the appropriate threshold. Statistical test of signal appearance is carried out by setting ROI on the activated area, which is defined by conventional fMRI image and inactivated area symmetrically located about the central gyrus. Results: We create a functional image whose matrix size is 256 x 256. Paired ttest shows clearly the difference between the activated area and inactivated area (P 0.01) with appropriate threshold to create functional images. Additionally, we can eliminate signal on the vessel by changing the filter size, which had been already equipped to PADRE, to reduce false-positive signal due to the in-flow effect on fMRI image. Conclusion: High-resolution fMRI image is created using phase information. We confirm that functional image using phase information shows activated signal precisely from the statistical point of view. A B C D E F G H S187 Friday T. The same corrected p value (p = 0.001) was used for all analyses. Furthermore, the BOLD signal change was significantly higher at 7 T than at 1.5 T (factor 2 to 3), while at the same time acquiring a voxel level at 7 T that was 5 to 6 times higher compared to 1.5 T. A well-fitted response curve could be detected in all speech areas at 7 T. Conclusion: We detected speech areas consistently and reliably using whole-brain fMRI at 7 T with good-quality response functions and, as expected, higher signal compared to 1.5 T, even though using higher spatial resolution. Scientific Sessions B-220 15:21 Functional area reorganization in experimental spinal cord injury: Functional magnetic resonance imaging study N. Chen, K. LI, X. Wang; Beijing/CN ([email protected]) Purpose: To study the characteristic of functional area plasticity after the spinal cord injury in rat. Methods and Materials: Ten SD rats of completed spinal cord injury (SCI) at T6 level were performed the fMRI studies which with the electrical stimulation of the left forepaw based on a block design at 4 weeks and 8 weeks after injured, and ten normal rats as control groups. The MR images were spatially normalized to the Paxinos and Watson atlas. Quantitative cluster analysis was carried out to calculate the volumes and centers of activation in brain structures. Results: The activation was confined to the contralateral somatosensory cortex (CSC) in normal animal and extensive activation such as ipsilateral thalamus and the caudate putamen was found in injured groups. The average center of activation of the CSC was significantly different between the normal and injured animals (P 0.01). The average percentages of activation at CSC were no statistically significant between them. The global volumes of activation in the normal, 4 and 8 week injured rats were 23p5, 59p13, and 61p21 mm3, respectively, and there was significant difference (P 0.01) between the normal and injured animals. The center of activation and activation volume for the ipsilateral caudate putamen and the thalamus was statistically different (P 0.01) between the 4 and 8 week post injury. Conclusion: These studies suggest extensive and ongoing plasticity in SCI-injured animals. The quantitative information could be important in objectively monitoring the effects of various therapeutic interventions and rehabilitation program in SCI. 14:00 - 15:30 Room N/O Preclinical applications Moderators: C. Pirich; Salzburg/AT E.A. Schellenberger; Berlin/DE 14:00 Dynamic MRI assays of endothelial permeability for the differentiation of tumors with high from tumors with low VEGF-activity C.C. Cyran1, B. Sennino2, Y. Fu2, B. Chaopathomkul2, D.M. Shames2, M.F. Wendland2, D.M. McDonald2, R.C. Brasch2; 1Munich/DE, 2San Francisco, CA/US ([email protected]) Purpose: To evaluate dynamic MRI assays of endothelial permeability for their potential to differentiate tumors with high intrinsic vascular endothelial growth factor (VEGF) activity from tumors with low VEGF-activity by correlating MRI assays of endothelial permeability with immunohistochemical measurements of VEGF on a tumor-by-tumor basis. Methods and Materials: Subcutaneous tumor xenografts were grown in athymic rats (n=13) from two poorly differentiated, estrogen-receptor-negative human breast cancer cell lines; MDA-MB-231 (n=5) with a high level of intrinsic VEGF-activity and MDA-MB-435 (n=8) with a low level of intrinsic VEGF-activity. Dynamic contrastenhanced MRI was performed at 2.0T using the macromolecular contrast agent albumin-(Gd-DTPA)27. Quantitative estimates of tumor microvessel permeability (KPS; Вµl/minВ·100 cm3), based on a two-compartment kinetic model, were correlated with area-density (%) measurements of VEGF-immunoreactivity on tumor sections. Results: Tumor endothelial permeability, assayed as the endothelial transfer coefficient KPS, was significantly higher (p 0.03) in MDA-MB-231 tumors (KPS=58p30.9 Вµl/ minВ·100 cm3) than in MDA-MB-435 tumors (KPS=24p8.4 Вµl/minВ·100 cm3, p 0.05). Correspondingly, VEGF area-density in MDA-MB-231 tumors was significantly higher (27.3p2.2%) than in MDA-MB-435 human breast cancer xenografts (10.5p0.5%, p 0.05). Individual measurements for the two groups did not overlap. The correlation between KPS values and measurements of VEGF area-density was significant (r=0.68, p 0.01). Conclusion: Dynamic MRI assays of endothelial permeability have the potential to non-invasively assess VEGF-activity in tumors and could be clinically applicable to define the suitability of patients for VEGF-inhibiting anti-angiogenic drug therapy. A B C Purpose: New relaxometry methods have recently been successfully applied to monitor anti-vascular therapies in vivo. Classical anti-angiogenic treatment protocols clearly differ from anti-vascular therapies with respect to the biological response of the tumor tissue. The purpose of this study was therefore to evaluate a $R2* multiecho MR-Relaxometry sequence for early assessment of anti-angiogenic tumor treatment effectiveness using the VEGF inhibitor bevacizumab (AvastinВ®). Methods and Materials: A673 bearing nude mice were injected with bevacizumab (n = 6) or saline as control, respectively (n = 6). MR imaging was performed before and after 2 cycles (100 Вµg bevacizumab on day 0 and 3) of therapy (day 7). USPIOinduced changes (SHU 555 C) of $R2* were measured in regions of interest. The VVF, as a known surrogate marker of the microvessel density (MVD), was calculated. The MVD was determined by immunohistochemistry and correlated with MRI results. For statistical analysis an unpaired t-test was applied. Results: Bevacizumab treatment resulted in a significant reduction of $R2* values compared to the controls (bevacizumab: 10.47 p 0.78 s-1 vs. control: 17.91 p 2.63 s-1, p 0.01) accompanied by a significant decrease of the VVF by 33% (bevacizumab: 2.21 p 0.15% vs. control: 3.31 p 0.22%; p 0.01). The MVD confirmed the MR results showing a 25% reduction after treatment (bevacizumab: 7.11 p 0.3 vs. control: 9.45 p 0.38; p 0.05). Conclusion: USPIO enhanced Multi-echo $R2* MR-Relaxometry allows an accurate and early assessment of anti-angiogenic tumor treatment and may thus be exploited for clinical therapy monitoring. D E 14:18 Effect of antiangiogenic therapy to the luciferase activity controlled by a HSP70 and CMV promoter in combination with MRI imaging in a M21 tumor model W. Hundt1, C.E. O’Connell-Rodwell2, D. Mayer2, S. Guccione2; 1Marburg/DE, 2 Stanford, CA/US ([email protected]) SS 306 S188 14:09 Multi-echo delta R2* MR-relaxometry for antiangiogenic tumor treatment monitoring J. Ring1, T. Persigehl1, S. Remmele2, W. Heindel1, H. Dahnke1, C. Bremer1; 1 MГјnster/DE, 2Hamburg/DE ([email protected]) B-223 Molecular Imaging B-221 B-222 F G F H Purpose: We investigated the effect of targeted gene therapy to the M21 tumor cell line combining bioluminescence (BLI) and MRI imaging. Methods and Materials: M21 transfected with a plasmid containing the hsp70 or the CMV promoter fragment and the luciferase reporter gene were grown to a size of 900 mm3. Five animals in each group were intravenously treated with a AvB3-NP/ RAF (-) complex every 72 hours. Bioluminescence and MRI were performed at set time intervals. The MRI scan protocol was T1-wt-SEpCM, T2-wt-FSE, Diffusion-wtSTEAM-sequence, T2-time obtained on a 1.5-T-GE-MRI scanner. Results: The size of the treated M21 tumors kept nearly constant during the treatment phase (837.8p133.4 versus 914.8p134.4 mm3). BLI showed that the luciferase activity controlled by the CMV promoter decreased to 51.1p8.3%. Controlled by the hsp70 promoter, the highest luciferase activity (4.4p0.3 fold) was seen after 24 hours. The SNR value (T2-weighted images) of the tumors was 36.7p0.6 and dropped down to 31.2p4.4 (p=0.004). At the beginning, the SNR value (T1-weighted images) of the tumors after contrast medium application was 42.3p1.9 and dropped down to 28.5p3.0 (p 0.001). In the treatment group, the diffusion coefficient increased significantly under therapy (0.54p0.009 versus 0.66p0.05). Conclusion: Targeted antiangiogenic therapy can induce luciferase activity under the control of an hsp70 promoter. MRI showed a significant reduction of contrast medium uptake and increase of the diffusion coefficient of the tumors. B-224 14:27 Imaging of early vascular response to heavy ion irradiation by targeted ultrasound M. Palmowski1, J. Huppert2, P. Peschke2, P. Hauff3, M. Reinhardt3, M. MГ¤urer4, W. Semmler2, F. Kiessling1; 1Aachen/DE, 2Heidelberg/DE, 3Berlin/DE, 4Erlangen/DE ([email protected]) Purpose: Individualization of therapy regimen combining radiotherapy with antiangiogenic drugs demands for non invasive insights into the regulation of angiogenic markers. While angiogenic marker expression after conventional radiotherapy has been studied, little is known about their response to heavy ion therapy (HIT). Thus, we investigated if molecular ultrasound can be used to intraindividually track changes in the angiogenic marker expression after HIT. Methods and Materials: Expression of ICAM-1 and of AvB3-Integrin in subcutaneous AT-1 prostate cancers in rats treated with HIT was studied by molecular ultrasound and by immunohistochemistry. For this purpose, cyanoacrylate microbubbles were Scientific Sessions B-225 14:36 MR imaging of lipoprotein metabolism with lipophilic USPIO at 3 T H. Ittrich, O. Bruns, K. Peldschus, M. Kaul, U. Tromsdorf, R. Reimer, A. Koops, U. Beisiegel, G. Adam; Hamburg/DE ([email protected]) Purpose: To develop dynamic MRI methods for in vivo imaging of liver lipoprotein uptake and disorders in metabolism via MRI. Methods and Materials: New nanosomes were designed in vitro with a magnetic iron oxide core (USPIO) coated by a lipid-lipoprotein layer. In vivo dynamic MRI using a T2*w FFE was performed before, during, and after i.v. application of USPIO in apolipoprotein E (ApoE) deficient and wildtype mice (WT, control) using a clinical 3 T scanner with a small animal solenoid coil. R2* measurements were performed before (ba) and after (pa) USPIO application using a fat-saturated multi-echo FFE. SNR in vena cava, aorta, portal vein, and liver as well as R2* of the liver were measured. Uptake kinetics and R2* in were tested for statistical significance (t-test, p 0.05) and matched with histology (H&E, Prussian blue) and electron microscopy. Results: In vivo measurements showed a two-phase exponential SNR decrease after UPSIO application in order of vena cava, aorta, portal vein, and liver followed as well as a stable SNR drop in the liver of WT (ba: 43.9 p 2.3, pa: 8.2 p 1.2). ApoE deficient animals showed a significantly delayed and reduced SNR decline of the liver (ba: 44.2 p 3.1, pa: 10.6 p 0.6; p 0.03). Correlating the R2* of WT showed a significantly higher increase (ba: 76.3 p 3.4 sec-1, pa: 164.3 p 11.4 sec-1) compared to ApoE mice (ba: 79.9 p 2.5 sec-1; pa: 114.7 p 5.1 sec-1, p 0.004). Corresponding to MR imaging histology and electron microscopy showed a predominantly accumulation of nanosomes in hepatocytes, but not in Kupffer cells. Conclusion: Liver uptake of USPIO-marked lipoproteins and defects in liver lipoprotein metabolism can be monitored and detected by real time MRI at a clinical 3 T MR system. B-226 14:45 In vivo molecular imaging of thrombus formation R.-J.J.H.M. Miserus, L. Prinzen, V.M. Herias, T.M. Hackeng, M.A.M.J. van Zandvoort, M.J.A.P. Daemen, J.M.A. van Engelshoven, S. Heeneman, M. Kooi; Maastricht/NL ([email protected]) Purpose: Thrombus formation plays a central role in several cardiovascular diseases. During the early stages of thrombus formation, activated factor XIII cross-links A2-antiplasmin to the fibrin network, increasing the resistance of thrombi against thrombolysis. Therefore, early detection of thrombus formation is vital. Methods and Materials: A bimodal contrast agent (CA) was synthesized by coupling gadolinium-DTPA and rhodamine to an A2-antiplasmin-based peptide. For the control CA, a glutamine residue essential for cross-linking was replaced by alanine. In vitro-generated thrombi were exposed to both CAs and imaged by MRI (1.5 T) and two photon laser scanning microscopy (TPLSM). In vivo feasibility of the CA in detecting early thrombus formation, specifically, was investigated in a mouse model with MRI (7T using an inversion recovery turbo spin echo pulse sequence). Results: In vitro-generated thrombi exposed to the A2-antiplasmin-based CA showed hyperintense MR signal intensities at the thrombus edge. No hyperintense signal was observed using the A2-antiplasmin-based CA in the presence of FXIII inhibitor dansylcadaverine, nor when using the control CA. TPLSM demonstrated that the A2-antiplasmin-based CA was bound to fibrin. In vivo CA administration within seconds after inducing thrombus formation increased contrast-to-noise ratios (CNR: 2.28 p 0.39, N = 6) at the site of thrombus formation compared to the control CA (CNR: -0.14 p 0.55, P = 0.003, N = 6) and A2-antiplasmin-based CA administration 24-48 hours after thrombus formation (CNR: 0.11 p 0.23, P = 0.006, N = 6). Conclusion: A novel bimodal CA was developed, characterized and validated. Our results showed that this bimodal CA enabled non-invasive in vivo MR visualization of early thrombus formation. B-227 14:54 Targeting MRP14: A novel approach for in vivo monitoring disease activity in rheumatoid arthritis M. Eisenblaetter1, T. Vogl1, P. van Lent2, J. Roth1, C. Bremer1; 1MГјnster/DE, 2 Nijmegen/NL ([email protected]) Purpose: Monitoring of early stages and of disease-activity in chronic rheumatoid arthritis is frequently impossible using conventional imaging approaches. Activated macrophages (M&) play a pivotal role in joint-inflammation and the expression of M& associated myeloid related proteins (MRP) has been shown to be strictly correlated with disease activity. The feasibility of MRP-Targeting using a MRP14-antibody labelled for fluorescence reflectance imaging (FRI) could be shown previously. This study was performed to assess the capabilities of MRP-targeting for monitoring disease-activity in experimental rheumatoid arthritis. Methods and Materials: Cy5.5 was either coupled to an MRP14-antibody or to immunoglobulin G serving as control for non-specific label distribution. Arthritis was induced in DBA/1 lacJ-mice by injection of bovine type-II-collagen at days 1 and 21. FRI was performed at day 26, 24 h after dye-injection and signal-to-noiseratios (SNR) were calculated. For correlation of imaging findings, clinical severity of the disease was assessed using a three-point-scale (CS0 - no clinical symptoms; CS2 - severe inflammation) and MRP-serum-levels were determined by ELISA. Data were statistically analyzed using one-way-ANOVA. Results: Mice presenting with equivalent clinical scoring of inflammation (CS2), revealed an approximately 2-fold higher SNR after anti-MRP14-Cy5.5 injection as compared to IGG-Cy5.5 (92.4 vs. 52.9; p 0.05). Mild clinical severity, proven by lower MRP-serum-levels (CS0: 840 ng/ml; CS1: 1170 ng/ml; CS2: 2910 ng/ml) correlated with lower anti-MRP14-Cy5.5-fluorescence in FRI (CS0: 39.4; CS1: 40.5; CS2: 92.4). Conclusion: Anti-MRP-Cy5.5 combined with FRI allows sensitive and specific detection of phagocyte-activity represented by MRP14-expression in vivo and can therefore be regarded a suitable probe for inflammatory activity in arthritis. B-228 15:03 MR imaging of magnetically labeled stem cells in cartilage defects T.D. Henning, E.J. Sutton, R. Meier, S. Tavri, T.M. Link, H.E. Daldrup-Link; San Francisco, CA/US ([email protected]) Purpose: To visualize Ferumoxides labeled human mesenchymal stem cells (hMSC) in cartilage defects by MR imaging at 3 T. Methods and Materials: hMSCs were labeled with Ferumoxides (100 Вµg Fe/ml) by transfection with Lipofectin. Viability was assessed by trypan blue exclusion and iron uptake was measured by spectrometry. 18 cartilage defects (3 mm) were created in porcine cadaver knees. In these defects, 2.2*105 Ferumoxides labeled cells in Surgifoam (Johnson&Johnson, n=6), 2.2 * 105 unlabeled cells in Surgifoam (n=6) or plain scaffolds (n=6) were implanted. All specimen were imaged in a clinical 3 T MR scanner, using T1SE, T2 FSE, SPGR and T2*-sequences. The signal intensity of scaffolds and cartilage was quantified as SNR and the contrast between these structures was quantified as CNR. Differences in between different scaffolds and in between pulse sequences were evaluated for significance by ANOVA. Histology of specimens was performed after MR imaging. Results: Cellular contrast agent uptake was 13.2 pg Fe/cell. No impairment of cell viability was found and histology documented cells in scaffolds. Signal intensity of the scaffolds was significantly different (p 0.05) from surrounding cartilage in all sequences. SPGR images showed the highest CNR of the labeled scaffold versus cartilage (79.1 p 29.1). On all sequences, CNR values between cartilage and transplants were higher for labeled cells compared to unlabeled cells and scaffold only. Conclusion: Implants with labeled hMSC showed a significantly higher CNR from surrounding cartilage than unlabeled cells. Therefore, the presented labeling protocol offers a simple and efficient technique for stem cell tracking using matrix associated cartilage implantation. A B C D E F G H S189 Friday synthesized and linked to specific ligands. Accumulation of targeted microbubbbles in tumors was quantified before and 36 h after HIT. Additionally, tumor vascularization was analyzed using high-frequency Doppler ultrasound. Results: In tumors accumulation of targeted microbubbles was significantly higher compared with non specific ones and could be inhibited competitively. Prior to treatment, no difference in binding of AvB3-Integrin-specific or ICAM-1-specific microbubbles was observed in treated and untreated animals. After irradiation, however, as compared to untreated controls there was a significantly higher binding of AvB3-Integrin-specific microbubbles and an enhanced binding of ICAM1-specific microbubbles. In both groups, a decrease in vascularisation occurred during tumor growth but no significant difference was observed between irradiated and non irradiated tumors. Conclusion: HIT upregulates ICAM-1 and AvB3-Integrin expression in tumor neovasculature. Molecular ultrasound can indicate the regulation of these angiogenic markers and thus helps to identify the optimal time point for the onset of antiangiogenic treatments after HIT in individualized therapy regimen. Scientific Sessions B-229 14:00 - 15:30 15:12 Somatic differentiation of magnetically labeled human embryonic stem cells T.D. Henning, S.E. Boddington, S. Taubert, P. Jha, S. Tavri, H.E. Daldrup-Link; San Francisco, CA/US ([email protected]) Purpose: To magnetically label human embryonic stem cells (hESC) with FDA-approved ferumoxides and to investigate the impact on their differentiation potential. Methods and Materials: hESC were labeled with Ferumoxides (100 Вµg Fe/ml). Viability was assessed by trypan blue staining. Contrast agent uptake was quantified by spectrometry. Intracellular iron deposition and cellular ultrastructure was investigated by transmission electron microscopy. Labeled and unlabeled hESC were examined for pluripotency by fluorescent staining for the markers SSEA-1, SSEA-2, TRA-60 and TRA-81. Somatic differentiation in embryoid bodies was quantified by RT-PCR for the markers hOCT4, hACTC1, hSOX1 and hAFP. Embryoid bodies of unlabeled controls and labeled hESC (n=3) were imaged over the time course of 21 days during undirected somatic differentiation. Imaging was performed at 3 T using T1SE, T2SE and T2*GE-sequences and SNR were compared for significant differences. Results: Contrast agent uptake was 1.4 pg Fe/cell. No significant decrease in cell viability was found (p 0.05). Electron microscopy showed cytoplasmic storage of iron oxide-particles in lysosomes. Fluorescent microscopy confirmed retained pluripotency of labeled cells. RT-PCR of embryoid bodies showed up to 189-fold induction of somatic germ layer markers and a 7-fold decrease of the embryonic marker. Embryoid bodies of labeled hESC showed a significant T2-effect on T1weighted and T2-weighted images and a significant T2*-effect on T2*-weighted images (p 0.05). After somatic differentiation for 21 days, embryoid bodies still showed significant contrast agent effects (p 0.05). Conclusion: After labeling with Ferumoxides, hESC retain pluripotency and differentiation potential. A contrast agent effect persists after differentiation for at least 21 days. B-230 15:21 In vivo MR evaluation of effect of CCR2 antagonist on macrophage migration Y. Lee, J. Ryu, J. Sohn, H. Jang, J. Lee; Seoul/KR ([email protected]) Purpose: The main aim of this study is to evaluate the feasibility of in vivo MR imaging for assessing the inhibition of chemoattractant activity by CCR2 antagonist and pertussis toxin. Methods and Materials: Cell motility was investigated as in vitro migration of cells to MCP-1 mixed with Matrigel matrix on 4-well chamber slide. For in vivo evaluation, experimental soft-tissue infection in 12 mice was induced by inoculation with a 5 X 107 colony-forming unit of Staphylococcus aureus into the left calf. After treating macrophges with PBS (negative control group), CCR2 antagonist (antagonist group), and pertussis toxin (positive control group), iron oxide labeled macrophages (RAW 293.7) were injected through the tail vein. The left calf of the mice was imaged on a 4.7 T MR unit on day 3. The changes in relative signal intensity (SI) and the pattern of contrast enhancement (macrophage distribution) were analyzed and compared with histopathologic findings. Results: In migration test with chamber slide, macrophages treated with CCR2antagonist showed significantly decreased chemotatic migration compared to wild type macrophages. On MR images 24 hours after administration of macrophage labeled with iron oxide, the band-shaped lower SI zone was noted in the abscess wall. MR Signal intensity of the abscess wall significantly decreased in antagonist group than negative control group but increased than positive control group. Conclusion: CCR2 antagonist can block the CCR2 on macrophage and decrease the chemotactic activity of macrophage toward MCP-1. In vivo MR imaging successfully demonstrate the effect of CCR2 antagonist to macrophage migration. S190 A B C D E F G F H Room P Chest SS 304 Pulmonary embolism and hypertension Moderators: G. Bastarrika; Pamplona/ES D. Hahn; WГјrzburg/DE B-231 14:00 Minimizing contrast medium (CM) doses by using 80 kVp 16-MDCT to diagnose acute pulmonary embolism (PE) in patients with moderate to severe renal impairment M. Kristiansson, S. Wettemark, L. Nilsson, U. Nyman; Trelleborg/SE ([email protected]) Purpose: To report on further CM dose reduction from 200 (ECR-abstract 2007) to 150 mg I/kg (25% reduction) relative CM doses in a 16-MDCT survey (28-56 gram iodine, i.e. 400-800 mg I/kg in a 70 kg individual) by using 80 kVp, bolus tracking, constant injection duration adapted to scan time and saline chaser. Methods and Materials: A total of 89 (38-100 kg) and 50 (41-84 kg) consecutive patients with suspected PE and estimated GFR 50 mL/min underwent 80 kVp 16-MDCT (350 reference effective mAs; Siemens CareDose) after injecting 200 mg I/kg during 15 seconds (13.3 mg I/kg/s) and 150 mg I/kg during 12 seconds (12.5 mg I/kg/s), respectively, with a maximum dose weight of 80 kg and combined with bolus tracking (100 HU enhancement threshold, 5 second scan delay) and 50 mL saline chaser. Mean density, image noise (1 standard deviation), contrast-to-noise ratio (assuming 70 HU for a fresh clot) of the left main pulmonary and a lower lobe segmental artery were calculated on 3 mm thick slices. Results: The following median values (2.5-97.5 percentiles) were obtained in the 200/150 mg I/kg cohorts: CM dose 13.1/9.6 (8.2-16.0/6.4-12.8) gram iodine, density 351/353 (199-563/164-488), HU and CNR 12/11 (6-26)/(4-22); PE incidence 22%/16% and 6%/8% on subjectively suboptimal examinations, but none classified as nondiagnostic. All values were within those reported for common 16-MDCT protocols. None of the 111 patients with plasma creatinine follow-up within 1 week experienced contrast-induced nephropathy (plasma creatinine rise r44 Вµmol/L). Conclusion: In patients at risk of contrast-induced nephropathy 80 kVp-MDCT may be performed with markedly reduced CM doses and preserved diagnostic quality compared with reported 16-MDCT standards. B-232 14:09 Does 80 kVp pulmonary CT angiography deliver sufficient image quality in patients weighing up to 100 kg? Z. Szucs-Farkas, T. Strautz, L. Kurmann, M.A. Patak, P. Vock, S.T. Schindera; Berne/CH ([email protected]) Purpose: To assess if diagnostic quality is sufficient with pulmonary CT angiography (CTA) using 80 kVp in patients weighing up to 100 kg or a lower threshold of body weight (BW) should be applied. Methods and Materials: A total of 100 patients weighing less than 100 kg (range, 44-99 kg; mean, 70.6 kg) with suspected pulmonary embolism were examined with CTA using 80 kVp and reference mAs of 150 after injecting 75 mL contrast medium at 3 mL/s. Attenuation in the pulmonary arteries and noise were measured, and the contrast-to-noise ratios (CNR) were calculated. Three radiologists independently analyzed the overall image quality, the most distal detectable ramification of the pulmonary vessels and the noise and arterial enhancement in each pulmonary artery on a five-grade scale. Patients were grouped by BW into 6 groups (group 1: 0-50 kg BW; groups 2-6: 51-100 kg BW, decimally increasing). Quantitative and qualitative image parameters between the groups were compared by the analysis of variance and post-hoc tests. Results: No significant difference was found in the measured image noise between patient groups above 50 kg (P = 0.387-1.0). CNR in patients weighing 71-80, 81-90 and 91-100 kg did not differ significantly (P = 0.116-1.0). There was no significant difference between all the patient groups in the subjective ranking of enhancement (P = 0.165-0.605), detectable ramification of the pulmonary arteries (P = 0.656), subjective grading of noise in the vessels and mediastinum (P = 0.063 and 0.094, respectively) and overall image quality (P = 0.079). Conclusion: An 80 kVp pulmonary CTA permits sufficient diagnostic image quality in patients weighing up to 100 kg. Scientific Sessions B-233 14:18 MDCT angiography of the pulmonary arteries using very low dose (40 cc) of highly concentrate contrast media V. Schembri, S. Lenel, J. Lonjon, H. Vernhet, S. Aufort, B. Gallix, J.-M. Bruel; Montpellier/FR ([email protected]) B-234 14:27 Dual energy CT for the diagnosis of pulmonary embolism: CT angiography versus iodine map R.W. Bauer, M. Kerl, P. Weisser, H. Korkusuz, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: To evaluate the correlation of CT angiographic findings and perfusion defect as assessed with Dual Energy CT (DECT) in the diagnosis of pulmonary embolism (PE). Methods and Materials: 25 consecutive patients underwent DECT angiography for suspected PE. Scan protocol was as follows: tube voltage/current on tube A 140 kV/70 mAs, on tube B 80 kV/297 mAs, collimation 14x1.2 mm, slice thickness 1.5 mm. CTA data were assessed for the presence of emboli by two experienced readers in consensus. Based on the dual energy characteristic of iodine at the two different X-ray spectra, a color-coded iodine distribution map of the lung parenchyma was calculated. This map was assessed for emboli-typical wedge-shaped areas of reduced iodine content, i.e., perfusion defects (PD), by another two readers in consensus who were blinded to the CTA results. Correspondence of the results was assessed by calculating sensitivity and specificity on a per-patient and persegment basis. Results: 23 segments in 8 patients showed pulmonary embolism on CTA, of which 20 segments in 7 patients showed corresponding PD, representing an 88/87% sensitivity and 94/99% specificity on a patient/vessel-based analysis. 3 segments with no PD showed non-occlusive clot formation on CTA. Conclusion: Areas of the lung parenchyma with reduced iodine content on DECT showed good correlation to the presence of emboli in the respective vascular territory. Both the morphological correlate of suspected PE and its hemodynamic significance can be demonstrated with the data acquired with a single DECT scan. B-235 14:36 Dual energy CT pulmonary angiography: Initial experience in 30 patients with pulmonary arterial hypertension N. Screaton, E.T.D. Hoey, N. Qureshi, V. Ganesh, B. Agrawal, A.D. Tasker, D. Gopalan; Cambridge/UK ([email protected]) Purpose: To identify dual energy CT (DECT) perfusion patterns in patients with different causes of pulmonary arterial hypertension. Methods and Materials: 30 consecutive patients with pulmonary hypertension referred for CT pulmonary angiography underwent DECT angiography with the following parameters: Tube A 140 kV, Tube B 80 kV, 500 ms rotation, pitch 0.5. Fused gray-scale images were reconstructed (70% 140 kV, 30% 80 kV) with 1.5 mm section thickness. Iodine distribution maps were generated using pulmonary blood volume software and overlaid on the gray-scale image. Each case was analysed by 2 cardiothoracic radiologists by consensus and assigned a predominant perfusion pattern according to a predetermined descriptive scale: normal perfusion, B-236 14:45 Computer-aided detection of pulmonary embolism at pulmonary CT angiography: Can it improve sensitivity of inexperienced readers? K.N. Blackmon1, C. Florin2, H. Lee1, L. Bogoni2, P. Kogos1, J. Koonce1, R. Coursey1, P. Costello1, U.J. Schoepf1; 1Charleston, SC/US, 2Malvern, PA/US ([email protected]) Purpose: To evaluate the effect of a computer-aided detection (CAD) prototype on the sensitivity of novice readers for detection of pulmonary embolism (PE) at pulmonary CT angiography (CTA). Methods and Materials: Forty-one consecutive CTA examinations clinically identified as positive for PE and 43 consecutive CTA examinations initially identified as negative were included. Studies were evaluated in a randomized, blinded fashion by two independent inexperienced readers who marked all vessels containing PE. After 3 months, all studies were reevaluated by the two inexperienced readers, this time aided by the CAD prototype. A consensus read by two expert radiologists served as the reference standard. Results: Expert consensus revealed 294 PEs (20 central, 2 lobar, 264 segmental, and 8 subsegmental) in 41 patients. Inexperienced readers’ initial reads had an average sensitivity of 23.13% on a per-PE basis, which improved to 45.24% with CAD (p 0.001). False positives increased from 0.52 to 0.81/case. Of note, the sensitivity of the CAD prototype averaged 82.65% (5% central, 50% lobar, 90.15% segmental, 37.5% subsegmental). On a per-patient basis sensitivity increased 12.2% (27.5/41 true positives without CAD and 32/41 true positives with CAD; p 0.001) and false positives increased 1.75% with CAD (2/43 false positives without CAD and 3.5/43 with CAD). With CAD, the number of false negative patients was reduced from 15 to 10. Conclusion: CAD significantly improves sensitivity of PE detection for inexperienced readers with a small but appreciable increase in the rate of false positives. Thus, CAD may improve clinical management of patients, e.g. in on-call situations. B-237 14:54 Evaluation of stand-alone detection performance of a prototype pulmonary emboli (PE) CAD system across multi-vendor and multi-center MDCT data S. Lakare1, M. Dinesh2, S. Mansur2, D. Desai3, A. Luthra4, J. Schoepf5, M. Das6, D. Naidich7, M. Salganicoff1; 1Malvern, PA/US, 2Bangalore/IN, 3Mumbai/IN, 4 Pune/IN, 5Charleston, SC/US, 6Aachen/DE, 7New York, NY/US ([email protected]) Purpose: To evaluate the potential variability of detection accuracy of a prototype PE-CAD system on MDCT cases acquired from institutions, scanner models/ vendors different than those used in the development. Methods and Materials: The PE-CAD system was developed with cases primarily acquired from scanners manufactured by Siemens. For this study, 73 new cases were acquired from five hospitals across three continents, referred for CTPA to rule-out PE. Group 1 (G1, N1 = 50) contained cases from scanners manufactured by Siemens (Volume Zoom = 1; Sensation16 = 20; Sensation 64 = 11;Cardiac Sensation 64 = 18) acquired at 3 sites, in US, Europe and Asia. Group 2 (G2, N2 = 23) had cases from Philips scanners (Brilliance 40 = 11; Brilliance 64 = 12) acquired at 2 Asian sites. G1 had 60 emboli; 54 in lobar/segmental/sub-segmental (LSS) region. G2 had 40 emboli; 28 in LSS. The contrast uptake (pulmonary trunk) varied from 100 - 500 HU (mean 375 HU). Results: For G1, per-PE sensitivity was 91.7% for all PE and 92.6% for LSS PE; average FP was 2.9/case. For G2, 87.5% for all PE; 89.3% for LSS PE; average FP of 1.8/case. The per-PE sensitivity across all 73 cases was 90% for all PE and 91.5% for LSS PE with FP of 2.6/case (mean) and 2/case (median). For 7 cases (10%) with normal ground-truth, our system had zero detections. A B C D E F G H S191 Friday Purpose: To compare very low dose of high-concentration iodine contrast media and high dose of standard contrast media on attenuation and visualization of the pulmonary arteries in thoracic MDCT angiography. Methods and Materials: 190 patients referred to our department for suspected acute pulmonary embolism underwent MDCT angiography either with 40 cc of high-concentration iodine contrast media (400 mgr/l) followed by 40 cc of saline solution (GROUP A), or with 120 cc of standard concentration iodine contrast media (350 mgr/l) when imaging of the abdomen and pelvis was performed during the same examination (GROUP B). In both groups, the scan delay was determined using automatic bolus tracking system. Flow rate and scanning parameter were identical in both groups. Quantitative analysis was made by region of interest measurement in pulmonary arteries (main, lobar, segmental and sub-segmental arteries) to compare the attenuation profiles of the two groups. Results: The mean enhancement was 356 and 308 HU (p 0.05) for groups A and B, respectively, in the main arteries; 343 and 298 HU (p 0.01) in the lobar arteries; 326 and 284 HU (p 0.05) in the segmental arteries; and 286 and 256 HU (p=0.08) in the sub-segmental arteries. The mean attenuation of the first, second, third and fourth-order arteries was 327 HU in group A and 286 HU in group B (p 0.03). Conclusion: A very low dose of high iodine concentration contrast media significantly increase pulmonary arteries enhancement compared to standard MDCT protocol. peripheral wedge shaped defects, mottled dot like defects, fine lace like defects and unclassifiable defects. Results: 15 patients had chronic thromboembolic disease, 5 idiopathic pulmonary hypertension, 3 pulmonary fibrosis, 3 congenital left to right shunt, 2 left heart disease and 2 emphysema. Peripheral wedge shaped defects were seen in 12 patients with thromboembolic disease and none of the other groups. Mottled dot like defects were seen in 4 patients with idiopathic pulmonary hypertension and 2 with congenital left to right shunt. Fine lace like defects were seen in all those with pulmonary fibrosis. The remaining 9 patients had an unclassifiable pattern. Conclusion: DECT perfusion patterns seem to correspond with expected pathoanatomic alterations of disease state. DECT appears most useful in those with chronic thromboembolic and idiopathic pulmonary hypertension and may obviate the need for ventilation/perfusion scinigraphy following validation in large scale trials. Scientific Sessions Conclusion: The prototype system showed uniformly high sensitivity and low FP rate across scanners from diverse vendors and models, and different geographic sites world-wide. The results provide important confirmation on the reliability of such systems as an adjunct to primary reads in a routine clinical environment at multiple institutions where acquisition devices may vary. B-238 15:03 Diagnostic accuracy of real-time MRI, MR perfusion imaging, MR angiography and cardiac volumetric measurement in acute pulmonary embolism compared with MDCT M. Schlieter, S. Ley, T. Heye, H.-U. Kauczor, W. Hosch; Heidelberg/DE ([email protected]) Purpose: To assess the diagnostic accuracy of MRI compared with the reference standard MDCT for detecting acute pulmonary thromboembolism; to assess the quantification of pulmonary blood flow and volume by contrast-enhanced dynamic magnetic resonance imaging using a parallel imaging technique and to prove the feasibility of MRI in the detection of acute pulmonary embolism (PE). Methods and Materials: 36 patients with suspected PE were first examined with CT and afterwards transferred to the MR unit. A MR protocol combining real-time MRI using true fast imaging with steady-state precession, half Fourier single shot fast spin echo, 3 D fast low angle shot, generalized autocalibrating partially parallel acquisition technique (acceleration factor 2), volumetric interpolated breath-hold examination and cardiac volumetric measurements were performed. Results: PE was diagnosed in 24 of the 36 patients who completed the MR protocol. Perfusion MR revealed significant differences in mean transit time and time to peak values, relative regional pulmonary blood flow and relative regional pulmonary perfusion of areas affected by PE. The sensitivities of real-time MRI, MR angiography, MR perfusion imaging, and the combined protocol were 83, 75, 100, and 100%, respectively. The specificities were 96, 100, 89, and 91%. Cine MR revealed a paradoxical movement of the interventricular septum in 4 cases. Conclusion: The combined MR protocol for the detection of PE is reliable and diagnostic equivalent in comparison to MDCT. MR perfusion imaging is sensitive for the detection of pulmonary embolism, whereas real-time MRI and MR angiography are specific. B-239 15:12 Contrast-enhanced MR imaging of pulmonary arteries: New imaging strategies with a blood-pool contrast agent M.R. Makowski1, A.J. Wiethoff1, A. Bell1, V. Parish1, R.M. Botnar1, M. Rohrer2, R. Razavi1, T. Schaeffter1, G. Greil1; 1London/UK, 2Berlin/DE ([email protected]) Purpose: First-pass breathhold non-ECG-triggered 3D contrast-enhanced magnetic-resonance angiography (CEMRA) is commonly used for the assessment of the pulmonary arteries. However, using conventional extracellular contrast agents, image resolution is limited by time constraints and borders are blurred due to vascular motion and insufficient breath holds. Pulmonary vascular imaging using a respiratory-gated and ECG-triggered 3D contrast-enhanced IRprepulse sequence in combination with Gadofosveset (mean intravascular t1/2A = 0.48 p 0.11 h) and 32-channel coil technology is introduced and compared to breathhold 3D-CEMRA. Methods and Materials: In eight subjects (29 p 6 yrs) with normal pulmonary vasculature, CEMRA was performed on a 1.5 T clinical scanner (Philips Medical Systems) using 32-channel cardiac coil for fast imaging (SENSE = 4) and optimal coverage. Patients were investigated twice using gadopentetate dimeglumine (day1, 0.10-0.17 mmol/kg), and gadofosveset trisodium (day 2, 0.03 mmol/kg, Bayer-Schering Pharma AG). CEMRA as well as a respiratory navigator-gated and ECG-triggered steady-state free-precession (SSFP) sequence with a T2-prepulse was used. An IR-prepulse to suppress surrounding tissue signal was applied with gadofosveset trisodium. Results: Significantly (P 0.05) better results (mean p SD) were achieved for the high-resolution navigator-gated and ECG-triggered 3D-IR-SSFP sequence using gadofosveset with regard to CNR (153 p 24 vs 89 p 37), vessel length (186 p 28 mm vs 136 p 42 mm) and vessel wall sharpness (47 p 5% vs 33 p 6%) compared to 3D-CEMRA using Gd-DTPA. Gadofosveset did not improve the image quality in the 3D-SSFP technique without IR compared to Gd-DTPA and 3D-CEMRA. Conclusion: Pulmonary vascular imaging using a navigator-gated and ECGtriggered 3D-IR-SSFP sequence with gadofosveset and 32-channel-coil technology yielded significantly higher morphologic detail compared to breathhold CEMRA and 3D-SSFP without IR. This technique has the potential to improve diagnostic imaging of the pulmonary vasculature. S192 A B C D E F G F H B-240 15:21 Mean pulmonary arterial pressure estimation by phase-contrast MR imaging in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and correlation with simultaneous invasive pressure recordings: First results K.-F. Kreitner, R. Kunz, S.A.H. Herber, E. Mayer, C. DГјber; Mainz/DE ([email protected]) Purpose: To estimate mean pulmonary arterial pressure (mPAP) in patients with CTEPH by analysing flow parameters of the pulmonary trunc derived from high temporal resolution phase-contrast MR imaging (PC-MRI). Methods and Materials: We prospectively examined 7 CTEPH patients with high temporal resolution PC-MRI at 1.5 T (Magnetom Sonata В®, Siemens Medical Solutions) with simultaneous invasive pressure recordings in the pulmonary trunc. Imaging parameters for PC-MRI were as follows: TR = 10 msec, TE = 2.5 msec, Flip = 15В°, velocity encoding = 100 cm/sec, bandwidth = 977 Hz/pixel, 3 averages. The parameters absolute and relative acceleration time ATa [mesc] and ATr [%], peak of mean velocities MRV [cm/sec], and distensibility DIS [%] were evaluated according to Proc. Intl Soc Mag Reson Med 2003; 11: 407, and were used to compute mPAP with the following regression equation: mPAP-PC-MRI [mmHg] = 88.9- 0.29 * ATa - 1.1 * ATr - 0.38 * MFV - 0.16 * DIS. Results: MPAP-MRI correlated very well with simultaneous invasive pressure recordings in all patients (linear coefficient of determination R2 = 0.979, p 0.001, median difference +2.0 mm Hg, range -1.9 - + 4.7 mm Hg). Conclusion: Non-invasive mPAP-estimations are possible in CTEPH-patients by means of high temporal resolution PC-MRI and correlate well with simultaneous invasively measured values. 14:00 - 15:30 Room Q Interventional Radiology SS 309 Musculoskeletal interventions Moderators: A. Feydy; Paris/FR A.L. Jacob; Basle/CH B-241 14:00 Percutaneous treatment of contained disk herniations: Comparison among three techniques S. Marini, S. Marcia, M. Marras, G. Mallarini; Cagliari/IT ([email protected]) Purpose: This study was to compare three different techniques employed for percutaneous treatment of contained disk herniations in order to evaluate their benefits and pitfalls. Methods and Materials: In our study, we evaluated 747 consecutive patients by using in 305 nucleoplasty (NP), in 261 percutaneous laser disk decompression (PLDD) and in 181 mechanic decompression with Dekompressor device (DK). We performed on all patients with local anaesthesia. We always used discography before performing each procedure. For each patient, 1 week, 3 months, 6 months and 12 months outcomes were assessed by their treating physicians and support staff. Success was defined as a minimum 2-points reduction on a visual analog pain scale. Results: Overall success rate in pain reduction was 72 and 84% at 1 week and 12 months by using NP (prepost procedure VAS 4.03, p=0.001). Success rate in pain reduction was 73 and 81%, for 1 week and 12 months by using PLDD (prepost procedure VAS 3.87, p=0.001). Rate in pain reduction was 71 and 81%, for 1 week and 12 months by using DK (prepost procedure VAS 3.94, p=0.001). Before the treatment 77% were used to having analgesic, after the treatment only 28% patients required it. Conclusion: Results of our data suggest that the use of NP, PLDD and DK for treatment of contained disk herniations may be all optimal therapeutic options showing high success rates. For their safety, efficacy and feasibility, all these procedures for percutaneous treatment of contained disk herniations have a wide application in clinical practice. Scientific Sessions B-242 14:09 Purpose: To evaluate safety and efficacy of percutaneous intervertebral disk decompression (PDD) in the reduction of discogenic pain associated with disk herniation. Methods and Materials: During the last 3 years, a total of 33 intervertebral discs were treated with fluoroscopically guided PDD. Indications included cervicobrachialgia, sciatica with/without lumbago and intervertebral disc herniation confirmed in MRI with no neurologic deficit. Diminished disk height was noted in 7/31 patients. Pain was assessed with preoperative pressure discography. Under local anesthetic (Lidocaine Hydrochloric 1%, 20 cc) and Fluoroscopy, PDD was performed with 17G Dekompressor, on positive discographies. Prophylactic antibiotics were administrated. Clinical evaluation included immediate and delayed follow-up studies of patient’s general condition and neurological status. An AVS scale on a questionnaire adapted to Greek population helped assessing pain relief degree, life quality and mobility improvement. Results: Patients were prospectively followed for 24 months with respect to pain reduction and mobility improvement. Comparing patients’ scores prior (mean value 7.4 p 1.4 AVS units) and after (mean value 1.6 p 2.4 AVS units) treatment, patients included in our study presented a mean decrease of 5.8 p 2.4 AVS units (p b 0.001) on terms of life quality improvement and pain relief. No complication was observed. Six out of 8 patients with minimum improvement had reduced disc height. Pain reduction was significant in 26/31 patients (83.7%). Conclusion: PDD seems to be an efficient and safe technique for the therapy of intervertebral disc herniation. Discs with decreased height had partial pain relief. Pressure discography is a useful tool. No complication was noticed. B-243 14:18 Pathological change in lumbar discs of goat after computed tomographyguided percutaneous intradiscal ozone injection Z. Lin1, S. Lin2, Y. Dai1, S. Ye1, Y. Huang1, G. Li1, C. Chen1; 1Fuzhou/CN, 2Fuan/CN ([email protected]) Purpose: To investigate the pathological change in lumbar discs of goat after CTguided percutaneous intradiscal ozone3 injection. Methods and Materials: Under the guidance of CT, 3 ml ozone (50 Вµg/ml) was injected into L4/5 and L5/6 intervertebral discs with 22G Chiba needle in six goats. Conventional MRI scan (FSE T1WI and FSE T2WI) were performed after injection. The goats were evenly divided into 3 groups, and were sacrificed for pathology one week (group 1), one month (group 2) and two months (group 3), respectively, after the procedure. After MRI examination, the specimens were observed macroscopically and microscopically. Results: The findings of post-procedure scan: the air was distributed intra- and para- discs on CT and MRI images. No serious behavior abnormalities were observed in all animals. On FSE T2WI images of group 2 and group 3, the signal intensity of nucleus pulposus were attenuated in 4 discs. In group 1, the matrix of nucleus pulposus was slightly edema. In group 2 and group 3, the atrophy of nucleus pulposus and extensive proliferation of collagenous fiber was found. Under the electron microscope, the samples of groups 2 & 3 demonstrated that a large number of cells were necrosis, the neucli were lysis, the oraganelle and glycogen was decreased obviously. Conclusion: CT-guided percutaneous intradiscal ozone injection can lead gradually to atrophy and fibrosis of nucleus pulposus. It was a minimally invasive, safe and effective treatment for the intervetebral disc herniation. B-244 14:27 Percutaneous radiofrequency neurotomy is effective in the treatment of lumbar facet joint syndrome S. Marcia, S. Marini, M. Marras, G. Mallarini; Cagliari/IT ([email protected]) Purpose: Lumbar medial branch neurotomy has been applied in the treatment of facet joint syndrome by means of percutaneous radiofrequency denervation (RFD). The data so far available on its efficacy is still controversial because of the differences in patient selection and surgical technique. The aim of this study was to provide new evidence on the clinical outcome of this procedure. Methods and Materials: A total of 45 patients (mean age 70.3 p 13.0) with chronic low back pain due to facet joint syndrome were selected for RFD. The diagnosis was confirmed by gadolinium MRI and local anesthetic injection close to the zygapophysial symptomatic joints. Electrical stimulation of the medial branch nerve B-245 14:36 Percutaneous vertebroplasty with or without endovascular embolisation in vertebral haemangiomas: Analysis of 56 cases N.K. Bodhey, A.K. Gupta, T.R. Kapilamoorthy, C. Kesavadas, H.S. Pendharkar, S.N. Patro, A. Periakaruppan; Trivandrum/IN ([email protected]) Purpose: Vertebral haemangiomas are a major cause of nondiscal backache. The aim is to study the efficacy of endovascular embolisation and vertebroplasty and long-term results. Methods and Materials: Sixty-two vertebral haemangiomas were treated in 56 patients (22 males, 34 females) with age between 13 and 75 years. Presentation was only backache in 35, additional paraparesis in 15 and rest had paraplegia. Those with significant neurodeficit had thecal compression on imaging. Surgical intervention was also contemplated in 8 patients due to this compression. Selective endovascular embolisation was done in 49 patients with Polyvinyl-alcohol particles. Vertebroplasty with bone cement was done in all patients through a bone biopsy needle introduced under fluoroscopic guidance. The results were analysed with respect to pain relief, reduction in analgesic usage and improvement in the neurodeficit. Results: Majority of the haemangiomas were located in the dorsolumbar region. The filling of the vertebrae with bone cement ranged between 60 and 90%. There was significant pain relief in those presenting with backache. Paraparesis due to mild thecal compression was relieved due to shrinkage of the extradural soft tissue in 15 patients. Improvement in the grade of weakness was seen in 3 out of 6 with paraplegia, yet required surgical decompression for total relief. Procedure-related complications of leaking bone cement compressing the thecal contents were seen in 3 patients with deficient posterior cortex. Conclusion: The haemangiomas require a combined therapy with embolisation and vertebroplasty for effective strengthening of the vertebrae specially so when a surgical adjunct is contemplated. B-246 14:45 Treatment of osteoporotic spine fractures with percutaneous vertebroplasty: Influence on health-related quality of life, frequency of adjacent fractures and prospective assessment of fracture healing O.T. Ertl, R. Fessl, K. Bohndorf; Augsburg/DE ([email protected]) Purpose: We quantified the positive effects of percutaneous vertebroplasty on health-related quality of life. We documented the occurence and location of adjacent fractures and prospectively assessed the evolution of fracture edema. Methods and Materials: A total of 67 osteoporotic spine fractures were treated in 48 patients. Pain intensity (VAS) was documented before and 1 day and 3 months post-intervention. Health-related quality of life was measured using the SF 36 questionnaire and paired t-test. Fracture edema and frequency of adjacent fractures were prospectively assesed in sequential pre- and post-treatment MRI. Results: Vertebroplasy led to a significant reduction in pain level from VAS 7.1 before intervention to VAS 3.1 one day post-intervention. Health-related quality of life concomitantly increased, as shown in particular by the SF 36 score for “bodily pain” (12.4 vs. 53.7, P 0.001). After 3 months, 20 patients showed increasing pain levels. The reason was given as either continuous decrease in vertebral height, new osteoporotic fractures or coexistent disease. Fracture edema persisted in 36% of treated vertebral bodies without being associated with increased pain levels. Among the 23 new fractures observed, 12 were in the proximity of the treated vertebral body, whereas 11 were distant. Conclusion: Percutaneous vertebroplasy led to fast pain reduction and to a sustained increase in health-related quality of life. Persistent fracture edema after 3 months was seen in 1/3 of cases. There was no association with increased pain levels. New fractures in the proximity of treated vertebral fractures did not occur more frequently than elsewhere. A B C D E F G H S193 Friday Percutaneous intervertebral disc decompression: Prospective study for pain evaluation D.K. Filippiadis, D. Erginousakis, N. Ptohis, E. Brountzos, N.L. Kelekis, A.D. Kelekis; Athens/GR ([email protected]) area with measurement of impedance was also performed in order to determine the proper site of intervention and to avoid motor nerve lesion. Clinical evaluation and assessment of pain by means of a visual analog scale (VAS, 0-10) was performed before, 1 week, 1 month, 6 months and 12 months after the RFD procedure. Results: A total of 54 joints were treated in the 45 patients enrolled in the study. Baseline pain VAS was 8.6 p 1.1, while 12 months after RFD was 5.6 p 2.1 (p 0.0001, Mann-Whitney test). Only 14% of patients reported no improvement 3 months after RFD, while 24% of patients were still on analgesic drugs (compared with 100% before treatment). No side effects were reported. Conclusion: Lumbar medial branch neurotomy by means of RFD is an effective and safe procedure in reducing chronic back pain in patients with facet joint syndrome. Scientific Sessions B-248 14:54 Percutaneous cryoablation in bone painful metastases D. Bartolucci1, M. Mammucari2, F. Massari2, S. Masala2, G. Simonetti2; 1Terni/IT, 2 Rome/IT Purpose: Approximately 70% of patients with cancer have evidence of metastatic disease at death. Skeleton represents the most common site of tumor metastasis. Approximately 50% of metastases arise from one of these primary types of cancer: breast, lung, prostate or melanoma. The aim of this study is to determine the safety and effectiveness of percutaneous cryoablation in pain reduction, daily life activities improvement and reduction in the use of analgesics for patients with bone painful metastatic lesions. Methods and Materials: We treated with percutaneous cryoablation, during a 17 months period, 27 patients (17 men, 10 women; age range, 38-72 years; mean age, 52 years) with one or more painful metastatic lesions involving bone, with positive visual analogue scale (mean score: 7.8), who did not respond to conventional radiation treatment or chemotherapy. Results: Postprocedural evaluation confirmed reduction of the VAS (mean score: 3.9). Treated lesions were 1-9 cm in maximum diameter. There was a marked increased in activities of daily living and reduction in narcotics utilization. No serious complications were observed in our study. Conclusion: Painful bone metastasis commonly occurs in advanced cancer patients. They are difficult to manage because of pain, reduction of mobility and performance status. In secondary bone tumors, few patients are surgical candidates, and so current treatments are aimed to pain palliation. Standard treatments include radiation therapy, chemotherapy and analgesics. Percutaneous cryoablation is a safe and effective method for palliation of pain due to metastatic disease involving bone. B-249 15:03 Percutaneous CT-guided radiofrequency ablation of osteoid osteoma with multitined expandable electrodes R. Cioni, E. Bozzi, L. Crocetti, V. Zampa, C. Bartolozzi; Pisa/IT ([email protected]) Purpose: To determine the feasibility, safety and effectiveness of percutaneous CT-guided radiofrequency ablation (RFA) of osteoid osteoma (OO) with multitined expandable electrodes. Methods and Materials: Thirty-three patients (age 4-60 years) with single OO (27 long bones, 2 vertebrae, 2 calcaneum, 2 hips) were enrolled in a prospective, single center, single-arm clinical trial. Diagnosis was obtained by clinical and imaging findings in 29 patients and by CT-guided biopsy in 4 patients. CT-guided RFA was performed under conscious sedation or nerve block anesthesia with a 150-200 W generator and expandable multitined electrodes (RITA Medical Systems). Distance from lesion to skin ranged from 1 cm to 9 cm (mean: 5.1 cm p2.5). Follow-up period ranged 6-58 months (mean: 30 months p 15) and included MR examinations and clinical visits performed 6 months after the procedure and at 12-month intervals thereafter. Results: RF ablation was technically feasible in all 33 patients (technical success 100%). No major complications, in particular no skin burns, occurred. Pain relief and complete ablation of the nidus, as shown by the 6-month MR, was achieved in 29/33 OOs (primary effectiveness rate 88%). In 4 patients, recurrence of pain and persistent contrast uptake of the nidus at MR were present. The OOs were effectively re-treated by means of RFA (secondary clinical success 100%). No recurrences were observed on follow-up. Conclusion: Percutaneous CT-guided RFA of OO performed with multitined expandable electrodes is feasible and safe. It yields prompt pain relief and return to normal activities in a high rate of patients with OO. B-250 15:12 Percutaneous iliosacral screw placement using CT fluoroscopic guidance R.-T. Hoffmann, T. Jakobs, C.G. Trumm, S. Piltz, T.K. Helmberger, M.F. Reiser; Munich/DE ([email protected]) Purpose: The purpose of this prospective study was to evaluate feasibility, safety, time consumption and short-term complications of CT-fluoroscopic guided pelvic fracture fixation. Methods and Materials: Within 42 months 48 patients were referred for unstable fractures of the posterior pelvic ring. Fourteen out of 48 patients suffered from bilateral fractures of sacrum or sacroiliac joint and in 34 of 48 patients screws were placed in S1 and/or S2 to create rotational stiffness. Length of screws and exact entry point was defined on CT. After small skin incision, K wires were placed into sacral bone under CT fluoroscopic guidance using a surgical hammer. After exact S194 A B C D E F G F H placement of K-wires a surgical drill was used to make the placement of the canulated, self-drilling screws possible. After placing screws, control scan was performed to prove exact position of the screws and to rule out early adverse events. Results: Sufficient screw placement was possible in all patients. No treatment related minor or major complications occurred. Time between the first CT-scan and end of procedure was 24 minutes (18-48) in patients with the need of a single sided treatment and 75 minutes (45-105) in patients with treatment of both sides. Conclusion: The screw-fixation of unstable fractures of the posterior pelvic ring under CT fluoroscopy is feasible with no significant complications. The exact visualization and ease of screw placement enables a significant reduction of treatment duration and is therefore advantageous for heavily injured patients. 14:00 - 15:30 Room R Cardiac SS 303 Cardiomyopathies Moderators: F. Knollmann; Pittsburgh, PA/US J.-P. Laissy; Paris/FR B-251 14:00 Late gadolinium enhancement compared to histology of autoimmune experimental myocarditis in an animal model H. Korkusuz, P. Esters, N.-E.A. Nour-Eldin, E. Mbalisike, N. Naguib, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: To study if a rat model of experimental autoimmune myocarditis (EAM) can be verified by a clinical 1.5 T MR magnet and to investigate late gadolinium enhancement (LGE) pattern in EAM. Methods and Materials: A total of 10 male Lewis rats, aged 6-8 weeks were immunized with porcine cardiac myosine on days 1 and 7, while 10 animals served as control. On day 21, the animals were investigated by cardiovascular magnetic resonance imaging (CMR). CMR examination was performed by ECG-triggered gradient-echo (GRE) sequences of beating heart and by turbo-spin-echo (TSE) sequences of stagnant heart. Results: In the experimental group, eight animals survived and developed myocarditis, while the control group animals were healthy. Only animals in the experimental group (n = 8) revealed LGE after gadolinium injection. The mean percentage of late enhancement area detected by GRE sequences was higher at reduced heart rate (25.93% p 23.6; P 0.05) compared to the physiological heart rate (5.67% p 4.37, P 0.05). At reduced heart rate, mean percentage area of LGE correlated highly with the mean percentage of the histologic inflammation area (r = 0.80 to r = 0.87, P 0.05). LGE was mainly located in the anterior and lateral left ventricular wall and septum with a midwall to subepicardial accentuation. Conclusion: EAM in the rat model is verifiable by clinical MR magnet and due to high correlations between CMR examination results and histopathological findings, the current animal model can provide the opportunity for further radiologic fundamental research. LGE in the anterior and lateral left ventricular wall with midwall to subepicardial accentuation seems to be a typical pattern in EAM. Heart rate appears to influence signal intensity of LGE in EAM. B-252 14:09 Cardiac MRI in AlstrГ¶m syndrome F. Corbetti1, P. Maffei1, S. Romano1, C. Lacognata1, G. Milan1, J. Marshall2; 1 Padova/IT, 2Bar Harbor, ME/US ([email protected]) Purpose: To present the first findings of cardiac MRI in AlstrГ¶m syndrome, a rare genetic disorder characterized by metabolic disturbances, deafness, blindness and fibrotic infiltration of multiple organs including heart, possibly resulting in dilated cardiomiopathy. Methods and Materials: 5 patients aged 26-41 yrs with AlstrГ¶m syndrome and ALMS1 gene mutations (Chr. 2p13) underwent cardiac MRI using short axis SSFP sequences and dedicated software for functional evaluation, black blood T1and T2 sequences for tissue evaluation, and late enhancement sequences (LE) after gadobutrol (0.2 mmol/kg) to detect fibrosis. Inversion time (TI) 5’, 10’ and 15’ after contrast injection was assessed using a TI scout sequence and compared with values obtained in 10 healthy subjects by T test. Results: Left ventricular function was normal in 1 case, mildly depressed in 3 (EF 48-55%) due to slight diffuse hypokinesia, and severely depressed in 1 (EF 23%) due to septal akynesia and severe hypokynesia of other segments. Black blood T1 Scientific Sessions B-253 14:18 Prognostic value of cardiac magnetic resonance (CMR) morpho-functional findings in young subject with clinical suspicion of arrhythmogenic right ventricular dysplasia (ARVD) A. Esposito, F. De Cobelli, E. Mancini, E. Belloni, S. Ravelli, R. Mellone, V. Fisichella, A. Del Maschio; Milan/IT ([email protected]) Purpose: ARVD is an important cause of sudden cardiac death (SCD) among young athletes. CMR is the gold standard to identify the morpho-functional findings which are included in diagnostic criteria (McKenna criteria; MKc), whereas the CMR’s potential prognostic role has been poorly investigated. The aim of the present study was to explore the prognostic value of CMR findings in young patients referred for a suspicion of ARVD. Methods and Materials: A total of 38 patients (27 males, 11 females; age = 25.2 p 6.8 years) with a clinical ARVD suspicion underwent CMR at 1.5 T. Intracardiac electrophysiological study (EPS) was also performed in all patients. The occurrence of major arrhythmic events (MAE) was monitored during a follow-up of 16.4 p 5.3 months after the CMR. Results: Only 1/38 patients had sufficient MKc for ARVD diagnosis. The 38 patients were separated into three groups according to the morpho-functional criteria identified at CMR: G1) absence of MKc; G2) up to 2 minor-MKc; G3) major-MKc or more than 2 minor-MKc at CMR. The three groups did not differ for anthropometrics and clinical features excepting age (G1 = 24 p 7;G2 = 25 p 7 G3 = 32 p 3 years; P 0.05). None of the 25 subjects included in G1 had MAE during follow-up. Two of 9 (22%) of G2 and 1/4 (25%) of G3 experienced MAE during follow-up. Conclusion: All subjects without CMR diagnostic criteria for ARVD remained free from MAE during the follow-up suggesting that a negative CMR could be considered a favourable prognostic factor. The two patients of G2 who experienced MAE during follow-up did not have sufficient criteria for ARVD diagnosis; this result suggests the opportunity to submit to EPS all ARVD-suspected patients with an incompletely negative CMR for MKc. B-254 14:27 Cardiac and mediastinal involvement in Erdheim-Chester disease: CT and MR findings D.L. Touitou, A.-L. Brun, C. Beigelman-Aubry, J. Haroche, P. Cluzel, P.A. Grenier; Paris/FR ([email protected]) Purpose: To retrospectively review the cardiac and mediastinal findings at computed tomography and magnetic resonance imaging in a large series of 32 patients with biopsy-proven Erdheim-Chester disease. Methods and Materials: Two chest radiologists reviewed in consensus thoracic CT scans (n=32) and cardiac MDCT (n=25) and MR (n=18) scans of thirty-two patients with Erdheim-Chester disease (21 men and 11 women; mean age 53.8 years, range 19-75). Results: Circumferential periaortic infiltration was observed in 25 patients (78%). Extension of periaortic infiltration affected supraaortic trunks in 21 patients (65%), coronary arteries in 17 patients (51.5%), intercostal arteries in 8 patients (25%). Perivascular coronary infiltration was always located around the right coronary artery, less frequently around the left coronary artery (n=9). Nine patients (28%) presented with abnormal infiltration of the right atrial wall and 5 patients (16%) with severe narrowing of the right atrial lumen and superior vena cava stenosis. Pericardial thickening and/or effusion was observed in 20 cases (62%). Infiltration of the posterior mediastinum was seen in 17 patients (53%) with contiguous thickening of the subpleural space and pleural effusion and/or thickening predominant in the right hemithorax in 15 patients. Conclusion: Erdheim-Chester disease has a wide spectrum of cardiac and mediastinal manifestations. Infiltration of the right atrio-ventricular sulcus around the right coronary artery, pseudo-tumoral infiltration of the right atrium wall associated with periaortic and retrocrural space infiltrates are highly suggestive of the diagnosis. B-255 14:36 Quantitative MRI in the detection of cardiac iron in patients with thalassemia J. Yamamura, R. Engelhardt, R. Grosse, J. Graessner, R. Fischer, G.E. Janka, G. Adam; Hamburg/DE ([email protected]) Purpose: Quantitative MRI methods (e.g., GRE-R2*) have been developed for the measurement of cardiac iron. In a cross-sectional study in patients with betathalassemia (TM) and sickle-cell disease (SCD), we aimed to assess patients with elevated R2* at risk of developing problems from cardiac iron toxicity. Methods and Materials: In the short axis view, R2* was analyzed from signal intensities by exponential fitting. Breathhold retrospective ECG-gating was used on a 1.5 T imager (SymphonyВ®, Siemens, Erlangen), acquiring data from nine heartbeats with eight echo-times between 1.9 and 21.5 ms in end-diastole (TR = 223 ms, flip angle = 20В°). The left ventricular function was assessed from 6 mm short and long axis of cine series spanning the entire cardiac cycle (25 phases). Liver iron concentration (LIC) was measured by SQUID biomagnetic liver susceptometry in 14 patients getting blood transfusions (TM: n = 11, SCD: n = 3, age: 17-43 y) and 3 normal subjects. Results: In patients with TM, a median relaxation rate of R2* = 76 s-1 (range: 22-340 s-1) was determined with 7/11 patients having R2* values above the widely accepted normal threshold of 50 s-1. Patients with SCD did not differ from normal (range: 27-38 s-1). A significant correlation between R2* and LIC was found (Spearman rank RS = 0.56, P = 0.01). In one patient, a high R2* of 222 p 18 s-1 indicated a potential risk for developing CHF, although the LIC was at an optimum value of 938 Вµg/g wet weight and the LVEF of 58% was still normal (49%, before1 y). Conclusion: Elevated cardiac iron levels as indicated by R2* were found in all of our thalassemia patients older than 21 y, although severe levels (R2* 100 s-1) were only found in patients older than 29 y. B-256 14:45 Assessment of cardiac iron and right ventricular function by GRE-MRI in patients with thalassemia and sickle cell disease J. Yamamura1, R. Engelhardt1, R. Grosse1, J. Graessner1, G. Kurio2, T. Mir1, R. Fischer1, G.E. Janka1, G. Adam1; 1Hamburg/DE, 2Oakland, CA/US ([email protected]) Purpose: The aim was to evaluate the RV function (RVEF) and the cardiac iron in patients with thalassaemia major/intermedia (TM/TI) and sickle-cell disease (SCD). Methods and Materials: In 9 splenectomized patients (4TM, 4TI, 1SCD: 24-43 y), 5 SCD patients (19-24 y) and 16 TM patients (11-32 y), the R2* was determined from short-axis slices. Breathhold retrospective ECG gating was used on a 1.5 T imager (SymphonyВ®, Siemens) acquiring data from nine heartbeats with eight echo times between 1.9 and 21.5 ms in end diastole (TR = 223 ms, flip angle = 20В°). LV function was assessed from 6 mm short and long axis slices (25 phases). RVEF was estimated from LV stroke volume and RV end-diastolic volume. The left interventricular curvature ratio (LVCR) was derived by delineating the circular midsystolic LV shapes between RV junction points. RVEF was related to RV systolic pressure (RVSP) and N-terminal pro-brain natriuretic peptide (NT-proBNP). Results: Cardiac-R2* above the normal threshold of 50 s-1 were determined in 5/10 splenectomized patients and in 6/16 TM patients. Patients with SCD did not differ from the normal (range: 29-33 s-1). The LVCR was determined between 0.6 and 0.9. Only in splenectomized patients, there was a decreased LVCR of 30 mmHg indicating pulmonary hypertension. LVEF and RVEF were normal. Only in two patients with extreme NT-proBNP levels ( 1,000), a reduced RVEF of 46 % at still normal LVEF was detected. Conclusion: Although normal LV function was found in nearly all of our thalassemia and sickle cell patients, we detected signs of pulmonary hypertension with the interventricular curvature ratio, especially in older splenectomized patients independent of their cardiac iron load. B-257 14:54 Magnetic resonance (MR) evaluation of myocardial iron storage and left ventricle ejection fraction (LVEF) in patients with thalassemia major (TM) C. Ottonello1, F. Secchi1, G.D.E. Papini1, A. Giardino1, C. Turchetti1, A. Ciancio2, A. Fragasso2, A. Aliprandi1, F. Sardanelli1; 1Milan/IT, 2Matera/IT ([email protected]) Purpose: To evaluate myocardial iron storage and LVEF in patients with TM. Methods and Materials: Thirty patients with TM (age 30p7 years) treated with longterm desferoxamine (n=20), deferiprone (n=4), or both (n=6) underwent 1.5-T MR imaging with dual-echo T2*-weighted 4-chambers long-axis fast field echo sequence (TR/TE1/TE2=12/4.6/9.2 ms). For each patient, we measured signal intensity (SI) A B C D E F G H S195 Friday and T2 images were unremarkable. On LE images, 2/3 pts with mildly impaired EF showed slight midwall and/or transmural LE involving 1 and 2 segments; diffuse midwall and transmural LE was found in the case with severe ventricular dysfunction. TI values at 5’, 10’, 15’ were lower than in control group (133.7p7.5 vs 185.5p21.9 p 0.000; 164p13 vs 212.4p17.3 p 0.000; 180.2p14.3 vs 227.3p18.9 p 0.001) even in patients without visual evidence of LE. Conclusion: Cardiac MRI allows accurate evaluation of function and detection of fibrosis in AlstrГ¶m syndrome. Reduced TI values might indicate microscopic fibrosis in absence of visual LE. Scientific Sessions for three ROI placed in basal, middle, and apical interventricular septum. Myocardial T2* was calculated using the following formula: T2* =-$TE/ln[SI (TE2)/SI (TE1)]. A mean myocardial T2* 20 ms was considered as an iron storage. LVEF was obtained from standard short-axis cine true-FISP sequences. Serum ferritin concentration was measured and the mean value of the previous 12 months was considered. Spearman correlation and Mann-Whitney test were used. Results: Myocardial T2* was 26.0p10.1 ms; LVEF was 56p7%; serum ferritin concentration ranged within 321-4.910 ng/ml (median 869 ng/ml). Out of 30 patients, 10 had myocardial T2* 20 ms. Mean serum ferritin concentration was 2.458p1.660 ng/ ml for the 10 patients with myocardial T2* 20 ms and 1.259p930 ng/ml for the 20 patients with myocardial T2* r20 ms (p=0.082). The Spearman coefficient between T2* and serum ferritin concentration was -0.329 (p=0.076), that between T2* and LVEF -0.005 (p=0.979), that between serum ferritin concentration and LVEF -0.453 (p=0.012). Conclusion: Despite long-term iron-chelating therapy, about one-third of TM patients showed abnormal myocardial T2* values. While there was no correlation between T2* and LVEF, a significant correlation was found between serum ferritin concentration and LVEF and a borderline correlation between T2* and SFC. B-258 15:03 Effect of enzyme replace therapy on patients with Anderson-Fabry disease: A three years follow-up study assessed by MRI M. Imbriaco, A. Pisani, B. Cianciaruso, E. Capuano, M. Fusari, G. Avitabile, M. Marmo, M. Salvatore; Naples/IT ([email protected]) Purpose: Anderson-Fabry (AF) is a multisystem X-linked disorder of lysosomal metabolism associated with left ventricular (LV) hypertrophy. This study evaluated the effects of enzyme replace therapy (ERT) on LV function and myocardial signal intensity, assessed by MRI, in patients with AF, after 3-years of ERT. Methods and Materials: 13 patients with AF (10 men/3 women, mean age: 33p10 years) underwent MRI at baseline (study 1) and after 3-years of ERT (study 2) with recombinant a-galactosidase-A. MR studies were performed using a breath-holding T2 weighted multi-echo TSE sequence with four different echo times, to obtain images of the 4-chamber horizontal long-axis plane for myocardial T2 relaxation time (MT2RT) measurements. 3D balanced turbo field echo sequences were obtained for evaluation of LV mass and ejection fraction (LVEF). Results: No differences were observed in LVEF between study 1 and 2 (65p3 vs 66p5% p: n.s). A significant decrease in LV mass, was observed between study 1 (189p58 g) and 2 (152p45 g), (p 0.001). There was a significant reduction in LV wall thickness between study 1 and 2 (16p4 vs 14p4 mm, p 0.001). A significant reduction in MT2RT was observed between study 1 and 2 (p 0.001) in all myocardial regions (inter-ventricular septum 79p6 vs 64p9 msec, apex 78p10 vs 63p10 msec and lateral wall 80p8 vs 64p16 msec). Conclusion: In patients with AF, there is a significant regression in cardiac hypertrophy, with a reduction in MT2RT after 3-years of ERT. Long term therapy with A-galactosidase-A is effective for treatment of these patients, significantly improving overall cardiac performance. B-259 15:12 Myocardial hemosiderosis: Comparison of three methods for the construction of myocardial T2* color parametric maps using data obtained directly from a research PACS system T.G. Maris1, K. Karolemeas2, K. Pagonidis1, N. Papanikolaou1, A.H. Karantanas1; 1 Iraklion/GR, 2Athens/GR ([email protected]) Purpose: To compare three methods for the calculation of myocardial T2* values assessed by means of quantitative MRI (T2*-qMRI) utilizing image data obtained directly by a research PACS system. Methods and Materials: Myocardial T2* values were calculated in 40 thalassemic patients (mean age: 27 p 3.3 yrs, median age: 25.7 yrs) and 20 normal subjects on a 1.5 T MRI system using an ECG-gated breathhold short axis 2D single-slice multi echo (12 echoes) gradient echo (MEGRE) sequence with parameters: TR/TE1/ TE12/FA 180/2.4/28.9 ms/25o in end diastolic phase. T2* color image maps were reconstructed using : (a) a commercially available, (b) a conventional linear and (c) a weighted linear regression fitting algorithm utilizing post-proceassing tools of a research PACS system. Liver iron concentration (LIC) was estimated non-invasively using Yves Gandon's (Rennes University, France) methodology. Myocardial T2* values were correlated with LIC and serum ferritin concentration (SFC) using all methods. The methods were compared using Bland Altman (BA) tests. Results: Differences of myocardial mean T2* values between patients and normal subjects were considered to be extremely significant (t = 22.25, P 0.0001) with all the methods. Myocardial T2* values were not correlated with LIC or SFC for all methods. Method (a) showed increased variability when compared with methods S196 A B C D E F G F H (b): [mean:3.7 ms, 95% range: 6.5 ms] and (c): [mean: 2.8 ms, 95% range: 9.2 ms] using the BA test. Method (c) showed the best mean %CV (7.6%) as compared to methods (b) (12%) and (a) (19%). Conclusion: T2*, as assessed using color T2* parametric maps and weighted regression analysis methods, seems to be a valuable means for an easy and precise evaluation of myocardial hemosiderosis. B-260 15:21 Fatty foci in the myocardium of patients with tuberous sclerosis complex: A unique finding on CT M.E.A.P. Adriaensen1, C. Schaefer-Prokop2, D.A.C. Duyndam2, B.A. Zonnenberg1, M. Prokop1; 1Utrecht/NL, 2Amsterdam/NL ([email protected]) Purpose: On abdominal CT performed for monitoring renal angiomyolipomas in patients with tuberous sclerosis complex (TSC), we had frequently noticed focal areas of fat within the myocardium. This case-control study examines frequency and morphologic characteristics of focal fatty foci in the myocardium of TSC-patients. Methods and Materials: We included 55 TSC-patients with a mean age of 34 years (range 12 to 73 years; 22 males) in whom a CT was available that included at least the basal portions of the heart. Fifty-five age- and sex-matched controls without TSC were selected from our CT-database. We reviewed all scans for the presence of wellcircumscribed foci of pure fat density in the depicted portions of the myocardium. We used descriptive statistics and a chi-square-test for case-control comparison. Results: CT demonstrated foci of fat density within the myocardium in 35/55 TSC-patients (64%). Foci were located in the interventricular septum, left ventricle wall, right ventricle wall, and papillary muscles. Size varied between 3x1 mm and 62x31 mm. Multiple lesions were seen in 19 patients. In the control group only one lesion with fat density was found (1/55; 2%; p 0.001). Its characteristics differed from those of TSC patients: linear shape and subendocardial location in the left ventricular wall were suggestive of prior myocardial infarction. Conclusion: Despite incomplete depiction of the heart with CT, the majority of TSCpatients demonstrated well-circumscribed foci of pure fat density in the myocardium that were not present in age-and sex-matched controls. This suggests that such fatty foci may be a new characteristic of TSC. Scientific Sessions A B C D E F G H S197 Saturday Saturday, March 7 Scientific Sessions room A 2nd level room B 2nd level room C 2nd level room E1 entr. level room E2 entr. level room F1 entr. level room F2 entr. level room G/H lower level room I lower level room K lower level 07:00 07:00 07:30 07:30 08:00 08:00 08:30 CC 517 Cardiac Imaging Cardiac CT and MRI: :KDWZLOOWKH IXWXUHEULQJ" (p. 32) 09:00 09:30 CC 516 Spinal Imaging and Intervention Spinal infections and LQГЂDPPDWLRQV (p. 32) NH 5 New Horizons Session Cell imaging: &DQWKH radiologist see WKHFHOO" (p. 33) CC 518 Breast: From Basics to Advanced Imaging Breast lesions at PDPPRJUDSK\ and US: How to FKDUDFWHULVH" (p. 34) EВі 520a Foundation Course: Imaging of the Urinary Tract %H\RQGWKH kidneys (p. 34) EВі 520b Interactive Teaching Session Imaging in common clinical SUREOHPV /RZEDFN pain (p. 35) 08:30 SF 5a Special Focus Session 3HULSKHUDO nerves (p. 35) EF 1 EFOMP Workshop Advances LQDYDLODEOH tools (p. 36) WS 521 Image-Guided Breast Biopsy: How to do it Hands-on :RUNVKRS Lecture HS 1 Hospital Management Symposium Finance 09:30 10:00 10:00 10:30 EM 1 ESR meets Switzerland SS 610 Switzerland Musculoskeletal Top of Hip and muscle Europe: 3.0 (p. 200) 7HVODDQGWKH 0DWWHUKRUQ (p. 41) 11:00 11:30 SS 601a Abdominal Viscera Liver and ELOHGXFWV Oncology (p. 202) 10:30 EВі 620 Foundation SS 609a Course: Interventional Imaging of Radiology the Urinary Venous Tract and renal Intervention interventions and (p. 204) transplantation (p. 42) SS 602 Breast Intervention (p. 206) EF 2 EFOMP Workshop Advances in clinical applications (p. 43) SS 603a Cardiac 5LJKW KHDUWDQG pulmonary arteries (p. 208) HS 2 Hospital Management Symposium IT 11:00 11:30 12:00 12:00 Honorary Lecture 1 (p. 43) 12:30 13:00 SY 3 Guerbet Satellite Symposium (p. 523) 2nd Workstation Face-Off Session SY 4 Toshiba Satellite Symposium (p. 524) HS 3 Hospital Management Symposium Management SY 5 GE Healthcare Satellite Symposium (p. 524) 13:30 12:30 13:00 13:30 14:00 14:00 SS 710 Musculoskeletal 6KRXOGHU8SSHU H[WUHPLW\ (p. 219) 14:30 15:00 SS 701 Abdominal Viscera Pancreas (p. 221) SY 7 GE Healthcare Satellite Symposium (p. 524) SY 8 Bayer Schering Pharma Satellite Symposium (p. 525) EВі 720 Interactive Teaching Session Breast cancer: Diagnosis, staging and follow-up (p. 43) SS 709a Interventional Radiology (PEROLVDWLRQV DQGELRSVLHV (p. 223) SY 9 Siemens Healthcare Satellite Symposium (p. 526) SS 708 Head and Neck Developmental, autoimmune and parotid disorders (p. 225) SS 713 Physics in Radiology Structural and functional imaging (p. 227) SS 712 Pediatric &DUGLRWKRUDFLF (p. 229) 14:30 15:00 15:30 15:30 16:00 16:30 18:00 registration (326ВЊVFLHQWLВїFH[KLELWLRQ 17:30 WHFKQLFDOH[KLELWLRQ 17:00 18:30 09:00 CC 817 Cardiac Imaging Myocardial perfusion and YLDELOLW\ (p. 44) CC 816 Spinal Imaging and Intervention 6WDEOHRU XQVWDEOHVSLQH injury? (p. 44) EM 2 ESR meets Emergency Physicians Time is life (p. 45) 16:00 RC 807 Genitourinary Imaging of WKHDGQH[DO masses (p. 47) RC 802 Breast Breast MRI: Lesion FKDUDFWHULVDWLRQ (p. 48) RC 811 Neuro Stroke (p. 49) RC 815 Vascular Imaging of FULWLFDOOLPE LVFKHPLD (p. 49) TF 1 RTF Radiology Trainees Forum +LJKOLJKWHG Lectures (p. 50) 16:30 17:00 17:30 18:00 18:30 19:00 S198 RC 810 Musculoskeletal Osteoporosis (p. 46) EВі 820 Interactive Teaching Session Imaging in common clinical SUREOHPV Acute DEGRPHQ (p. 47) 19:00 A B C D E F G F H Scientific Sessions room L/M 1st level room N/O 1st level room P 1st level room Q 2nd level room R 1st level room U 2nd level room W 2nd level room X 1st level room Y 2nd level room Z 2nd level 07:00 07:00 07:30 07:30 08:00 08:00 08:30 09:00 09:30 08:30 SF 5b Special Focus Session 5KHXPDWRLG DUWKULWLV (p. 37) MC 519 Advances in CT and MRI in Major Trauma Body trauma (p. 38) RC 504 Chest Critical issues in pulmonary HPEROLVPDQG pulmonary K\SHUWHQVLRQ (p. 39) RC 501 Abdominal and RC 507 Genitourinary Gastrointestinal :KDWWRGRZLWK Benign focal liver OHVLRQV:KLFK DOOWKHVHVPDOO modality for renal masses? ZKDW" (p. 40) (p. 40) WS 524 Functional Imaging of Tumors: How to do it Hands-on :RUNVKRS Lecture WS 523 Cardiac CT PostProcessing and Analysis 09:00 09:30 10:00 10:30 11:00 10:30 SS 611 Neuro Tumors (p. 210) 11:30 SS 601b GI Tract (VRSKDJXV 6WRPDFK Motility and cancer (p. 212) SY 2 Bracco Satellite Symposium (p. 523) SS 609b Interventional Radiology Carotid and intracranial interventions (p. 214) SS 603b Cardiac Myocardial perfusion (p. 216) WS 621 Image-Guided Breast Biopsy: How to do it WS 624 Functional Imaging of Tumors: How to do it Hands-on :RUNVKRS Lecture WS 622 Experience Vascular Procedures Using Simulators 11:00 11:30 12:00 12:00 12:30 12:30 SY 6 Hitachi Satellite Symposium (p. 524) 13:00 13:00 13:30 13:30 14:00 14:00 14:30 15:00 SS 715 Vascular 7KHUDS\ evaluation (p. 231) SS 711 Neuro Stroke (p. 234) SS 704 Chest Airway imaging and functional data (p. 236) SS 709b Interventional Radiology Liver: TACE (p. 238) SS 703 Cardiac WS 721 ,PDJLQJYLDELOLW\ Image-Guided and valve Breast Biopsy: disease How to do it (p. 240) WS 722 Experience Vascular Procedures Using Simulators WS 724 Functional Imaging of Tumors: How to do it ESOR (The European School of Radiology) 15:00 15:30 15:30 16:00 16:00 16:30 17:00 14:30 SF 8 Special RC 808 Focus Head and Session Neck 5DGLRIUHTXHQF\ ,QIUDK\RLGQHFN DEODWLRQEH\RQG (p. 52) WKHOLYHU (p. 51) RC 804 Chest Diagnostic PLPLFVLQFKHVW diseases (p. 52) RC 809 Interventional Radiology 8WHULQHВїEURLG HPEROLVDWLRQ (p. 53) RC 801 Abdominal and Gastrointestinal $EGRPLQDO05, 3URWRFROVWKDW work (p. 54) 16:30 17:00 17:30 17:30 18:00 18:00 18:30 18:30 19:00 19:00 A B C D E F G H S199 Saturday 10:00 Scientific Sessions 10:30 - 12:00 Room B SS 610 Hip and muscle Moderators: E. Belloch; Alzira/ES C. Czerny; Vienna/AT 10:30 Location of femoral head asphericity by magnet resonance arthography: Do normal radiographs exclude femoro-acetabular impingement? M. Dudda, T.C. Mamisch, C.E. Albers, K.A. Siebenrock, S. Werlen, M. Beck; Berne/CH ([email protected]) Purpose: Asphericity of the femoral head neck junction is one cause for femoroacetabular impingement (FAI) of the hip and is often underestimated on conventional radiographs. The aim was to analyze the appearance of the morphology of the proximal femur, comparing the radial sequences of magnet resonance arthrography (MRA) and standard x-rays. Methods and Materials: A total of 55 hips of 148 patients, who underwent a surgical dislocation of the hip were analysed. The alpha angle and height of asphericity were measured in 14 positions using radial sequences of MRA. MRI protocol with radial proton density weighted (PDW) sequences (TR 2000, TE 15, 260 x 260 mm field of view, 266 x 512 matrix, 4 mm section thickness, 16 slices, 4 min 43 sec) were orientated along the axis of the femoral neck. Separation into four groups was done with respect to the appearance of an aspheric head neck junction on ap pelvic and lateral cross table radiographs: group.i. : no radiographic signs of FAI; group II: only on the cross table view; group III: only on the ap view; group IV: with signs of FAI in both ap and cross table views. Results: In all groups, an increased alpha angle and asphericity were found in the anterosuperior area of the head neck junction. In group III, additionally there was an asphericity inferior. Conclusion: Even when conventional radiographs were normal, an increased alpha angle indicating asphericity was present. Without use of radial sequences in MRA, FAI would be missed in symptomatic patients. Normal radiographs did not exclude asphericities of the proximal femur. B-262 10:39 MR imaging in the diagnosis of labral and cartilage hip lesions in 43 patients with femoroacetabular impingement syndrome and surgical correlation G.E. Zamora, G. Delgado, E. Bosch; Santiago/CL Purpose: Classically, MR arthrography has been used to diagnose labral and chondral pathology in patients with clinical diagnosis of femoroacetabular impingement syndrome. The purpose of our study is to assess the effectiveness of MR imaging in the evaluation of acetabular labrum and articular cartilage in comparison with arthroscopy findings. Methods and Materials: We reviewed, retrospectively, the original imaging reports of MRI studies performed between June 2005 and March of 2008 on 1.5 T MR system, in 43 patients referred with the clinical diagnosis of femoroacetabular impingement, and who subsequently underwent hip arthroscopy. The study group included 15 female and 28 male patients of a mean age of 37 years old, with 23 right and 20 left hips. In order to evaluate labral and chondral lesions, a comparison was made between the imaging findings in the original report and the corresponding arthroscopy protocols. Results: The MR imaging for labral lesions shows a sensibility of 81%, a specificity of 92%, a PPV of 93%, a NPV of 79%, and accuracy of 90%. The MR imaging for chondral lesions grade II and higher shows a sensibility of 59%, a specificity of 94%, a PPV of 94% and a NPV of 54%, accuracy of 94%. Conclusion: MR imaging is an adequate method for the evaluation of labral lesions in patients with clinical diagnosis of femoroacetabular impingement. On the other hand, MR imaging is not a reliable method for the evaluation of chondral lesions in these group of patients. S200 A B C 10:48 Cartilage degeneration in femoroacetabular impingement: Utility of standard diagnostic versus delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) for early diagnosis B. Bittersohl1, S. Steppacher1, T. Haamberg1, Y.-j. Kim2, S. Werlen1, M. Beck1, K. Siebenrock1, T.C. Mamisch1; 1Berne/CH, 2Boston, MA/US ([email protected]) Musculoskeletal B-261 B-263 D E F G F H Purpose: To study the T1 patterns for different types of femoroacetabular impingement (FAI) by utilizing delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and subsequent 3D T1 mapping. We used standard radiography for comparative analysis. Methods and Materials: dGEMRIC was obtained from ten asymptomatic youngadult volunteers and 26 symptomatic FAI patients. MRI included the routine hip protocol and a dual-flip angle 3D gradient echo (GRE) sequence utilizing inline T1 measurement. Cartilage was morphologically classified from the radial images based on the extent of degeneration as: no degeneration, degeneration extent 0.75 cm, degeneration extent 0.75 cm, or total loss and radial T1 findings were evaluated and correlated. Results: The T1 distribution reflected the FAI damage pattern and was in keeping with earlier reports. All FAI cases revealed remarkably lower T1 mean values in comparison to asymptomatic volunteers. In cam-FAI, there was a significant drop of T1 in the anterior to superior location. In pincer-FAI, there was no drop in the T1 values at a specific region but a circumferential decrease was noted. Further, T1 values revealed cartilage degeneration that was not singularly restricted to the acetabular rim as noted with morphological MRI. High inter-observer (intra-observer) reliability was noted for T1 assessment 0.89 (0.95). Conclusion: We conclude that there exists a pattern of zonal T1 variation that seems to be unique for a sub-group of FAI lesions. The dual-flip angle GRE approach to perform 3D T1 mapping demonstrates a reproducible method for further studies of dGEMRIC and T1 in the hip joint. B-264 10:57 Sports-related alterations of the hip joint and correlation to typical findings in femuro-acetabular impingement: MR findings in 50 elite Karate fighters I. Kress, K. Siebenrock, S. Werlen, T.C. Mamisch; Berne/CH ([email protected]) Purpose: The aim of the study is to examine the morphologic changes of the hip joint in karate fighters by MRI and investigate the influence of karate training for developmental OA. Methods and Materials: A total of 97 hips in 50 karate fighters were examined at 3 T MRI using axial T1-weighted 3D GRE, PD-weighted TSE fat-sat coronal and sagittal (TR 2650, TE 21, FoV 140, 384 x 384 matrix, 3 mm slice thickness) and intermediate-weighted TSE (TR 1850, TE 15, FoV 140, 512 x 512, 4 mm slice thickness). Clinical examination included impingement test and range of motion. On MRI, the shape of the femoral head and acetabulum, morphology of the labrum and cartilage integrity were graded by two observers. Results: In 42 hips (43.3%), the internal rotation was decreased. The mean alpha angle was increased to 64.3 degrees with a strong correlation to age at the start of training. The labrum was normal in 16 hips (16.5%), degenerated in 48 hips (49.5%) and torn in 33 hips (34%). The cartilage was normal in 14 hips (15%), degenerated in 78 (78%) hips and full thickness defects were present in 6 hips (7%). There was a strong correlation with years of training and start of training for labrum and cartilage abnormalities. Conclusion: A high incidence of clinical and MR alterations of the hip was observed. A decreased femoral head neck offset, typical for femoroacetabular impingement, could be assessed, which correlated with the start of karate training. This indicates a developmental component for FAI and OA of the hip joint. B-265 11:06 Obturator externus bursa: Prevalence of communication with the hip joint and associated intra-articular findings in 110 consecutive hip MR arthrograms A. Kassarjian1, J.T. Bencardino2, E. Llopis3, R.B. Schwartz4; 1Majadahonda/ES, 2 New York, NY/US, 3Alzira/ES, 4Brookline, MA/US ([email protected]) Purpose: To demonstrate the prevalence of communication between the hip joint and the obturator externus bursa at hip MR arthrography. Methods and Materials: Following institutional review board approval, 110 hip MR arthrograms were retrospectively reviewed by 2 musculoskeletal radiologists. The presence or absence of communication between the hip joint and the obturator externus bursa was recorded. Communication between the hip joint and the obturator externus bursa was defined as gadolinium entering the obturator externus Scientific Sessions bursa. The status of the acetabular labrum, articular cartilage, and presence or absence of hip plicae were recorded. Results: 110 hip arthrograms in 108 subjects were independently reviewed by 2 musculoskeletal radiologists. Discrepancies were resolved by consensus. The obturator externus bursa was seen to communicate with the hip joint in 7 of 110 hip MR arthrograms. Of these, 3 were men and 4 were women. The age range was 16-54 years old with a mean age of 33 years. All seven patients had labral tears. Five of the seven had mild degenerative changes including cartilage thinning/defects and subchondral marrow changes. In all seven patients, labral plicae, ligamentous plicae, and femoral neck plicae were visible. Conclusion: The obturator externus bursa can be seen to communicate with the hip joint in 6% of hip MR arthrograms. Associated intra-articular lesions are common. B-266 11:15 Purpose: To study magnetic resonance (MR) perfusion and diffusion characteristics of bone marrow in patients with transient bone marrow edema (BME), avascular necrosis (AVN), and subchondral insufficiency fractures (SIF) of the proximal femur. Methods and Materials: 26 patients with painful hip and BME pattern of the proximal femur on standard MR imaging were examined using line-scan diffusionweighted EPI/HASTE and dynamic gadolinium-enhanced FLASH sequences (1.5 T). Apparent diffusion coefficients (ADCs) and enhancement ratios (ERs) were calculated for different regions of the proximal femur. Regional distribution and differences in ADC and ER values over time were evaluated. Individual diagnoses were confirmed by clinical and radiological follow-up. Results: 12 Patients presented with transient BME, 10 with AVN and 4 with SIF of the femoral head. Patients with transient BME showed significantly (p 0.05) higher ADC values (1.1p0.5) than patients with AVN (0.5p0.3) or SIF (0.6p0.2). In addition, ERs and underlying perfusion patterns of the epiphysis and metaphysis showed significant differences between patients with AVN and transient BME. Conclusion: The preliminary results of this study indicate that MR perfusion and diffusion imaging may be useful additional tools to differentiate patients with transient BME and AVN as well as SIF. These complementary imaging techniques may also add information to the understanding of the pathophysiology of diseases associated with bone marrow edema. B-267 11:24 Optimisation of metal artefact reduction sequences (MARS) for MR imaging of total hip prostheses A.P. Toms, C. Smith, P.N. Malcolm; Norwich/UK ([email protected]) Purpose: Metal artefact reduction sequences (MARS) reduce susceptibility artefact from metal prostheses using high bandwidths and matrix sizes but this comes at a cost of loss of SNR and increased acquisition time. The aim of the study is to describe the relative contribution of matrix size and bandwidth to artefact reduction in order to define optimal sequence parameters. Methods and Materials: A phantom was created using the femoral component of a Charnley THR set in solid fat. A mid-coronal T1W (TE 12 ms, TR 400 ms) image through the prosthesis was acquired with increasing bandwidths (150, 300, 454, 592 and 781 MHz) and for each bandwidth, images were acquired with a matrix of 128, 256, 384, 512, 640 and 768 pixels square. Signal loss from the prosthesis and susceptibility artefact was segmented using an automated tool. Results: In total, 80% reduction in artefact was achieved for all bandwidths at a matrix of 384x384. The greatest reduction in artefact occurs with a matrix of 768x768 and bandwidth of 150 MHz. However, for matrices of 512x512 or larger, the increasing bandwidth caused a paradoxical increase in artefact. Increasing bandwidth produced a relative fall in SNR between 49% and 56% but in practice image quality was still satisfactory. Conclusion: When planning MARS protocols using matrices of 512x512 or greater are counterproductive. The optimal combination of spatial resolution and artefact reduction can be achieved with a matrix of 384x384 and the highest achievable receiver bandwidth. 11:33 Predictive value of MRI in rectus femoris strain injuries R. Rodrigo, J. Santisteban, R. Ortega, F. Angulo, M. Rodriguez, M. EreГ±o; Bilbao/ES ([email protected]) Purpose: To investigate the relationship between MRI findings of rectus femoris strain injuries and their recovery interval (RI) in professional soccer players. Methods and Materials: A prospective study was carried out on 36 strains produced by indirect mechanisms. MRI was performed using a 1.5 GE device with a surface coil within 1-7 days of the injury. The following MRI findings have been correlated with clinical outcome and routine statistical analysis was performed: anatomical location (direct tendon, indirect tendon, myoconnective or combined injuries), site (proximal or middle third), size (cross-sectional and length), presence of perifascial fluid or absence and T1 findings (thicker muscle, focal or diffuse hypo /hyperintensity, blurring of myotendinous unit). Results: The mean age was 22.1 years; mean recovery period was 28.3 days. Regarding the anatomical structure affected, 72% had perifascial fluid: 30% myoconnective, 27.8% indirect tendon, 36.1% direct tendon and 19.4% combined injuries with no statistically significant difference in RI. Regarding the site of injury, proximal lesions had longer RI (30.9 vs 24.2 days). Regarding the size of injury, cross-sectional area injury greater than 50% had longer RI (36.6days). Lesions with fascial fluid took longer RI (30.5 vs 22.7 days). Lesions seen on T1 had longer RI (39.6 days; P = 0.0012). Conclusion: MRI findings are helpful to predict the prognosis of rectus femoris injuries. The association of three of the following four findings, proximal lesion, injury seen on T1WI, cross-section greater than 50% and presence of perifascial fluid, are poor outcome features with longer RI of 38.29 vs 25.9 days (P = 0.006). B-269 11:42 Diffusion tensor MRI-based dynamic study of acute injury and frozen recovery in rat skeletal muscle F. Wang, S. Pan, Q. Li, Y. Sun, Q. Guo; Shenyang/CN ([email protected]) Purpose: To explore the application of DTI in the model of acute injury and frozen recovery in rat skeletal muscle. Methods and Materials: A total of 20 Wistar rats (female, weighing 323-451 g, average 386 g) were divided into four groups (each of 5). Acute trauma models were made with pressured injury machine (leg muscle, 500 N, 100 mm/min). Among them, 5 rats in the control group were not give any interference and 15 rats in the experimental group were given ice compress at 10, 20 and 30 minutes. MRI was performed with a 3.0 T MRI scanner (Philips Intera Achieva) before and immediately after the injury and after 24, 48 and 72 hours. The DTI parameters were: TR/TE = 943/65 ms, b = 600 s/mm2, six diffusion probing gradient directions, 5 mm thickness. Fiber tracking tool (PRIDE version 4.1.V3) was used to calculate the ADC and FA values. Results: (1) ADC and FA values were 0.68 p 0.03 x 10-3 mm2/s and 0.46 p 0.05 x 10-3 and had no statistical differences in each group before the injury. (2) ADC values were increased to 0.77 p 0.02 x 10-3 and 0.71 p 0.03 x 10-3 mm2/s, and FA values were decreased to 0.36 p 0.02 x 10-3 and 0.39 p 0.02 x 10-3 for controls immediately after the injury and after 24 hours. (3)ADC values were respectively 0.71 p 0.04 x 10-3 and 0.70 p 0.02 x 10-3.0.71p0.02x10-3 mm2/s, and FA values were respectively 0.41 p 0.03 x 10-3, 0.42 p 0.02 x 10-3 and 0.42 p 0.04 x 10-3 at the 10, 20 and 30 minutes group immediately after injury. ADC values were respectively 0.69 p 0.03 x 10-3, 0.68 p 0.04 x 10-3 and 0.69 p 0.02 x 10-3 mm2/s, and FA values were respectively 0.42 p 0.03 x 10-3, 0.42 p 0.02 x 10-3 and 0.42 p 0.02 x 10-3 in the three experimental groups 24 hours after injury. Compared to the control group, the range of change in the ADC and FA values were reduced in the experimental groups. (4) The ADC and FA values had no significant difference between the control and experimental group at 48 and 72 hours after injury. Conclusion: DT-MRI can non-invasively reflect the muscle acute injury and recovery process. Frozen recovery had better efficacy to limit muscle edema due to injury. B-270 11:51 MR perfusion imaging correlated with vessel density in a rabbit model of hind-limb muscle tissue ischemia W. Zhang, D. Wang, M. Men; Beijing/CN ([email protected]) Purpose: To evaluate the acute alteration and chronic recovery in muscle perfusion after excision of femoral artery using multiphase ce-MRI and correlate them with new vessels density. Methods and Materials: Acute ischemia was induced in right hind-limbs of 14 NewZealand white rabbits by complete excision of femoral artery. The acute alteration and the chronic recovery of muscle reperfusion were examined, respectively, prior to A B C D E F G H S201 Saturday Can magnetic resonance perfusion and diffusion imaging help to differentiate transient bone marrow edema, avascular necrosis and subchondral insufficiency fractures of the femoral head? Preliminary results D. MГјller, J.S. Bauer, F. Walter, H. Rechl, E.J. Rummeny, K. WГ¶rtler; Munich/DE ([email protected]) B-268 Scientific Sessions and 0.5 hr, 1 day, 3, 7, 14, 21, 28, 42, 56, 70 days after excision of femoral artery on a 1.5 T MR. A 5 mm-thick axial section through the middle of both femurs was imaged using a T1weighted 2D-FLASH sequence. A bolus of Gd-DTPA was administered then 265 image acquisitions were obtained. The percent MR signal enhancement of the ROI (2.0 cm2) in bilateral limbs muscle was plotted and the parameters were analyzed and compared with vessel density of specimens HE-stained. Results: After artery excision, a significant reduction in affected muscle perfusion was observed at 0.5 hr. compared to that before excision: ArriveTime (122p11.58 s VS 14.2p0.663 s), SI changing rates (at 10 s, 0.0055p0.002%/s VS 0.7600p0.091%/s, at 30 s, 0.0172p0.003%/s VS 0.4776p0.079%/s), Peak Height (2.676p0.598% VS 23.54p3.206%). Perfusion recovered very slowly during the first 7 days post-excision and faster perfusion recovery was observed from 14 to 28 days, following by a slower recovery till to 70 days corresponding to the increasing of vessel density (2.0, 1.0, 3.0, 6.0, 8.0, 9.0, 11.0, 15.0, 21.0, 18.0, respectively). Conclusion: Multiphase ce-MR imaging could assess time-dependent changes of muscle perfusion, which correlated with angiogenesis in a rabbit model of hindlimb ischemia. 10:30 - 12:00 Room C Abdominal Viscera (Solid Organs) SS 601a Liver and bile ducts: Oncology Moderators: B.I. Choi; Seoul/KR S. Terraz; Geneva/CH B-271 10:30 Radiofrequency ablation for recurrent hepatocellular carcinoma in postoperative patients: Prognostic factors analysis Y. Lin, Y.-Y. Chiou, Y.-H. Chou, H.-K. Wang, J.-H. Chiang, C.-Y. Chang, H.-K. Wang; Taipei/TW ([email protected]) Purpose: The aim of this study was to determine the prognostic factors which will affect the disease-free survival of the post-operative patients after percutaneous ultrasound-guided radio frequency ablation for recurrent HCC. Methods and Materials: From August 2002 to May 2008, 82 (64 men, 18 women, mean age: 64.27 years) patients had previous lobectomy or segmentectomy of the liver due to HCC and suffered from tumor recurrence. Total 82 patients received initial percutaneous RFA for recurrent HCC and were evaluated the cumulative diseasefree survival of overall intrahepatic recurrence (mean follow-up period: 14.3 p 12.4 months). Nine host, tumoral and therapeutic factors were reviewed in correlation with disease-free survival: age, gender, hepatitis marker, ablation needle, location, size, ablation time, post-ablation temperature and pre-ablation AFP level. Results: The cumulative disease-free survival rate of overall recurrence was 63.5% at one year, 24.1% at two years and 14.4% at three years. Univariate analysis showed that tumor size, hepatitis marker and pre-ablation AFP level were significant factors related to poor survival (P 0.05). Multivariate analysis identified that factors related to poor survival were pre-ablation AFP level and tumor location (segment 7, 8) with a hazard ratio of 3.7 and 2.7. Conclusion: Pre-ablation AFP level and tumor location are significant factors related to poor survival. In patients with recurrent HCC close to liver dome and elevated AFP level, multimodality treatment or other treatments should be considered. The result would have clinical significance for appropriate management of patients scheduled for RFA who suffered from recurrent HCC after previous surgery. B-272 10:39 Prediction of viable tumor in HCC treated with radiofrequency: Evaluation of a semi-quantitative index at contrast-enhanced US (CEUS) P. Cabassa, E. Gavazzi, E. Orlando, R. Monesi, M. Morone, R. Maroldi; Brescia/IT ([email protected]) Purpose: To evaluate the efficacy of a semi-quantitative index in monitoring the therapeutic response of hepatocellular carcinoma to radiofrequency ablation (RF) with CEUS Methods and Materials: One month after RF, 23 consecutive HCC were evaluated. US-guided RF was performed with expandable needles. CEUS was performed with second-generation contrast media (SonoVue, 2.4 ml) with dedicated software (Contrast coherent imaging). One significant frame (bitmap format) of the portal phase was chosen for each treated lesion and analysed by software (AdobePhotoshop 7.0). Two circular manually defined regions of interest (ROI) for each S202 A B C D E F G F H image were drawn encompassing the treated lesion and the adjacent normal liver parenchyma. Sonography videotape intensity (VI) was measured in gray-scale levels (0-255) through histogram analysis for each ROI. Background intensity was set at the same level for each image. A semi-quantitative index (VItumor-VIliver/ VIliver) was calculated. Index values were compared with 1-month MDCT (standard of reference). Statistical analysis was performed to depict the cut off value for tumor persistence. Results: Median index value was -0.71 (95%CI : 0.07) for necrotic lesions and -0.38 (95%CI : 0.10) for viable lesions. The value of -0.6 showed the best performance to discriminate the viable tumor from the necrosis (sensibility 100%, PPV 100%). Conclusion: We quantified the treatment outcome of HCC 1 month after RF ablation by a simple reproducible index. From the preliminary data, the cut off of -0.6 seems to be predictive of therapeutic success. B-273 10:48 Safety margin assessment after radiofrequency ablation using the fusion images of the pre- and post-RFA 3D CT scans K. Kim1, J. Lee1, E. Klotz2, S. Kim1, S. Kim1, J. Han1, B. Choi1; 1Seoul/KR, 2 Forchheim/DE Purpose: To evaluate a new technique, the fusion images of registrated pre- and post-RFA CT scans, for safety margin assessment after radiofrequency-ablation (RFA). Methods and Materials: In 31 patients with hepatocellular carcinomas, who were treated with RFA and underwent available pre-RFA and post-RFA CT scans, the fusion images of pre- and post-RFA CTs were created using prototype software (HepaCare: Siemens), which uses non-rigid registration with world-coordinate algorithm. Two radiologists (reader 1 with experience in 500 RFA cases, reader 2 with experience in 50 RFA cases) independently reviewed pre-RFA and post-RFA CT images in two separate sessions in blinded manner; first session without fusion images, and second session with fusion images. Degree of safety margin was rated and compared with the reference value determined by other expert in RFA with all information. Interobserver agreement, interpretation time, and image quality of fusion images were evaluated. Results: In experienced reader, good correlation between reader’s safety margin assessment and the reference values was observed in both of first and second interpretation sessions (r=0.916 and 0.868, respectively). In less experienced reader, better correlation was obtained in second session than that in first session (r=0.863 and 0.692, respectively). With the fusion images, interobserver agreement for safety margin between the two readers increased (kappa; 0.526 in first session, 0.819 in second session). Thirty patients (96.8%) showed good image quality of fusion image. With the fusion images, interpretation time was shortened by about 1.5 minutes (p 0.01). Conclusion: Fusion images of pre- and post-RFA CT is a feasible and useful technique for safety margin assessment after RFA. B-274 10:57 Immuno-stimulating effect in thermal ablation of liver metastases from colorectal cancer T.J. Vogl1, M.G. Mack1, T.T. Wissniowski2, J. HГ¤nsler2, N. Naguib1; 1 Frankfurt a. Main/DE, 2Erlangen/DE ([email protected]) Purpose: To assess whether laser-induced thermotherapy (LITT) induces a specific cytotoxic T-cell response in liver metastases of colorectal cancer and to define the induced immune response. Methods and Materials: The prospective study was approved by the institutional review board and informed consent was obtained from all patients. Eleven patients with liver metastases of colorectal cancer were treated with MR-guided LITT. Blood samples were taken before and after LITT. Test antigens were autologous liver and tumor lysate obtained from each patient by biopsy. Peripheral T-cell activation was assessed by interferon-gamma (IFNg) secretion assay and flow cytometry. T-cells were stained for CD3+, CD4+, and CD8+ and IFNg to detect cytotoxic T-cells. The ratio of IFNg-positive and IFNg-negative T-cells was determined as stimulation index (SI). To assess cytolytic activity, T-cells were co-incubated with human colorectal cancer cells (CaCo), and release of cytosolic adenylate kinase was measured by luciferase assay. Results: Before LITT, SI was 12.73 (p4.83) for CD3+, 4.36 (p3.32) for CD4+ and 3.64 (p1.77) for CD8+ T-cells against autologous tumor tissue. Four weeks after LITT, SI increased to 92.09 (p12.04) for CD3+ (P 0.001), 42.82 (p16.68) for CD4+ (P 0.001) and 47.54 (p15.68) for CD8+ T-cells against autologous tumor tissue. No increased SI was observed with normal liver tissue at all times. Before LITT, cytolytic activity against the respective cancer cells was low with RLU = 1493 (p1954.68), Scientific Sessions and after LITT it increased to RLU = 7260 (p3929.76 [P 0.001]). Conclusion: Patients with liver metastases of colorectal cancer show tumorspecific cytotoxic T-cell stimulation with significantly increased tumor-specific cytolytic activity of CD3+, CD4+ and CD8+ T-cells after LITT, thus defining a new field of immune therapy. B-275 11:06 Multidetector-row computed tomography perfusion imaging in hepatocellular carcinoma after transcatheter arterial chemoembolization L. Yang1, X.-P. Zhou2, X.-M. Zhang1; 1Nanchong/CN, 2Chengdu/CN ([email protected]) B-276 11:15 Predicting response of colorectal hepatic metastasis: Value of pretreatment rim attenuation T. Nakagawa, Y. Ryu, M. Nakadate, I. Umehara; Chiba/JP ([email protected]) Purpose: The purpose of this study was to determine whether the pretreatment rim attenuations of hepatic metastatic lesions from colorectal cancer were predictive of response to chemotherapy. Methods and Materials: This retrospective study reviewed 42 patients with hepatic colorectal metastases who underwent CT (16 or 64 detectors) before FOLFOX4 or FOLIFIRI regimen. CT of upper abdomen was obtained 75-80 sec after iv injection of iodinated contrast media. An adjusted injection rate was performed for the constant injection time of 50 sec. On CT images, ROIs corresponding to the lesions (ROIin) and the lesions plus rim (ROIout) were drawn. Rim attenuations were calculated by the following formula: HUrim = (Aout Г— HUout - Ain Г— HUin)/(Aout - Ain), where A is area (mmВІ) and HU is attenuation. The average value of HUrim from 3 slices of lesions was used for the evaluation. Results: Pretreatment rim attenuations of responders (n = 13) and non-responders (n = 29) were 104.9 p 15.7 HU and 90.0 p 9.7 HU, respectively, and showed significant difference between them (p = 0.0060; Mann-Whitney’s U test). Progressionfree survivals of patients with low rim attenuation ( 90 HU) and the others were 4.6 p 2.9 months (n = 13) and 9.1 p 5.6 months (n = 23), respectively, and also showed significant difference (p = 0.0194). Conclusion: High and low pretreatment rim attenuations of colorectal liver metastases were predictors for good response and short progression-free survival, respectively. The pretreatment rim attenuations of colorectal hepatic metastases were predictive of response. B-277 11:24 Added value of metabolic information in the search for primary cancer and presence of any malignancy using FDG-PET/CT P. Fencl1, J. Machac2, G. Kacl3, J. Weichet1, O. Belohlavek1; 1Prague/CZ, 2 New York, NY/US, 3Schlieren/CH ([email protected]) Purpose: To assess the additional diagnostic value of FDG-PET/CT in comparison to contrast-enhanced CT (CECT) in the search for primary cancer and for the presence of malignancy in patients with cancer of unknown primary (CUP) B-278 11:33 Diagnostic value of image fusion of MRI and FDG-PET in patients with suspected primary liver and pancreatic malignancies C.S. Reiner, O.F. Donati, T.F. Hany, B. Marincek, D. Weishaupt; Zurich/CH Purpose: To investigate the value of image fusion of magnetic resonance imaging (MRI) and positron emission tomography (PET) on the diagnostic confidence for the assessment of lesion dignity and presence of regional lymph node metastases in patients with suspected primary liver or pancreatic malignancies. Methods and Materials: 26 patients (13 women, 13 men; mean age 54.9 years) with suspected primary liver or pancreatic malignancies who underwent contrastenhanced MRI and (18)F-fluordeoxyglucose-PET were included. Manual, rigid image registration with six degrees of freedom and fusion of MRI and PET-data sets was performed. Two independent readers separately assessed MR images alone and in combination with fused PET/MRI images. Images were analyzed using a five-point-confidence scale for dignity of lesions and the presence of regional lymph node metastases. Results were correlated to histopathology. The data were analyzed using receiver operating characteristic (ROC) curves. Results: 15 patients had a primary liver malignancy, 8 patients had pancreatic cancer, and 3 patients benign lesions. In determining lesion dignity, the mean areas under the ROC curves were 0.95 for MRI and 1.0 for PET/MRI for reader 1 (p 0.05), and 0.88 for MRI and 1.0 for PET/MRI for reader 2 (p 0.05). The Az-values for detection of regional lymph node metastases were low, except for the subgroup of liver malignancies (MRI: 0.79/0.66, PET/MRI: 0.80/0.98 for reader 1/2). Conclusion: Fused PET/MRI images may increase the confidence for dignity assessment in patients with suspected primary liver and pancreatic malignancies. The technique may also be beneficial for detection of possible lymph node metastases. B-279 11:42 Classification of response to treatment in liver metastatic disease: Comparison between volume and unidimensional measurements on MRI M. Mantatzis, S. Kakolyris, K. Amarantidis, G. Daskalogiannakis, I. Mokali, A. Karagiannakis, P. Prassopoulos; Alexandroupolis/GR ([email protected]) Purpose: The response to treatment of liver metastases on imaging is currently based on lesions’ diameter measurements, proposed by RECIST (Response Evaluation Criteria in Solid Tumors). The aim of the study was to compare RECIST criteria with volumetric measurements in the evaluation of response to treatment of patients, with liver metastases, undergoing chemotherapy. Methods and Materials: A total of 44 patients with colorectal cancer and newly diagnosed liver metastases were included in this prospective study. Patients underwent three MRI examinations, at treatment initiation, during chemotherapy and immediately post-treatment. Measurements based on RECIST guidelines and volume calculations were performed on the “target” lesions (TL) and patients were stratified in four response categories. Results: The two methods were in agreement in 64/77 of patients and 253/301 of individual lesions classification in response categories (“good” agreement, Cohen Kappa = 0.735 and 0.741, respectively). In 16.88% of the comparisons the two methods stratified patients to different response categories. Of the TLs, 27.6% did not follow the response category of the patient where lesions were located (“moderate” agreement, Cohen kappa = 0.542), reflecting the presence of various A B C D E F G H S203 Saturday Purpose: To study the value of multidetector-row computed tomography (MDCT) perfusion imaging in hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). Methods and Materials: Twenty-four consecutive patients with HCC who received TACE were prospectively evaluated with MDCT perfusion imaging within one week before and one month after TACE. The CT perfusion parameters such as hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP), total liver perfusion (TLP) and hepatic arterial perfusion index (HAPI) were calculated using the slope method, respectively. The correlation between the values of CT perfusion parameters in tumors before TACE and the levels of iodized oil deposition in HCC after TACE was performed by using spearman correlation analysis, and the difference of the CT perfusion parameter values in HCC before and after TACE was performed with t-statistic. The P value cutoff for statistical significance was set at 0.05. Results: The values of HAP and TLP in tumors before TACE showed significant positive correlation with the levels of iodized oil deposition in tumors after TACE (P 0.05, respectively), the values of HPP and HAPI were not related to the levels of iodized oil deposition (P 0.05, respectively), and the average values of HAP, TLP and HAPI in tumors decreased significantly one month after TACE compared with those before TACE (P 0.05, respectively), the value of HPP grossly unchanged after TACE compared with that before TACE (P 0.05). Conclusion: MDCT perfusion imaging is a useful modality for evaluating prognosis of patients with HCC after TACE. syndrome. Methods and Materials: CECT data of FDG-PET/CT in 72 patients were investigated by Biograph Duo. LSO due to CUP were randomly split into three subgroups of 36 patients each and blindly reevaluated by three experienced radiologists. Sensitivity (SE), specificity (SP) and accuracy (ACC) was defined for FDG-PET/CT as well as for each CECT reader, based on gold standard (histology and/or clinical follow-up). McNemarВґs and Fisher’s tests were used for comparisons between groups; inter-reader agreement was expressed by kappa. Results: For diagnosing primary, SE was 63% for FDG-PET/CT and 44, 45 and 38% for CECT readers; SP was 80% for FDG-PET/CT and 72, 35 and 79% for CECT readers; ACC was 76% for FDG-PET/CT and 66, 38 and 70% for CECT readers. There were significant differences between FDG-PET/CT and one CECT reader in SP and ACC. In diagnosing the presence of neoplasm, SE was 93% for FDG-PET/CT and 86, 92 and 88% for CECT readers; SP was 84% for FDG-PET/ CT and 43, 38 and 81% for CECT readers; ACC was 86% for FDG-PET/CT and 59, 57 and 84% for CECT readers. There were significant differences between FDG-PET/CT and two CECT readers in SP and ACC. Inter-reader agreement in ACC was weak (kappa 0.00-0.37). Conclusion: In this group of patients, FDG-PET/CT was more specific and accurate than CECT. CECT was significantly reader-dependent. Scientific Sessions malignant cell clones. The actual volume of TLs differs from the calculated volume of a sphere with the same diameter by 98%. Wilcoxon z = -5.03, P b 0.001 suggesting that the "sphere model" may be inappropriate. Conclusion: Differences between RECIST criteria and volumetric measurements question the accuracy of assessment by linear measurements. Volumetric techniques may overcome certain disadvantages of the currently used unidimensional measurements. to flow measurements. This promising new method needs clinical validation. B-280 Purpose: The purpose of the paper is to describe the imaging features of intraductal papillary neoplasms of the bile ducts based on the pathologic findings. Methods and Materials: Imaging findings of 53 cases with intraductal papillary neoplasm of the bile ducts were retrospectively reviewed by two radiologists and the results were correlated with pathologic findings. Based on the pathologic features, one pathologist classified the shape of the intraductal neoplasms as mass forming, cast-like growing, cyst forming (with or without intracystic mass) and superficially spreading. On imaging, the shape of the mass was categorized as mass forming when there was apparent mass in the bile duct with or without hepatic parenchymal invasion; cast-like growing type when the mass filled the dilated bile duct in a relatively long segment; cyst forming type when the involved ducts showed cystically dilated bile duct, which resembled aneurysm with or without intracystic nodules or masses; superficial spreading type when lobar or segmental bile ducts were dilated markedly without apparent mass. Results: Of the 53 cases of intraductal papillary neoplasms, there were 16 cases of mass-forming, 17 cases of cast-like growing, seven cases of cyst forming, nine cases of superficially spreading and four cases of the combined type. Conclusion: Intraductal papillary neoplasm of the bile ducts can be classified into intraductal mass forming, cast-like growing, aneurysmal dilatation of the bile ducts with or without intracystic mass or disproportionately severe dilatation of the lobar or segmental intrahepatic bile ducts without apparent masses. Purpose: To analyze prospectively the efficacy of interventions in acute dysfunctional hemodialysis fistulas, respecting interventionalist, time of day, and lesion type. Methods and Materials: Institutional Review Board approval was obtained. From 2005 to 2007, all the (n = 280) patients with acute dysfunctional hemodialysis fistula were immediately referred to intervention suite, irrespective of time of day. In n = 241 cases, intervention was performed. Following procedural success rates were calculated: total, by interventionalist (experienced, A-C; less experienced, D-I), by time of day (routine staff, 07:00a.m.-04:00p.m.;emergency staff, 04:00p.m.07:00a.m)., and by lesion type (stenosis; sclerotic occlusion; thrombotic occlusion; mixed stenosis/occlusion). Two-sided level of significance was set at p 0.025 for interventionalist and lesion type, and one-sided level of significance was set at p 0.05 for time of day. Results: Total success rate was 62%(149/241). Success rates by interventionalists were 76%(32/42) for A (p = 0.068), 72%(26/36) for B (p = 0.083), 64%(21/33) for C (p = 0.600), 54%(15/28) for D (p = 0.787), 52%(12/23) for E (p = 0.770), 64%(9/14) for F (p = 0.449), 50%(6/12) for G (p = 0.722), and 70%(7/10) each for H and I (p = 0.193), respectively. Success rates by time of day were 68%(93/136) for routine staff, and 53%(56/105) for emergency staff (p = 0.047). Success rates by lesion type were 82%(94/104) for stenosis (p 0.01), 39%(13/33) for sclerotic occlusion (p = 0.083), 18%(6/33) for thrombotic occlusion (p 0.01), and 59%(36/61) for mixed stenosis/occlusion (p = 0.484), respectively. Conclusion: 1) Success rates by interventionalist did not reach level of significance. 2) With routine staff available, interventions in acute dysfunctional hemodialysis fistulas are more likely to be successful. 3) Stenosis is very likely to be treated successfully, while thrombotic occlusion is not. 10:30 - 12:00 B-284 11:51 Morphologic classification of intraductal papillary neoplasm of the bile ducts: Radiologic-pathologic correlation J. Lim, H. Lim, D. Choi, K.-T. Jang, J. Lee; Seoul/KR ([email protected]) Room E1 SS 609a Venous and renal interventions Moderators: I. BattyГЎny; PГ©cs/HU T. Lupattelli; Milan/IT 10:39 Detection of hemodialysis vascular access stenosis by intravascular pulse pressure analysis: An in-vitro study R.N. Planken1, K. van Canneyt2, S. Eloot2, P. Verdonck2; 1Amsterdam/NL, 2Gent/BE ([email protected]) Purpose: Vascular access (VA) thrombosis, due to significant stenoses ( 50%), is the main cause of VA failure in hemodialysis patients. Flow measurements enable detection of stenoses 70% and not 50%. Flow measurements regularly fail to prevent thrombosis. The purpose of the study was to test a new technique for detection of significant stenoses ( 50%). Methods and Materials: A pulsatile in-vitro model of a radio-cephalic arteriovenous fistula with silicone tubes, a reservoir and a pump was created. A 15G needle was introduced at 5 and 10 cm downstream of the anastomosis. Intravascular pulse pressure amplitude (systolic minus diastolic pressure = PP) was measured in the arterial inflow and at the arterial needle. PP ratios were calculated (PP-needle/ PP-inflow*100%). A 50% stenosis was introduced in the arterial inflow, between needles and in the venous outflow, successively. Measurements were repeated at different heart rates (60-90 beats/min) and different flows (500-1,300 ml/min). ANOVA analysis and post-hoc tests were used to evaluate the relation between the PP ratio and the presence of a stenosis in different conditions. Results: PP ratios were 20.26 p 4.55% (no stenosis), 7.69 p 2.08% (arterial inflow stenosis), 36.20 p 2.12% (between needles stenosis) and 32.38 p 2.17% (venous outflow stenosis). Stenoses can be located upstream and downstream of the needle (P 0.001). Between needles stenoses and venous outflow stenoses could also be distinguished (P 0.001). Conclusion: Pulse pressure analysis enables detection of 50% stenosis independent of heart rate and flow volume. It also enables stenoses localization, in contrast S204 A B C D 10:48 Interventions in acute dysfunctional hemodialysis fistulas: Prospective analysis of efficacy in 241 cases P.J. Schaefer, N. Charalambous, F.K.W. Schaefer, M. Heller, T. Jahnke; Kiel/DE ([email protected]) 10:57 Retrieval of a new optional vena cava filter S. Pieri1, P. Agresti1, L. Pancione2, D. LaganГ 3, G. Carrafiello1; 1Rome/IT, 2Torino/IT, 3 Varese/IT ([email protected]) Interventional Radiology B-282 B-283 E F G F H Purpose: The role of vena cava filter has changed over the last decades. Optional vena cava filters, removable after a long permanence, is the novelty that overcomes the limits of temporary and permanent filters. We report our observations and problems connected with the retrieval of a new filter. Methods and Materials: Between 1999 and 2005, 276 filters were implanted. Retrieval was attempted in 78, with transjugular approach and directly observation under fluoroscopy of the capture of the head of the filter by the legs of the retrieval system. Results: Technical success was 93%. In the 6 cases of failure, the main reason was the angle of the filter with the vena cava. Difficulties were found in the 72 procedures completed: in 10 patients (12.8%) there was a difficulty in covering the gripper filter with the retrieval sheat after the initial capture (non alignment of the filter). 6 cases required the use of other devices in order to facilitate better positioning in axis with the retrieval system. Median stay was 173 days. Conclusion: The optional vena cava filter with long permanence is a useful surgical aid. Despite problems connected with a physiological learning curve, in our experience their retrieval proved feasible in the majority of cases, without complications. B-285 11:06 Incidence, outcome and prognostic factors of post TIPS liver dysfunction in patients with cirrhosis A. Luca1, A. D’Antoni1, R. Miraglia1, G. Vizzini1, B. Gridelli1, J. Bosch2; 1 Palermo/IT, 2Barcelona/ES ([email protected]) Purpose: To evaluate the short-term (within 6 weeks) effects of elective TIPS on liver function in patients with cirrhosis, define incidence and outcome of post TIPS liver dysfunction (PTLD) and identify prognostic factors of PTLD. Methods and Materials: We analyzed data from 192 consecutive cirrhotic patients who underwent elective TIPS. PTLD was defined as presence of at least two of following criteria: bilirubin 3 mg/dl (if 3 mg/dl prior TIPS) or increase 100% (if 3 mg/dl prior TIPS), decrease of prothrombin time 30 points%, decrease of albumin 10 g/dl, encephalopathy II stage. Scientific Sessions Results: TIPS was placed for refractory ascites and/or hydrothorax (52%) and recurrent variceal bleeding (48%). Twenty-six (13.5%) patients developed PTLD. Three patients died within 6 weeks, 3 patients died within 6 months, 5 patients underwent liver transplantation from 1.5 to 6 months after TIPS (all them were on waiting list for LT before TIPS), and in 15 patients PTLD reverted over the follow-up. Patients who developed PTLD had a lower survival at 6-weeks (87 vs. 100%, p 0.05) and 6-months (72 vs. 96%, p 0.05) compared with patients without PTLD. Multivariate analysis revealed that higher serum bilirubin (p=0.0001) and younger age (p 0.004) were independently associated with the risk of PTLD. Conclusion: PTLD is not uncommon in patients with cirrhosis who underwent elective TIPS, and although in more than 50% of cases it is transitory in the other cases is cause of death or requires liver transplantation. Serum bilirubin and younger age are independent prognostic factors of PTLD. B-286 11:15 Purpose: To define the role, efficacy and feasibility of TIPS in non-cirrhotic patients with symptomatic portal cavernoma refractory to standard therapy. Methods and Materials: From March 1998 to November 2007, 24 non-cirrhotic symptomatic patients with portal cavernomatosis (symptoms: ascites, intestinal ischeamia, variceal bleeding, and varices at high risk of bleeding) were admitted to our hospital. Fifteen patients (62.5%) responded satisfactorily to medical and/or endoscopic therapy. Nine patients (37.5%) did not responded completely to standard therapy and were evaluated for a TIPS. One patient was excluded because of bilateral occlusion of the internal jugular vein. TIPS was performed in 8 pts (33.3%) only with a trans-jugular access using a thin needle (21G) TIPS-set for the direct search of the portal axis. Portal vein was crossed in 7 patients (87.5%) and a Viatorr stent (WL Gore) was successfully implanted. Early shunt thrombosis was observed after 2 days in one patient with complete occlusion the splenic and superior mesenteric vein and in which the stent was positioned in a large collateral vein arising from the portal vein. Results: After a mean follow-up of 17 p 10.5 months a primary patency rate was 71% (5/7 patients) with a secondary patency rate of 83.3% (6/7). One patient died of hepatocarcinoma with patent shunt 6 months after the procedure. Conclusion: TIPS can be considered safe and effective in non-cirrhotic patients with symptomatic portal cavernoma refractory to standard therapy or in need of anticoagulation. B-287 11:24 Percutaneous portal vein embolisation for extended hepatic resection: Volume gain and achievement of operability in 85 patients A. Koops1, E. Ramcic1, G. Krupski2, G. Adam1; 1Hamburg/DE, 2Reinbek/DE Purpose: Percutaneous portal vein embolisation is an established procedure for the induction of segmental liver hypertrophy in primarily irresectable liver malignancies. The purpose of this study was to assess the increase of the left-lateral segmental volume and the achievement of operability in patients with intended extended right hepatectomy. Methods and Materials: Portal vein embolisation was performed in 85 patients with primarily irresectable liver malignancies. A mixture of histoacyl/lipiodol was placed in the complete course of all accessible portal branches of segments 4-8 by subxiphoidal left-sided (71%) or lateral right-sided (29%) approach. CT was used for volumetry before and every of 3-4 weeks after embolisation until the patients reached the necessary future remnant liver size (prospected remnant weight of at least 0.8% body weight). The clinical definition of operability was determined by this volume gain, but also by tumor development, secondary CT findings, and the general state of health. Results: After a mean interval of 32 days a left-lateral segmental volume gain of 138 ml (59%) was found, with a hypertrophy rate of 4.3 ml/d (2.1%/d). In 52 of 85 patients (61%), complete tumor resection by extended right hepatectomy was successfully performed. Continuous inoperability in 33 patients was caused by tumor progression, new manifestation in the future liver remnant, or new extrahepatic metastases in 56% of these cases; only 9% were due to insufficient volume gain. Conclusion: Portal vein embolisation is a promising preoperative interventional procedure for the induction of segmental liver hypertrophy to achieve operability in initially inoperative patients. 11:33 Role of superselective renal tumors transcatheter embolization before laparoscopic partial nephrectomy: Methods, safety and efficacy G. Vallati, G. Pizzi, L. Carpanese, R. Kajal, M. Crecco; Rome/IT ([email protected]) Purpose: Perioperative bleeding, during laparoscopic nephron-sparing surgery (NSS), is a quite common event. The authors evaluated the effectiveness of selective trans-arterial renal tumors embolization (TAE) before laparoscopic NSS for reducing periprocedural haemorrhagic complications. Methods and Materials: From August 2003 to January 2008, TAE was performed in 80 patients with small, hypervascular, predominantly exophitic, renal tumor. Median tumor size was 3.5 cm; no lesion was found adjacent to the collecting system. TAE was performed through the vessels feeding the tumor and the surrounding parenchyma, in order to obtain a small controlled necrotic area. A total of 78 patients underwent selective TAE with polyvinylalcohol 300-500 Вµm sized particles while in only two, acrylic glue was used. Angiographic absence of further arterial feeders confirmed the procedure efficacy. About 6 hours after TAE, patients underwent a laparoscopic NSS. Mean operative time was measured, as well as mean estimated blood loss and post-operative outcome. Results: No loss of significant viable renal tissue occurred after TAE. Mean operative time of laparoscopic NSS was of 45 minutes and a mean estimated blood loss was of 50 ml. No patient required blood transfusion. Average hospital length stay was 5 days; complications were only reported in three patients. Conclusion: Laparoscopic NSS is recognized as a valid alternative to open surgery. However, the rate limiting step of this technique is to achieve an adequate hemostasis. Pre-operative TAE of kidney tumors seems to be a safe technique that should be used before laparoscopic NSS for effective management of possible perioperative active renal bleeding. B-289 11:42 Percutaneous temporary vessel occlusion for robotic partial nephrectomy with a thermoplastic polymer S. Flacke1, J. Merhige2, A. Moinzadeh1, K.G. Lyall3, J. Wilkie2, C.W. Bakal1, J. Libertino1, J.-M. Vogel2, P. Madras1; 1Burlington, MA/US, 2Woburn, MA/US, 3 Sunnyvale, CA/US ([email protected]) Purpose: To demonstrate the feasibility of reversible vessel embolization using a thermoplastic polymer to provide complete hemostasis for partial robotic nephrectomy. Methods and Materials: After isolation of the left kidney of 7 anaesthetized pigs (50-70 kg) using a daVinci-S-HD system (Intuitive Surgical), a renal angiogram was performed using a 7 F guiding catheter (Veripath, Guidant) placed in the left main renal artery. 5 F C2-catheter (Cook) was inserted into upper or lower pole segmental artery, respectively, followed by embolization using a thermoplastic polymer (LeGoo-XLв„ў, Pluromed). After complete hemostasis of the targeted region, a partial robotic nephrectomy was performed and the kidney subsequently sutured. Residual occlusion was reversed by injecting cold saline through the catheter and reperfusion was documented. Degree and duration of hemostasis was determined. Concentration and preparation of the polymer was modified in five animals. Reproducibility of the technique was confirmed in the remaining experiments. Results: A 20% polymer concentration in a 43% contrast solution (Omnipaque 300) injected at room temperature with a fast manual injection of 0.2 ml followed by a slow injection of up to 0.5 ml under fluoroscopic control occluded a segmental renal artery for more than 45 minutes. The visual appearance of the plug was used to determine the total amount of polymer needed. Hemostasis achieved during surgery was superior to standard clamping techniques. Cold saline dissolved residual polymer. Conclusion: A thermoplastic polymer can be used for reversible occlusion of segmental renal arteries for minimal invasive surgery eliminating warm ischemia of the unaffected kidney and clamping of the renal vessels. B-290 11:51 Ablation of symptomatic cysts using n-butyl cyanoacrylate and iodized oil in autosomal dominant polycyst kidney disease: Long-term results S. Kim1, S. Kim2, J. Cho2, B. Cho2; 1Daegu/KR, 2Seoul/KR ([email protected]) Purpose: To assess the long-term results of cyst ablation with N-butyl cyanoacrylate (NBCA) and iodized oil in autosomal dominant polycystic kidney disease (ADPKD) patients with symptomatic cysts. Methods and Materials: Cyst ablation using mixture of NBCA and iodized oil was performed in 99 cysts of 21 patients with symptoms, such as abdominal distension and pain. The collapse or reaccumulation of ablated cysts after the procedure was assessed during 36 to 90 months follow-up. The treatment effects, including A B C D E F G H S205 Saturday The role of TIPS in non-cirrhotic patients with symptomatic portal cavernoma E. Boatta, F. Fanelli, F. Salvatori, M. Corona, M. Allegritti, P. Rossi, R. Passariello; Rome/IT B-288 Scientific Sessions symptom relief and clinical data such as blood pressure and serum creatinine levels were also assessed together with complication. Results: The 77 of 99 cysts (80%) were totally or partially collapsed. The eight cysts were not collapsed after the procedure. The 14 of ablated cysts were reaccumulated during long-term follow-up. The 17 of 21 patients (76%) were obtained in symptom relief. The four of 12 patients (33%) with hypertension, and the two of six patients (33%) with azotemia were improved. The six of 21 patients (28%) were developed in ESRD at averaging 72 months duration. Significant complication was not encountered. Conclusion: This procedure may be an effective and safe method to ablate the symptomatic cysts in ADPKD. 10:30 - 12:00 Room F2 Breast B-293 SS 602 Moderators: M. Bazzocchi; Udine/IT M.A.A.J. van den Bosch; Utrecht/NL 10:30 Multicenter clinical experience with the new direct frontal 360 degree vacuum assisted large core biopsy device (CoramateВ®) (n=175) R. Schulz-Wendtland1, M. Verjans2, J. Gelin3, L. Rotenberg4, M. Sentis5, G. Verswijfel6, J. Janssens7; 1Erlangen/DE, 2Tienen/BE, 3Goeteborg/SE, 4 Neuilly-sur-Seine/FR, 5Barcelona/ES, 6Gent/BE, 7Diepenbeek/BE ([email protected]) Purpose: Recent innovations in large core biopsies for the human breast led to the development of unique direct frontal and 360 degree vacuum aspiration systems (CoramateВ®). Preclinical and single center clinical trials proved the usefulness of this method. Now the multicenter clinical experience is described. Methods and Materials: Between 10/06 and 3/07, 175 women with a suspect lesion (BI-RADSв„ў 4/5) were eligible for biopsy. Anticoagulant medication was allowed. No prior sedation was given. The lesion was detected by clinical examination, mammography, ultrasound, and/or MRI (BI-RADSв„ў 4/5). The performance of the sampling method, the comfort of the patient, and sample quality was examined. The accuracy of diagnosis is evaluated by comparing the pathology results of the samples and definitive pathology at subsequent surgery. Results: N=175 patients/lesions (BI-RADSв„ў 4/5): N=42 patients/lesions (BIRADSв„ў 4); N=133 patients/lesions (BI-RADSв„ў 5). N=133 patients/lesions (BIRADSв„ў 5), following L-CNB (CoramateВ®): 132 (invasive ductal cancer) (98%), 1 false-negative (DCIS) (2%). An average of 1.73 biopsies per procedure was obtained. The average diameter 4.07 mm with a length of 1.28 cm. All patients had sufficient sample size to make a diagnosis. None of the patients suffered from a serious complication and the procedure was in general extremely well tolerated. Postprocedure esthetic results were excellent. Conclusion: The direct frontal approach with 360В° vacuum aspiration is a new technology (CoramateВ®) that gives excellent diagnostic results without major patient discomfort and with high quality tissue samples. The system is particularly useful in various difficult situations at low costs. B-292 10:39 Percutaneous core needle biopsy of benign papillary lesions of the breast: Incidence and variables associated with atypia and carcinoma at surgical excision V. Londero, A. Linda, C. Zuiani, E. Vianello, A. Furlan, M. Bazzocchi; Udine/IT ([email protected]) Purpose: To retrospectively evaluate the outcome of the cases of benign papillary lesions diagnosed with breast core-needle biopsy. Methods and Materials: Surgical or imaging follow-up (r2 years) was available in 132 women (age range, 33-83 years; mean age: 56 years) with 140 benign papillary lesions diagnosed on sonographically guided core-needle biopsy (128) or stereotactically guided vacuum-assisted biopsy (12). Patient age, clinical presentation, mammographic and sonographic appearance, size, BI-RADS category, biopsy guidance (sonographic or stereotactic) and device (14G core-needle biopsy or 11G vacuum-assisted biopsy) and percutaneous diagnosis (sclerosing papilloma or intraductal/intracystic papilloma or papillomatosis) were retrospectively analysed. The results were compared with the histologic findings at surgery (113) or follow-up S206 A B C D E 10:48 Sonographically guided core needle biopsy of nonpalpable architectural distortions BI-RADS category 4 A-B: Correlation with surgical excisional biopsy and follow-up M. Baeva, J. Oliver Goldaracena, S. Alonso Roca, M. Arguelles Pintos, J. Blanco Cabellos, M. Dominguez Franjo, R. Garcia Perez; Madrid/ES ([email protected]) Intervention B-291 imaging with no change at the 2-year follow-up (27). Statistical analysis was performed using the Fisher's exact test (statistically significant: P-value 0.05). Results: Of 140 benign papillary lesions at core-needle biopsy, upgrade to malignancy was found in 14 (10%) cases and to atypia in 8 (6%) cases. Of the mammographically detected carcinomas and atypical lesions, 55% (6/11) presented as a non-calcified mass, 45% (5/11) as a calcified mass and 0% (0/11) as calcifications (P = 0.022). Patient age, clinical presentation, sonographic appearance, size, BIRADS category, biopsy guidance and device, and percutaneous diagnosis were not significant factors in determining the presence of malignancy or atypia. Conclusion: Clinical, sonographic and biopsy features could not be used reliably to predict the presence of carcinoma or atypia, while mammographic appearance might be helpful. Because of the high prevalence of carcinoma and atypia in these lesions, percutaneous diagnosis of benign papillary lesions is an indication for surgical excision. F G F H Purpose: To show the advantage of sonographically (US) guided core needle biopsy of nonpalpable architectural distortions (NPAD), BI-RADS category 4 A-B, visible on mammography for histological diagnosis and for patient management and decision making. Methods and Materials: A retrospective review of 1,550 lesions sampled with a 14G core needle biopsy performed in our hospital from January 2001 to March 2007 yielded 92 NPAD BI-RADS category 4 A-B. Of all, 67 (on 66 patients, age range 27-92, median 62) were also visible on US, and US-guided core needle biopsy was performed. The lesions size on US ranged from 3 to 17 mm, median 6 mm. The number of obtained specimens ranged from 5 to 11, median 8. A total of 58 patients underwent excisional surgical biopsy and 8 patients were followed mamographically for a mean of 67 months (range 18-72 months). Results: The core needle biopsy results were 49 malignant or high-risk lesions and 18 benign lesions. All of the malignant and high-risk lesions were confirmed as such after surgical excisional biopsy and underwent excision. Correlation with gold standard showed sensitivity 0.93, specificity 1, positive predictive value 1 and negative predictive value 0.86. Mammographic follow-up in the 10 cases that did not undergo excision was performed for 6-96 months, with none showing mammographic or sonographic changes. Conclusion: The US-guided core needle biopsy allows accurate histological diagnosis of NPAD BI-RADS category 4 A-B visible on mammography; therefore, it is a useful guide in making management decisions and allowing a conservative approach for benign lesions. B-294 10:57 MR-guided vacuum-assisted biopsies: Results in 93 patients C. Malhaire, C. El Khoury, A. Tardivon, F. Thibault, A. Athanasiou, P. Petrow, L. Ollivier, S. Neuenschwander; Paris/FR ([email protected]) Purpose: To present our results of MR-guided vacuum-assisted biopsies. Methods and Materials: A total of 97 patients ([58-79 years], mean: 51 years) with 97 isolated MR lesions (negative second-look ultrasound examinations) classified as BI-RADS category 4 or 5 were addressed for vacuum-assisted biopsies. In this population, 29 patients were at high risk (BRCA1 = 16, BRCA2 = 7, familial risk = 6) and 29 had a suspicion of local recurrence of breast cancer. Four procedures were cancelled (undetected lesion = 2, technical problems = 2). Using a 10-gauge vacuum-assisted biopsy probe (Vacora, Bard) on a 1.5 T scanner (Siemens), 93 lesions (focus = 2, mass lesion = 39, non-mass lesion = 52) were sampled, followed by clip placement. In case of benign results, MRI follow-up (28 patients, 30-1,057 days, median 220 days) or mammography (15 patients, 140-1,680 days, median 369 days) was performed. Results: A mean of 20 specimens was obtained per lesion (mean time procedure 75 min, [50-131 min]). At pathology, 47 lesions were benign, 13 at high risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 10) and 33 malignant (ductal carcinoma in situ = 8, invasive cancers = 25). Three false-negative results (3%) were identified and three complications (3%) occurred (one malaise, one skin defect, one infection). Conclusion: MR-guided vacuum-assisted biopsies represent a safe alternative to surgical biopsy for lesions identified at MR imaging only. Scientific Sessions B-295 11:06 MR-guided vacuum-assisted core-needle breast biopsy: Comparison of three vacuum-assisted biopsy devices J.M. Scarth, W. Teh; Harrow/UK ([email protected]) B-296 11:15 Breast MRI for ductal carcinoma in situ: Should we perform it before vacuum-assisted biopsy? M. Lorenzon, N. Martini, C. Zuiani, V. Londero, M. Bazzocchi; Udine/IT ([email protected]) Purpose: Assessing sensitivity of breast MRI performed before and after 11 Gauge Vacuum-Assisted Biopsy (VAB) for the detection of Ductal Carcinoma In Situ (DCIS) in patients with microcalcifications at Mammography. Methods and Materials: We retrospectively reviewed 90 cases with suspicious microcalcifications at Mammography who underwent a 1.5 T MRI before or after VAB, all of them with a final diagnosis of pure DCIS on excision. Cases demonstrating contrast enhancement with morphologic and kinetic features suspicious for malignancy in the corresponding site of microcalcifications were considered as true positive. Our population was divided into 2 groups: Group 1 (G1) was composed of 44 patients who underwent MRI before VAB, Group 2 (G2) was composed of 46 patients who underwent MRI after VAB. The overall sensitivity of MRI for DCIS was assessed. A comparison between MR sensitivity in the two groups was performed and a C2 test was applied to assess a statistically significant difference. Results: Overall sensitivity of MRI for DCIS was 78.8%. MRI sensitivity in G1 was 90.1%, in G2 67.4%. The difference in sensitivity between G1 and G2 was statistically significant (23.7%, p = 0.0133). Conclusion: Due to the scant appearance of certain DCIS, performing breast MRI after VAB could lead to a false negative result. In our practice, MRI performed before VAB exhibits a higher sensitivity for DCIS than after VAB. B-297 11:24 Radial scars at percutaneous breast biopsy: Variables associated with underestimation of malignancy and atypia A. Linda, C. Zuiani, V. Londero, N. Martini, R. Girometti, M. Bazzocchi; Udine/IT ([email protected]) Purpose: To define the rate and variables associated with underestimation of malignancy and atypia when a radial scar (RS) is diagnosed on percutaneous breast biopsy. Methods and Materials: The records of 4,458 patients who underwent imagingguided breast biopsy during an 8-year period were retrospectively reviewed. Surgical or imaging follow-up (r24 months) was available in 75 women with 76 RS diagnosed at stereotactically guided vacuum-assisted biopsy (VAB) or sonographically guided core-needle biopsy (CNB). Biopsy (mammographically guided VAB versus sonographically guided CNB), mammographic and sonographic (detectability, BIRADS category, mammographic and/or sonographic appearance and size) features were reviewed by two readers and correlated with surgical and imaging follow-up that served as the reference standard. The Fischer's exact test was used for the difference in biopsy and imaging features. A P-value 0.05 was considered to be statistically significant. B-298 11:33 Direct MR-galactography in patients with pathological nipple discharge: Add on or substitute for conventional galactography? E. Wenkel, S.A. Schwab, R. Janka, K. Melzer, M. Uder, R. Schulz-Wendtland, W.A. Bautz; Erlangen/DE ([email protected]) Purpose: To evaluate the clinical value of direct magnetic resonance galactography (dMRG) in combination with magnetic resonance mammography (MRM) compared to conventional galactography (KGal) in patients with pathological nipple discharge. Methods and Materials: A total of 25 patients (age range 30-85 years) underwent KGal, dMRG and the standard MRM protocol. The dMRG consisted of a sagittal T1-weighted 3D FLASH (fast low angle shot) sequence (TR 21.0 ms; TE 4.8 ms; matrix 512 x 512; resolution 0.4 x 0.4 x 2 mm, acquisition time: 4 min 42 sec). KGal and dMRG were blinded and analyzed independently in random order by two radiologists. All patients underwent surgery. Results: One patient was excluded from the evaluation because ductal filling was not possible. Histology revealed benign findings in 19/24 women and malignant findings in 5/24 women. There was no difference in the evaluation of the KGal and the dMRG between examiner 1 and 2 regarding duct position and depth of the pathological finding. On comparing KGal and dMRG, in seven patients, both examiners had different results. In six patients, it was caused by a different ductal filling status in KGal and dMRG. In one woman, a different duct was filled in dMRG compared to KGal. In seven patients, surgical procedures were modified due to the results of dMRG and MRM. Conclusion: DMRG, in combination with MRM, allows preoperative localization of the pathological duct and estimation of the extent of the pathology responsible for the nipple discharge. B-299 11:42 Radioactive seed localization of nonpalpable breast lesions L.S.F. Yo, A.W. Daniels-Gooszen, L.E.M. Duijm, Y.E.A. van Riet, G.A.P. Nieuwenhuijzen, M. van Beek, F.H. Jansen; Eindhoven/NL ([email protected]) Purpose: To determine the feasibility of localization of nonpalpable breast lesions by 125-iodine labelled radioactive seeds as an alternative to traditional wire localization. Methods and Materials: We consecutively included 289 women with a malignant, nonpalpable breast lesion at percutaneous core biopsy. Localization was performed with a 4.5 by 0.8 mm titanium seed, labelled with 125-iodine and an activity of 7KBq. At lumpectomy, the surgical oncologist used a Neoprobe 2000 gamma detector, both for the peroperative seed tracing and sentinel node procedure. Results: Respectively, 243 (84.1%), 42 (14.5%) and 4 (1.4%) localizations were performed using ultrasound guidance, stereotactic guidance or a combination of both modalities. For adequate localization, more than one seed was necessary in 43 (14.9%) procedures (multifocal disease: 18; extensive microcalcifications: 9; technical difficulties: 16). Mean localization time was 14 minutes (range, 10-35 minutes) and seeds were located within 1 centimeter from the edge of a lesion in 282 procedures (97.6%). Mean time between localization and surgery was 28 days (range 1-231 days) for the whole study population and 174 days (range, 78-231 days) for those patients (31 women) who underwent neoadjuvant chemotherapy prior to lumpectomy. A total of 50 patients (16.0%) showed irradical tumour resection at lumpectomy, necessitating re-excision or amputation in 29 patients (9.3%). Conclusion: Nonpalpable breast lesions can be localized accurately by 125-iodine labelled radioactive seeds. This technique may have great potential, especially for women undergoing neoadjuvant chemotherapy. In these patients, lumpectomy can be performed even several months after localization by 125-iodine labelled radioactive seeds. A B C D E F G H S207 Saturday Purpose: To review our experience with the Bard Vacora handheld, the Mammotome-MR “open vacuum” and the Suros ATEC “closed vacuum” assisted biopsy systems. Methods and Materials: Retrospective analysis of all MRI vacuum breast biopsies performed between March 2006 and August 2008. Results: A total of 117 biopsies were performed on 108 women, 15 using Vacora, 54 with Mammotome-MR and 48 with the ATEC devices. The average biopsy time with Vacora was 46 minutes (32-83) with an average of 8 cores (1-2), and lesion size of 18 mm (5-90 mm). A total of 47% were malignant with one discordant result subsequently diagnosed as malignant. The average time on the Mammotome-MR was 50 minutes for 1 biopsy and 62 minutes for 2 biopsies (range 35-94), with an average number of 17 cores (4-32) and lesion size of 13.8 mm (3-70). A total of 30% of biopsies had a malignant result with two benign results subsequently diagnosed as malignant. However, more posterior and anterior lesions (n = 14, 26%) were accessed with the Mammotome-M system using вЂ�pillar band post’ guidance. The average biopsy time with ATEC was 39 minutes for 1 biopsy and 53 minutes for 2 biopsies (range 24-62), with an average of 23 cores (8-46) and lesion size of 14.2 mm (4-100). 29% were malignant with no discordant cases. Conclusion: Procedure times were longer with fewer cores using the Mammotome and Vacora; however, Mammotome-MR allowed biopsy of lesions that would not be accessible with the other devices. Results: Surgical excision was performed on 62 (81%) lesions of which 50 (81%) were benign, 7 (11%) atypical and 5 (8%) cancers. The remaining 14 (19%) lesions were unchanged at the 2-year follow-up. Overall percutaneous biopsy underestimation rate of malignancy was 6% (5/76), with 8% (4/52) for sonographically guided CNB and 4% (1/24) for stereotactically guided VAB (P = 0.937). On the comparison of mammographic and sonographic features between benign and malignant or atypical lesions, none of the evaluated findings showed a significant difference between the two groups. Conclusion: Percutaneous breast biopsy is associated with significant sampling error in case of diagnosis of RS. No imaging findings are able to predict which patients require subsequent surgery. For this reason, all patients with RS at CNB or VAB should undergo surgical excision. Scientific Sessions B-300 11:51 B-302 10:39 Do radiologists receive a significant radiation dose localising breast lesions ultrasonically following radio-isotope sentinel lymph node imaging? R.T. Meades, W.E. Svensson, K.S. Nijran, J.W. Frank, V. Gada, G. Ralleigh, N. Barrett; London/UK Right ventricular (RV) delayed enhancement (DE) in patients with idiopathic pulmonary arterial hypertension (IPAH): Final results and prognostic value on cardiac MR (CMR) F. Calabrese, M. Francone, I. Iacucci, M. Mangia, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: Impalpable breast cancers are usually treated with breast preserving excision, guided by wire localisation, and radio-isotope guided axillary sentinel node biopsy. When wire placement follows radio-isotope sentinel node imaging, there is a radiation exposure to the radiologist placing the wire under ultrasound guidance. This risk has not previously been assessed. Methods and Materials: The radiation doses, received by radiologists placing wires under ultrasound control following nuclear medicine sentinel node imaging, were measured for procedures on the day of surgery (20 MBq of isotope) and the day before surgery (40 MBq of isotope). These measurements were compared with calculated theoretical values of dose for each procedure. Results: A total of 12 cases studied showed comparable results between actual dosages and estimated dosages; mean measured dose 1.8 ВµSv (estimated 1.8 ВµSv) for same day surgery cases and 4.8 ВµSv (estimated 3.4 ВµSv) for next day surgery cases. Conclusion: For a worst case scenario this study shows that a radiologist, doing 12 wire localisations immediately following radio-isotope sentinel node imaging on the day before surgery, would receive a radiation dose (0.06 mSv) equivalent to that of one chest X-ray which is equivalent to an additional life time risk of fatal cancer of one in a million. This raises several questions. Are radiologists performing presurgical localisation informed when they are doing it after sentinel node imaging? Are they aware of the relative risk? Is this risk acceptable? Should wire localisation always be performed before radio isotope injection of patients undergoing sentinel lymph node biopsy? Purpose: IPAH is a progressive disease characterized by raised pulmonary vascular resistance, without identifiable cause, which results in diminished right heart function due to increased right ventricular afterload. CMR has emerged as primary non-invasive diagnostic tool for comprehensive assessment of RV function, quantification of myocardial mass and detection of fibrosis. The purpose of this study is to discuss final results and prognostic value of DE in patients with IPAH. Methods and Materials: A total of 57 patients (age range 18-67 years) with clinical diagnosis of IPAH were referred to our Department for CMR evaluation from a reference national center. In all cases right heart hemodynamic parameters were available. An MRI study that included short-axis and horizontal long-axis cine-SSFP imaging and DE acquisitions after contrast-administration (0.1 mmol/kg bodyweight Gd-BOPTA) was acquired in all cases. After data acquisition,ventricular mass index, ejection fraction, end-diastolic, end-systolic and stroke volume index were determined. Presence, location and extent of DE were also analyzed and fibrosis was correlated with RV mass and pulmonary arterial pressure (PAP). Results: Myocardial DE was demonstrated in 43/57 (75%) patients and predominantly confined to the RV insertion points (27/43; 63%) and interventricular septum (16/43; 37%); in 2 cases concomitant LV involvement was found and 7 cases exam was interrupted. Extent of fibrosis correlated positively with RV mass (r = 0.59, p = 0.038) and PAP (r = 0.64, p < 0.01)and inversely with RV ejection fraction (r = -0.69, p < 0.05). Conclusion: DE was observed in most patients. The extent of DE is significantly related to right ventricular systolic disfunction and insertion points are particularly prone to developing fibrosis, which can be used as a prognostic value in patients with IPAH. 10:30 - 12:00 Room I Cardiac B-303 SS 603a Right heart and pulmonary arteries Moderators: A. KГјttner; Erlangen/DE K. Pagonidis; Iraklion/GR B-301 10:30 Non-invasive measurement of elevated mean pulmonary arterial pressure G. Reiter, U. Reiter, G. Kovacs, B. Kainz, K. Schmidt, R. Maier, H. Olschewski, R. RienmГјller; Graz/AT ([email protected]) Purpose: Manifest pulmonary hypertension is a disease characterized by an elevation in mean pulmonary arterial pressure (mPAP), which is measured invasively via right heart catheterization. Based on magnetic resonance velocity imaging and three-dimensional flow visualization, the periods of existence of a vortex of blood flow in the main pulmonary artery were investigated to examine if they can be used as non-invasive measure of elevated mPAP. Methods and Materials: A total of 46 patients with manifest pulmonary hypertension underwent right heart catheterization and time-resolved, three-dimensional magnetic resonance phase contrast imaging of the main pulmonary artery (with a mean delay of 5 days). Velocity fields resulting from phase contrast measurements were calculated and visualized with dedicated software. Relative periods of existence of a vortex of blood flow in the pulmonary artery (with respect to the cardiac interval) were determined visually and independently by two observers. Results: Observer agreement was high (intraclass correlation coefficient of 0.97). In all 46 patients, a vortex of blood flow in the main pulmonary artery was detected. The Pearson correlation coefficient between the relative period of existence of a vortex and mPAP was 0.94 with 95% confidence interval from 0.89 to 0.97. The standard deviation from the linear regression line was 4 mmHg. Conclusion: Vortices of blood flow in the main pulmonary artery allow an accurate measurement of elevated mean pulmonary arterial pressures. It is anticipated that this method may be a powerful tool for prognostic assessment of manifest pulmonary hypertension. S208 A B C D E F G F H 10:48 Long-term follow-up of patients after corrected tetralogy of fallot: An MRI study M. Grothoff, L. Lehmkuhl, J. Hoffmann, M. Gutberlet; Leipzig/DE ([email protected]) Purpose: Evaluation of volumetric and functional parameters in long-term follow-up examinations after corrected tetralogy of Fallot (TOF) by cardiac MRI. Methods and Materials: 44 pts., 28 male, were studied using a 1.5 T Gyroscan ACS-NT (Philips). Mean age surgical repair was 3.2 years (range 1 month to 51.5 years). Mean age at initial MRI-study was 15.7 years. Further MR-data was acquired each regular outpatient visit (range 0.5 to 11y). Volumetric measurement was performed with a cine gradient echo sequence with breathhold technique. To quantify pulmonary regurgitation-fraction, we performed a velocity encoded flow measurement in the main pulmonary artery in a transverse section. Acquired data was analyzed with a Mann-Whitney-U Test. Results: There was a non significant decrease of right ventricular ejection fraction (p 0.05; mean at first exam. 53%; mean at last exam. 45%). RV end-diastolic volume index increased from 109 to 167 ml/mВІ (p 0.05). Pulmonary regurgitation fraction changed from 28 to 35% (p 0.05). No change could be seen in RV end diastolic wall mass. Conclusion: Cardiac MRI is an excellent method for follow-up examinations in patients after corrected tetralogy of Fallot. Even slight changes in function and volumes can be detected. In long term follow-up late after repair, we found little impairment of ventricular function and a significant increase of right ventricular volume. B-304 10:57 Magnetic resonance-derived three-dimensional blood flow patterns as marker of manifest pulmonary hypertension U. Reiter, G. Reiter, G. Kovacs, B. Kainz, K. Schmidt, R. Maier, H. Olschewski, R. RienmГјller; Graz/AT ([email protected]) Purpose: Manifest pulmonary hypertension is a disease, which is diagnosed invasively via right heart catheterization. Based on magnetic resonance velocity imaging and three-dimensional flow visualization, the existence of a vortex of blood flow in the main pulmonary artery was investigated to examine if it can be used as non-invasive diagnostic criterion for the detection of manifest pulmonary hypertension. Methods and Materials: A total of 93 patients with suspected pulmonary hypertension underwent right heart catheterization and time-resolved, three-dimensional Scientific Sessions magnetic resonance phase contrast imaging of the main pulmonary artery (with a mean delay of 5 days). Catheter-measured mean pulmonary artery pressure exceeding 25 mmHg was used for the diagnosis of manifest pulmonary hypertension. Velocity fields resulting from phase contrast measurements were calculated and visualized with dedicated software. Two observers performed visual analysis of the velocity fields with respect to the existence of vortices of blood flow in the pulmonary artery independently and blinded to the catheter results. Results: Kappa index for the detection of vortices was 1.00. Whereas in all 44 patients with manifest pulmonary hypertension a vortex was found, no vortex was detected in 46 of the 49 patients without manifest pulmonary hypertension. This resulted in a sensitivity of 1.00 and a specificity of 0.94 with 95% confidence intervals from 0.92 to 1.00 and from 0.83 to 0.99. Conclusion: The existence of a vortex of blood flow in the main pulmonary artery allows the accurate identification of manifest pulmonary hypertension. Their measurement can be performed within a routine cardiac magnetic resonance investigation. B-305 11:06 Purpose: To assess the diastolic function in patients with constrictive pericarditis using velocity-encoded flow measurements Methods and Materials: A total of 22 patients with constrictive pericarditis were referred to MRI before pericardectomy, while 20 healthy subjects served as controls. Maximum pericardial thickness, end systolic and end diastolic ventricular volumes and septal motion during diastole were assessed. Velocity-encoded flow measurements were performed at the level of the atrioventricular valves. Maximum velocity of E- and A-waves was measured and the E-/A-wave ratios calculated. The correlation coefficient of E-/A-wave ratios at the tricuspid valve and right ventricular end diastolic pressure (RVEDP) were calculated in patients with CP. Results: Abnormal pericardial thickening was found in 17 of 22 patients with CP and in none of the healthy subjects. The mean right and left ventricular end diastolic volumes were significantly smaller in patients with CP (rvEDV [ml]: 120 p 21 vs. 155 p 20, P 0.001; lvEDV [ml]: 119 p2 7 vs. 152 p 26, P 0.001). Pathologic septal motion was detected in all but one patient with CP and all healthy volunteers had a normal septal configuration during diastole. Measurements at the tricuspid valves showed a significantly lower E-/A-wave ratio in patients with CP in comparison to healthy subjects (1.2 p 0.4 vs. 1.7 p 0.4; P 0.001). The correlation coefficient between the right ventricular E-/A-wave ratios and right ventricular end diastolic pressure measurements in patients with CP was r = 0.589 (P = 0.01). Conclusion: In addition to morphological signs, velocity-encoded flow measurements are a valuable tool in the assessment of diastolic dysfunction in patients with CP and allow detection of increased end diastolic right ventricular pressure. B-306 11:15 Dual energy CT for the assessment of pulmonary perfusion T.R.C. Johnson1, S. Thieme1, C. Lee2, J. McWilliams2, H. Leuchte1, C.R. Becker1, M.F. Reiser1, K. Nikolaou1; 1Munich/DE, 2Los Angeles, CA/US ([email protected]) Purpose: The purpose of this study was to assess the feasibility and potential diagnostic value of dual energy (DE) CT iodine mapping in pulmonary CT angiography (CTA). Methods and Materials: CTA was acquired in DE technique in 93 patients on a dual source CT scanner. Postprocessing was applied to map iodine in the lung parenchyma based on its spectral behavior and the image quality was assessed. Lung perfusion was rated as homogeneous, patchy or with circumscribed defects. Normal CTA images reconstructed from the same data sets were reviewed for the presence and localization of pulmonary embolism (PE), indicating partial or complete embolic occlusion and changes in the lung parenchyma. DE perfusion findings were correlated with those of CTA and lung window in a per-patient and a per-segment analysis. Results: Iodine distribution was homogeneous in 49 patients, of whom CTA showed no PE in 46 and non-occlusive PE in 3 patients. A total of 29 patients had a patchy pattern, of whom 24 had no PE and 5 non-occlusive PE, with solely non-occlusive intravascular clots. A total of 15 patients had segmental or sub-segmental defects, 4 without evidence of PE and 11 with occlusive PE and at least one occlusive clot in the pulmonary vasculature. Conclusion: DECT is reliable in detecting pulmonary defects in pulmonary perfusion corresponding to embolic vessel occlusion. 11:24 Alternative approach in a single breath-hold for right ventricle functional and volumetric quantification G. Ligabue, F. Fiocchi, M. Modena, P. Torricelli; Modena/IT ([email protected]) Purpose: As the evaluation of the right ventricle is reported to be challenging due to its complex anatomy, the aim of the study was to compare the agreement among functional and volumetric parameters of both ventricles depicted by two different MRI sequences. Methods and Materials: Sixty-nine patients (mean age: 53.6 y/o; 32% female) were included. Exclusion criteria were echocardiographic evidence of intra/extra cardiac shunt and valvular disease. The conventional b-FTE sequence on short axis view (10-12 slices; 8 mm thickness; gap = 0.8 mm; SENSE = 1.6; scan time = 102 p 17 sec) was compared to a single breath-hold on horizontal long axis (10 slices over continuous; 8 mm thickness; SENSE = 4; scan time = 26 p 2 sec). In both acquisitions the following functional and volumetric parameters were evaluated for right and left ventricle: stroke volume (SV), end-diastolic volume (EDV), end systolic volume (ESV). Left ventricle indexes on short axis were considered as the reference gold standard. Results: An excellent correlation between the parameters was obtained by both different approaches. SV were as follows: on short axis view left ventricle 81.5 p 18.6 ml (gold standard) and right ventricle 73.1 p 18.9 ml; on horizontal long axis left ventricle 80.7 p 18.9 ml and right ventricle 78.5 p 17.5 ml. The best agreement for right ventricle was obtained by comparing SV on the long axis in a single breath-hold (Pearson r = 0.893; p 0.001) to the gold standard respect to right ventricle evaluation on short axis (Pearson r = 0.89; p 0.001). Conclusion: The evaluation of the right ventricle in a single breath-hold on horizontal long axis allows a high rate of reliability. B-308 11:33 Cardiac magnetic resonance in the assessment of right ventricular involvement in patients with acute and chronic myocardial infarction: Prevalence and prognostic implications M. Mangia, M. Francone, I. Iacucci, F. Vasselli, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: Right ventricular involvement occurs in about one-half patients with inferior AMI and it defines a significant clinical entity associated with considerable immediate morbidity and mortality and a well-delineated set of priorities for its management. Diagnosis is based on clinical findings, early recording of the electrocardiogram and elevated right-sided filling pressures; echocardiographic assessment of the right ventricle (RV) also remains technically difficult. The present study sought to assess the feasibility of late enhancement (LE) cardiac magnetic resonance (CMR) to detect RV infarctions and to evaluate its prevalence. Methods and Materials: A total of 97 patients with acute (n = 58) or chronic myocardial infarction (MI; n = 31) were retrospectively assessed. All patients underwent CMR using a 1.5 T scanner (Siemens Avanto, Germany); imaging protocol included SSFP cine-MR sequences, TSE T2w STIR, 1st pass perfusion and LE imaging acquired after Gd-BOPTA administration (Bracco Multihance, Milan, Italy). Images were analyzed assessing the presence of LE enhancement for each segment and data were matched with both ECG and trans-thoracic echo. Results: Of 97 pts 31 had inferior MI, 62 had anterior MI and 4 had extensive MI. RV LE was observed in 22/97 cases (22%): 13/31 (41%) inferior MI; 9/62 (14%) anterior MIs. In the subgroup of inferior MI, ECG + echocardiography showed RV involvement in 12/22 cases (54%); no hints of RV involvement were observed in the anterior MI pts. RV infarctions showed larger RV ED volumes as compared to others (163 p 27 mL vs 132 p 11 mL P = 0.37). Conclusion: LE CMR is more sensitive than ECG and echocardiography in detecting RV infarction. B-309 11:42 Multidetector row cardiac computed tomography accurately quantifies right ventricular size and function using multiphase contrast-saline mixture injection with dual flow: Comparison with cardiac MRI Y.G. Gao, K. Li, X. Du, Y. Shen; Beijing/CN ([email protected]) Purpose: To explore the value of multiphase contrast-saline mixture injection with dual-flow in measurement of right ventricular (RV) function using ECG-gated multidetector row CT (MDCT) compared with cardiac magnetic resonance (CMR). Methods and Materials: Twenty-six subjects prospectively underwent ECG-gated CT and CMR examinations on a 64 MDCT and 1.5 T MR scanners, respectively. Contrast bolus was followed by a contrast saline mixture at 70:30 ratio on CT examination. Contiguous multiphase short-axis images were generated from axial A B C D E F G H S209 Saturday Correlation of right ventricular end diastolic pressure and E/A ratios in the assessment of diastolic function with MR velocity-encoded flow measurements in patients with constrictive pericarditis K.U. Bauner, M. Schmoeckel, M.F. Reiser, A.M. Huber; Munich/DE ([email protected]) B-307 Scientific Sessions CT data, and steady-state free precession cine MR produced contiguous short-axis cines. Semiautomated software generated ventricular borders to calculate volume, mass, and ejection fraction (EF) from both sets of images. Two experienced radiologists completed quantification of RV function and wall motion analyses of 26 CMR and CT data sets independently. Results: There was a good visualization of the wall of the right ventricle and interventricular septum and a good visualization of uniformity of the right ventricle using multiphase contrast-saline mixture injection with dual-flow. All measures of RV size and function by MDCT correlated well with CMR over a wide range of RV function (RVEF 38-60% by CMR), including end-diastolic volume (r = 0.97), end-systolic volume (r = 0.97), EF (r = 0.97), and mass (r = 0.95). For segments adequately visualized by both techniques, the mean kappa statistic was 0.88, consistent with good agreement. Conclusion: Using multiphase contrast-saline mixture injection with dual-flow, MDCT accurately quantifies RV size and function. RV quantification with cardiac CT requires optimized contrast opacification of the RV. B-310 B-312 11:51 Survived sudden cardiac death of non-coronary origin: Contrast-enhanced cardiac MRI in the differential diagnosis of the underlying pathology P. Hunold1, T. Schlosser2, K. Nassenstein2, O. Bruder2, H. Eggebrecht2, P.W. Radke1, J. Barkhausen1; 1LГјbeck/DE, 2Essen/DE ([email protected]) Purpose: Sudden cardiac death (SCD) is most commonly caused by acute myocardial infarction. However, in cases with normal coronary arteries, SCD often remains unexplained. The aim of this study was to evaluate the use of contrast-enhanced cardiac MRI in defining the underlying pathology of survived SCD without coronary artery occlusion. Methods and Materials: More than 6,000 contrast-enhanced cardiac MRI studies from 3 different hospitals were reviewed for cases of survived SCD with angiographically proven normal coronary arteries. The MRI protocol (1.5 T) consisted of a functional left ventricular study using a segmented SSFP sequence. Data sets for late gadolinium enhancement detection were acquired 8-15 min after 0.2 mmol/kg BW of Gd using a segmented inversion-recovery TurboFLASH / FGRE sequence (TI, 200-260 ms; slice thickness, 8 mm). All cases of non-coronary SCD were reviewed and the different underlying pathologies as defined by MRI were collected. Results: In total, 18 cases were identified. In 14 patients thereof, MRI could state the diagnosis based on typical imaging features: Primary cardiomyopathy was found in 7 patients (arrhythmogenic right ventricular cardiomyopathy, 2; dilated cardiomyopathy, 3; hypertrophic cardiomyopathy, 1; isolated left ventricular noncompaction, 1). Acute myocarditis and acute sarcoidosis were found in 3 patients each. Chronic aneurysm of the anterior wall of unknown origin was found in 1 patient. In 4 patients, no pathology was found. Conclusion: Contrast-enhanced MRI is an utmost valuable tool for the diagnostic work-up of survivors of unclear SCD. This underlines the role of MRI as the first line technique in myocardial disease. 10:30 - 12:00 Room L/M Neuro SS 611 Tumors Moderators: D.P. Auer; Nottingham/UK T.F. Gotwald; Innsbruck/AT B-311 10:30 Impaired peritumoral BOLD signal using cerebral fMRI Z. Jiang, E. Ramos Bombin, E. Barbier, I. Tropres, D. Hoffmann, S. Grand, F. Berger, J.-F. Le Bas, A. Krainik; Grenoble/FR ([email protected]) Purpose: To identify pathophysiological mechanisms associated with impaired peritumoral BOLD signal using fMRI. Methods and Materials: A total of 21 patients referred for resection of primary frontal or parietal neoplasms, respecting primary sensorimotor cortex (SM1) (low grade glioma (LGG) (n = 6); high grade glioma (HGG) (n = 6); menigioma (n = 9)), were examined preoperatively using BOLD fMRI during motor tasks. Whole-brain BOLD signal was estimated using carbogen inhalation. Analyses were conducted using SPM5. Using bolus of gadolinium, cerebral blood flow (CBF) and volume (CBV), and mean transit time (MTT) were estimated. Using a 1 cm3 region-of-interest centered on maximal T-value in SM1 contralateral to movements, interhemispheric asymmetry S210 A B was evaluated using ratios (rSM1 = ipsitumoral SM1/contratumoral SM1) for motor BOLD (rSM1mot), carbogen BOLD (rSM1carbo), and perfusion parameters (rSM1CBF; rSM1CBF; rSM1MTT). Statistical analyses were conducted using SPSSv14. Results: During hand movements contralateral to the tumor, ipsitumoral sensorimotor activations were decreased in HGG and meningioma. Regression analysis showed that distance between tumoral border and SM1 accounted for variance of rSM1mot (B = 0.47). Tumoral volume, CBV, CBF, and MTT were not selected to model rSM1mot. However in meningioma, MTT was increased in ipsitumoral SM1. rSM1mot was correlated to rSM1carbo (R = 0.51). Moreover, 94.5 p 5.2% of motor BOLD activations were included in carbogen BOLD maps. Conclusion: Impaired sensorimotor activations in the peritumoral cortex were detected in HGG and meningioma. In HGG, abnormal neurovascular coupling related to disruption of the brain-blood-barrier is likely, and need further investigations. In meningioma, increased MTT suggests loco-regional hypoperfusion related to a steal phenomenon. Carbogen BOLD maps might be used as spatial mask for fMRI. C D E F G F H 10:39 Role of intra-tumoral diffusion tensor matrices in grading gliomas S.N. Patro, M.B. Jolapara, C. Kesavadas, A.K. Gupta, J. Saini, N.K. Bodhey; Trivandrum/IN ([email protected]) Purpose: Diffusion weighted (DWI) with tensor imaging (DTI) gives information about the amount and directionality of water diffusion occurring in a given tissue. Here, we study the role of diffusion tensor matrices including mean diffusivity (Dav), exponential diffusion (Dexp), fractional anisotropy (FA) and spherical anisotropy (CS) in grading the gliomas. We hypothesize that high-grade tumors, which have increased cellularity, show increased Dexp and FA and decreased Dav and CS. Methods and Materials: We performed DTI in a total of 31 patients, of which 14 had high grade gliomas (HGG, WHO grade III & IV), 15 had low grade (LGG, WHO grade II) and two had diffuse infiltrating gliomas (WHO grade II). We measured Dav, Dexp, FA and CS values in areas of tumor and in normal appearing white matter (centrum semiovale and splenium of corpus callosum). Each patient had undergone either surgery or biopsy. Histopathological diagnosis was established in all cases. Results: The mean Dexp and FA values were higher in HGG (412p123 and 382p92) than LGG (224p47 and 139p36), while mean Dav and CS values were lower in HGG (921p 442 and 650p90) than LGG (1519p198 and 875p31). The difference in the diffusion tensor indices between HGG and LGG was found to be statistically significant with p-value of 0.0001. Diffusion tensor matrices in diffuse infiltrating gliomas were similar to HGG. Conclusion: In addition to conventional MR sequences, the values of diffusion tensor matrices such as Dav, Dexp, FA and CS can help differentiate HGG from LGG. B-313 10:48 Magnetic resonance spectroscopy and perfusion longitudinal follow-up of low-grade gliomas C. Hlaihel1, L. Guilloton1, J. Honnorat2, J. Guyotat2, F. Cotton1; 1Lyon/FR, 2Bron/FR ([email protected]) Purpose: To evaluate the role of proton magnetic resonance spectroscopy associated with MR perfusion in the follow-up of low-grade gliomas, since conventional MR imaging is not sufficient to detect anaplastic transformation. Methods and Materials: A total of 22 patients with histologically proved low-grade glioma were followed up using proton spectroscopy, MR perfusion and conventional MR studies. Follow-up MRIs had been performed on the third month of evolution and then twice a year with a mean of five MR studies per patient. Results: Five patients had an anaplastic transformation. Choline to creatine ratio with a threshold at 2.4 was more efficient than perfusion MR (rCBV) in detecting the transformation, with a sensitivity of 100% and a specificity of 88%. Increased choline seems to appear at an average 15 months before the elevation of rCBV. The mean annual growth was 3.34 mm. A growth rate higher than 3 mm per year was correlated with a greater risk of anaplastic transformation. Conclusion: rChol/Cr elevation may allow an early detection of the anaplastic shift, nearly a year before an elevation of rCBV. Proton magnetic resonance spectroscopy should be recommended in the follow-up of low-grade gliomas since the choline values seem to be modified earlier than MR perfusion. Scientific Sessions B-314 10:57 Astrocytic tumors: Correlation of susceptibility-weighted imaging at 3 T with histopathologic grade M. Hori1, N. Shiraga1, S. Aoki1, H. Mori1, K. Ohtomo1, M. Shimada1, A. Yamaguchi1, T. Araki2; 1Tokyo/JP, 2Yamanashi/JP ([email protected]) B-315 11:06 In comparison of high b-value diffusion-weighted imaging with standard b-value in cerebral gliomas at 3 T MR M. Cihangiroglu1, O. Kilickesmez1, Z. Firat1, N. Comunoglu1, D. Kara1, A. Demir1, U. Ture1, I. Kovanlikaya2; 1Istanbul/TR, 2New York, NY/US ([email protected]) Purpose: To investigate the usefulness of the standard (b=1000 s/mmВІ) and high b value (b=3000 s/mmВІ) DWI in discriminating the high and low grade cerebral gliomas at 3 T MRI. Methods and Materials: 59 patients (38M, 21 F, mean age 43) enrolled in this study. 25 patients had WHO grade IV, 12 patients grade III and 22 patients grade II gliomas. All MR imaging were performed at 3 T MRI (Philips). In quantitative assessment, apparent diffusion coefficient (ADC), signal intensity (SI) ratio (tumor SI/ normal SI), signal to noise ratio (SNR), contrast to noise ratio (CNR), contrast ratio (CR) values were compared between at b=1000 and b=3000 DWI. Results: The difference between SI ratio, SNR and ADC values of grade II and IV gliomas were found statistically significant at b1000 and b3000. SI ratio and SNR values of cerebral gliomas at b3000 are significantly lower than b1000 (p .05). ADC values of grade II and III gliomas at b1000 and SI ratio values of grade II and III gliomas at b3000 were significantly different. ADC values of high grade gliomas at b1000 and b3000 were lower than low grade gliomas (p .05). CR values of grade II and IV were found statistically significant at b3000. In terms of CNR, there was no significant difference between low and high grade gliomas at b1000 and b3000. Conclusion: In addition to differences of SI, SNR and ADC values at both b values, CR value at high b value DWI might contribute in discriminating high and low grade gliomas. B-316 11:15 Using a 64-slice CT perfusion imaging permeability surface to evaluate the histopathologic grade of intracranial gliomas Z. Jiawen1, F. Xiaoyuan1, L. Bin2, Y. Yongqiang2; 1Shanghai/CN, 2Hefei/CN ([email protected]) Purpose: To detect the value of the permeability surface (PS) using a 64-slice CT perfusion imaging in preoperative grading gliomas. Methods and Materials: A total of 31 glioma patients (11 low-grade and 20 highgrade gliomas) underwent 64-slice CT cerebral perfusion examination before operation. Low-grade and high-grade groups were categorized corresponding to WHO grade I or II gliomas and WHO grade III or IV gliomas, respectively, as determined by histopathological examination. The absolute value of PS was obtained from regions of maximal abnormality in tumor parenchyma on PS color perfusion maps. Data were processed using SPSS 11.5 software. The receiver operating characteristic (ROC) curve was used to assess their values in distinguishing the low-grade and high-grade gliomas. B-317 11:24 Differentiating radiation necrosis from recurrent gliomas: Depiction with contrast-enhanced susceptibility-weighted MR imaging correlated with 11C-methionine positron-emission tomography and histopathologic findings T. Nishiguchi, M. Hosono, T. Tada, N. Tsuyuguchi, Y. Inoue; Osaka/JP ([email protected]) Purpose: Determining whether progressively enhancing lesions in patients treated previously are radiation necrosis (RN) or recurrent gliomas remain a challenge. The purpose of this study was to evaluate if intralesional susceptibility effect (SusE) seen with post contrast-enhanced susceptibility weighted imaging (CE-SWI) can provide reliable information for differentiating RN and recurrent gliomas. Methods and Materials: Fourteen progressively enhancing lesions were examined longitudinally on the basis of the following criteria: gliomas treated previously by radiation therapy following histopathological diagnosis, subsequent new progressive enhancement, and inconclusive diagnosis on follow-up MRI. Six lesions were diagnosed as RN according to the result of clinical course and lesion uptake/normal frontal cortex ratio on 11C-methionine positron-emission tomography or histopathology. Eight lesions were histopathologically proved as recurrent gliomas. CE-SWI (TR/TE/flip angle: 48/40/20, resolution 0.7*0.9*1.6 mm) was obtained at 1.5 T for all cases. Qualitative evaluation of the degree and frequency for SusE on CE-SWI was performed compared to the intensity of the vein of Galen. Results: High degree of SusE (H-SusE) was seen in 5/6 (83%) of RN, by contrast noted in 1/8 (12%) of recurrent gliomas. Intermediate to low degree of SusE (Int-SusE) was seen in 4/6 (66%) of RN whereas seen in 6/8 (75%) of recurrent gliomas. Histopathological findings suggested that H-SusE, significantly observed in RN, reflected hemosiderin deposition and calcification, whereas Int-SusE to conglomerate of proliferated vessels. Conclusion: A meticulous analysis of the nature of SusE would provide additional insight into tissue characteristics, and might aid in differentiating RN from recurrent gliomas. B-318 11:33 Cerebral blood volume measurements by perfusion-weighted MR imaging in gliomas: Ready for the prime-time in predicting short-term outcome and recurrent disease? S. Bisdas1, P. Giglio2, I. Burck3, C. Welsh2, I. Xyda4, M. Spampinato2, Z. Rumboldt2; 1TГјbingen/DE, 2Charleston, SC/US, 3Frankfurt/DE, 4GГ¶ttingen/DE ([email protected]) Purpose: To determine whether the relative cerebral volume measurements (rCBV) in gliomas may serve as a surrogate or an adjunct to histopathological WHO-grading in predicting one-year survival and recurrence. Methods and Materials: Thirty-four patients with gliomas (WHO-grade I-IV, 27 astrocytomas) underwent CBV measurements using contrast-enhanced MR imaging. The mean CBV value of a 6x6-pixel region of interest (ROI) and the value of a singlepixel ROI with the maximum CBV across all tumor slices were normalized relative to the normal contralateral cerebral tissue (rCBVmean, rCBVmax). Karnofsky performance score (KPS) and progression free survival (PFS) were recorded. Receiver Operating Characteristic (ROC) curves and Kaplan-Meier survival analysis were conducted separately for the CBV alone and in conjunction with WHO-grade. Results: The rCBVmean and rCBVmax in the astrocytomas were 3.5p2.9 and 3.6p2.7. PFS correlated with rCBV parameters (r=-0.54 to -0.56, pb0.009). WHO-grade was correlated with rCBV values (r=0.65, pb0.0002). rCBVmax 4.2 was found to be a significant cut-off value for recurrence prediction with 77.8% sensitivity and 94.4.% specificity, (p=0.0001); rCBVmax b3.8 was a significant predictor for one-year survival (93.7% sensitivity, 72.7% specificity, p=0.0002). WHO-grade was also predictor for recurrence and one-year survival (equal p-values). The relative risk for shorter PFS was 11.1 times higher for rCBVmax 4.2 (p=0.0006) and 6.7 times for WHO-gradeII A B C D E F G H S211 Saturday Purpose: Susceptibility artifacts on T2*-weighted images appear to be valuable in the evaluation of human astrocytic tumors. The purpose of this study was to evaluate the use of three-dimensional (3D), high-spatial resolution susceptibilityweighted imaging (SWI), which is an emerging MR imaging technique in grading astrocytic tumors. Methods and Materials: A total of 21 patients (5 women and 16 men, mean age 42.3 years) suspected of having astrocytic tumors participated in this study. MR imaging protocol consisted of conventional MR sequences, pre-gadoliniumenhanced SWI and post-gadolinium-enhanced 3D T1-weighetd imaging. In 11cases, post-gadolinium-enhanced SWI were also obtained. All SWI images were evaluated qualitatively by two neuroradiologists. Astrocytic tumors were graded according to the World Health Organization (WHO) classification. Imaging evaluation criteria were: “old susceptibility grade” described in the past literature, hypointensity ratio in the tumor and presence of abnormal enhancement surrounding the tumor. Results: As a result, 18/21 cases were evaluated and 3 were excluded. Mean grading scores of “old susceptibility grade” showed no statistical significance among WHO grades. Mean grading scores of hypointensity ratios in the tumor were higher for WHO grade 3 and 4 than for the rest (P = 0.05, Mann-Whitney U test). Postcontrast SWI images of 5/11 cases (WHO grade 3 and 4) showed bright enhancement surrounding the tumors due to breakdown of the blood brain barrier. Conclusion: The use of SWI provides more information, in addition to conventional sequences, and is useful for the evaluation of astrocytic tumors in vivo, with contrast-enhancement in particular. Results: The PS values of low-grade and high-grade gliomas were (4.16 p 0.76) ml 100 g-1 min-1 and (11.68 p 6.09) ml 100 g-1 min-1, respectively. PS provided significant P-value in differentiating glioma grade (P 0.001) using the Mann-Whitney U test. PS value of gliomas had strong association with the grade of glioma, and the r value was 0.701 (P 0.001) using the Spearman coefficient. The area under the ROC curve was 0.923 for PS. ROC curves revealed better specificity and sensitivity in PS for glioma grade. With a PS cut-off value of 5.13 ml 100 g-1 min-1, sensitivity was 90% and specificity was 90.9% in differentiating high- from low-grade gliomas. Conclusion: PS value using 64-slice CT perfusion imaging provides useful information for the grade of glioma and might have the potential to significantly impact clinical management of gliomas. Scientific Sessions (p=0.05). The combined CBV-WHO-grade classification enhanced the predictive value for recurrence/progression (p 0.0001). Conclusion: rCBV values in astrocytomas are predictive for recurrence and oneyear survival and appear to be more accurate than histopathology grading. B-319 11:42 New WHO classification tumour entities and variants: MR-imaging features in tumours of the posterior fossa S. Puchner, J. FrГјhwald-Pallamar, G. Widhalm, J. Hainfellner, M.M. Thurnher; Vienna/AT ([email protected]) Purpose: To assess the MR imaging features of newly established brain tumour entities and variants according to the 2007 WHO classification of CNS tumours. Methods and Materials: MR images and histological and clinical reports of nine patients (7 male, 2 female, mean age 27 years) with a confirmed diagnosis of rosette-forming glioneural tumour (RGNT) and medulloblastoma variants (anaplastic and medulloblastoma with extensive nodularity) were retrospectively reviewed. The location, signal intensities on T1- and T2-weighted DW MR images, the presence or absence of hemorrhage or calcification, and enhancement pattern were analysed. Results: Three RGNTs were located typically in the fourth ventricular region, whereas one was found in the left cerebellopontine angle. A mass with multicystic appearance without perifocal edema and significant contrast enhancement was seen in 3/4 RGNTs. In one RGNT, inhomogeneous subtle enhancement was observed. Both patients with medulloblastoma with extensive nodularity showed a central scar-like enhancement and signs of diffusion restriction in the solid tumour parts. All three anaplastic medulloblastoma presented as marked, inhomogenously enhancing masses with increased signal intensity on DWI, reflecting high cellular tumour density. Leptomeningeal spread was observed only in anaplastic medulloblastomas. Conclusion: MRI features observed in RGNTs and two new medulloblastoma variants are consistent with their clinico-pathological behavior. RGNTs were seen as a multicystic, non-enhancing tumour of the fourth ventricle region, without significant edema. MRI characteristics of anaplastic medulloblastomas are consistent with tumours of high malignancy. In medulloblastomas with extensive nodularity a “scar-like” central enhancement was observed. Further multicenter studies with larger patient number are necessary for valid conclusions. B-320 11:51 Susceptibility-weighted imaging (SWI) in children with diffuse brainstem glioma during combined anti-angiogenesis and radiation therapy J. Sedlacik1, A. Broniscer1, U. LГ¶bel1, F.H. Laningham1, J.R. Reichenbach2, Z. Patay1, C.M. Hillenbrand1; 1Memphis, TN/US, 2Jena/DE ([email protected]) Purpose: Purpose of this ongoing study is to assess tumor angiogenesis noninvasively by using susceptibility-weighted imaging (SWI) in pediatric patients with high-grade brainstem glioma (BG) treated with an angiogenesis inhibitor and radiation therapy (RT). SWI is sensitive to blood oxygenation and might therefore be an early marker of response to treatment in these highly vascularized tumors. Methods and Materials: 12 patients (age: 2-15 y) with newly diagnosed diffuse BG were enrolled in our IRB-approved study. Patients received local RT for 6 weeks and orally administered Vandetanib while on study. SWI data were acquired under general anesthesia at multiple time points during therapy. Consecutive SWI data in each patient were spatially realigned and regions-of-interest (ROI) analysis was performed in tumor and normal appearing cerebellar white matter (WM). SWI tumor signal was calculated relative to WM to correct for inter- and intra-subject variances. Results: The course of the relative signal intensity (SI), averaged over all patients, showed a significant (p=0.029) drop in tumor tissue shortly after the onset of therapy (1.04p0.05 baseline, 0.99p0.07 after one week of treatment). This signal drop may indicate tumor hypoxia. At subsequent follow-up measurements the SI of the tumor returned to the baseline level. Conclusion: SWI demonstrated a change of tumor signal during combined RT and anti-angiogenic treatment. Whether the observed effect can be attributed to antiangiogenic therapy and/or RT cannot yet be determined due to the study design (i.e., missing control group). However, SWI has shown to be a potential tool for monitoring physiological changes during tumor therapy. S212 A B C D E F G F H 10:30 - 12:00 Room N/O GI Tract SS 601b Esophagus/Stomach: Motility and cancer Moderators: A.Z. Ginai; Rotterdam/NL F. Iafrate; Rome/IT B-321 10:30 Swallowing MR of oro-oesophageal tract and gastro-oesophageal junction with high-speed kinetic sequences: Preliminary study in multiple pathologic conditions I. Sansoni, R. Del Vescovo, G. Della Longa, F. Occhicone, B. Beomonte Zobel; Rome/IT ([email protected]) Purpose: To evaluate the capability of high-speed kinetic MR in evaluating upper and lower swallowing disorders. Methods and Materials: Sixteen patients (4 males, 12 females) with various gastro-oesophageal disorders underwent MR swallowing. MR imaging was performed on a 1.5 T magnet with high performing gradients (amplitude 30 mT/m) with dynamic spoiled gradient echo sequences (Turbo-FLASH) acquired on three oblique planes. The patient was studied lying in supine position, while swallowing yogurt with paramagnetic contrast agent (1 ml of c.m./10 cc of yogurt) during observation after yogurt deglutition and during subsequent Valsalva manoeuvre. We evaluated visualization of oesophageal bolus transit, bolus transit-time, peristalsis, gastro-oesophageal junction patency and competency. Results: MR imaged swallowing abnormalities in all patients: 3 with upper motility disorder, 2 with hypotonic oesophagus, 2 with achalasia, one megaoesophagus, 4 with gastrooesophageal reflux (2 of those with Hjatal Hernia), 2 after Nissen-fundoplicatio, one after gastrectomy. MR findings well correlated with different instrumental findings. Conclusion: High-speed kinetic swallowing MR is a useful and complementary tool for evaluating oesophageal deglutition process and gastro-oesophageal junction alterations. It is simple, non-invasive, rapid and well-tolerated for diagnosing GE reflux or motility disorders, but deserves further investigations. B-322 10:39 MR-fluoroscopy as follow-up examination in patients with achalasia after dilatation treatment V. Panebianco, M. Osimani, S. Bernardo, D. Lisi, E. Santucci, R. Passariello; Rome/IT ([email protected]) Purpose: To evaluate the functionality and morphology of the esophagus in subjects with achalasia, who underwent pneumatic dilatation, using MR-fluoroscopy with dynamic turbo-FLASH sequences acquired during positive oral contrast agent administration Methods and Materials: A total of 20 patients who underwent endoscopic pneumatic dilatation were studied using a 1.5 T magnet (Magnetom Avanto: Siemens, Erlangen, Germany) equipped with a surface phased array coil. Dynamic imaging protocol included turbo-FLASH sequences (TR 416; TE 1.2; FA 8В°; Tck 20 mm; FoV 350; Mat 90 x 128; NВ° Acq. 45; TA = 25 sec) acquired on sagittal, coronal and axial planes during oral administration of positive contrast agent boluses (yoghurt + Gd-DTPA 0.5 M, 1:100). We evaluated the contrast agent transit time, esophageal clearance and esophageal lumen calibre in the two MR-fluoroscopy exams, before and after the dilatation treatment. Results: Good quality images were obtained in all patients, with adequate lumen contrast and a frame rate of 2 frame/sec. All patients had a lumen reduction; in 16 patients we observed both a gain in function and better transit time ( 20 secs) and in half the cases a complete absence of tertiary waves. In only one case did we notice a reduction in the luminal diameter. Conclusion: MR-fluoroscopy approach represents a promising radiation-free modality in the follow-up of patients who underwent dilatation treatment for achalasia. Scientific Sessions B-323 10:48 The performance of hydro-multidetector CT in staging of esophageal cancer in comparison to endscopic ultrasound S. Baroud, N. Bastati, W. Matzek, J. Zacherl, A. Poespuek, A. Ba-Ssalamah; Vienna/AT ([email protected]) B-324 10:57 Pneumo-esophageal 64-MDCT: Is it worthwhile? M. Ulla, E. Levy, M. MuГ±oz, D. Cavadas, A. Seehaus, R. GarcГa-MГіnaco; Buenos Aires/AR ([email protected]) Purpose: To verify the usefulness of this new CT technique in the characterization and stratification of the esophageal wall and the periesophageal tissue. Methods and Materials: A total of 60 patients (mean age: 64 years) with clinical or radiological suspicion of esophageal cancer were examined with pneumo-esophageal 64-MDCT (Pn-64MDCT). To achieve esophageal distension, a 14 F Foley tube was introduced. Continuous airflow was supplied and sustained during the acquisitions, which were performed with a 64-MDCT scanner. Multiplanar, 3D and virtual endoscopy reconstructions were performed. A mural thickening (MT) r3 mm was considered abnormal and reported suspicious of wall infiltration. The results were correlated with the postoperative pathological staging of the surgical specimens. Results: Significant distension of the esophagus (2 cm or more of diameter) including gastro-esophagic transition zone was achieved in all patients. The esophageal lumen was visible in all its extension. In 48/60 patients (12/50 normal findings) MT was identified. All lesions were characterized in size, shape and location. Of 60 MT, 24 were compromising the gastro-esophagic transition zone and Pn-64CT provided better information than the endoscopy and the contrast X ray series. The correlation with postoperative histopathological results was 90 % for MT. Conclusion: Pn-64MDCT proved to be a useful, safe and feasible technique for characterization and stratification of esophageal wall and periesophageal tissue. It provided better characterization of the gastro-esophageal transition zone. It may become a useful tool in the diagnosis and surgical planning of the esophagus and particularly gastric cardia tumors. B-325 11:06 Clinical significance of positive findings of lymph node metastasis using FDG-PET for the prediction of recurrence after esophageal cancer resection S. Okazumi1, K. Shuto2, K. Narushima2, R. Kato1, H. Matsubara2; 1Sakura/JP, 2 Chiba/JP ([email protected]) Purpose: Currently, the amount of cancer cells in metastatic nodes is considered to be important for the prognosis. In this study, we examined the FDG uptake of lymph nodes of esophageal cancer cases preoperatively, estimated the cancer amount in the metastatic lymph nodes of dissected specimen, and investigated the relationship between FDG uptake and postoperative recurrence. Methods and Materials: A total of 43 cases with esophageal cancer underwent esophagectomy with three field lymph node dissection and no preoperative adjuvant therapy. The total number of dissected nodes were 1,773, including 89 metastatic nodes. A 370 MBq of FDG was administered and whole-body PET (GE Advance NXi) was done before esophagectomy. Lymph node uptakes of FDG were evaluated B-326 11:15 Preoperative T staging of gastric carcinoma obtained by MDCT vessel probe reconstructions and correlations with histological findings M. Moschetta, A. Stabile Ianora, A. Scardapane, M. Memeo, P. Pedote, G. Angelelli; Bari/IT ([email protected]) Purpose: This study aims to evaluate the diagnostic accuracy of 16-row MDCT and vessel probe (VP) reconstructions in the T staging of gastric carcinoma. Methods and Materials: 53 patients (39 M, 14 F, mean age 57.5) with endoscopic diagnosis of gastric adenocarcinoma underwent CT examination. A hypotonizing drug was administered and gastric walls were distended by the ingestion of 400-600 ml of water. A biphasic technique with 40s and 70s delay was used after endovenous contrast medium injection. All patients underwent surgery and preoperative and histological staging were compared. Results: T staging diagnostic accuracy was 68% for axial images and 94% for VP reconstructions. In the T1, T2, T3 and T4 parameter evaluation, diagnostic accuracy values were 87, 73.5, 81 and 96%, respectively, for axial images and 96, 96, 98 and 100%, respectively, for VP reconstructions. Conclusion: MDCT is an accurate technique for the preoperative staging of gastric cancer. The VP reconstructions obtained by isotropic data can evaluate the T parameter with a higher accuracy. B-327 11:24 Can CT gastrography replace double-contrast upper gastrointestinal radiography in preoperative visualization and tumor classification of gastric cancers? S. Yeom, H. Ha, H. Kim, S. Park, S. Lee, A. Kim; Seoul/KR ([email protected]) Purpose: To retrospectively compare the capability of multi-detector row computed tomography (CT) gastrography with double-contrast upper gastrointestinal series (UGIS) in the preoperative visualization and classification of pathologically confirmed gastric cancers. Methods and Materials: A total of 157 patients, who underwent both CT gastrography (surface shaded display images) and UGIS after obtaining a pathological diagnosis of gastric cancer, were included in this study. All patients underwent gastric surgeries. Based on the histopathologic results, morphologic features of gastric cancers were classified in accordance with traditional early gastric cancer classification and Borrmann categories for advanced gastric cancer. Two radiologists independently evaluated the capability of CT gastrography and UGIS in visualizing and classifying gastric cancer. Both studies were also separately reviewed without knowledge of the results of the other study. Differences in the capability of CT gastrography and UGI in visualizing and classifying the gastric cancers were assessed with McNemar exact test. Statistical significance was inferred at P 0.05. Results: Histopathologically, 161 gastric cancers were identified in 157 patients, including 67 AGCs and 94 EGCs. The capability in tumor visualization was 95.7% (154 of 161) with UGIS and 88.8% (143 of 161) with CT gastrography (P = 0.013). The overall accuracy for tumor classification was 62.4% (88 of 141) with UGIS and 65.2% (92 of 141) with CT gastrography (P = 0.703). Conclusion: The capability of multi-detector row CT gastrography with surfaceshaded display images appears to be inferior to UGIS in visualizing gastric cancers, but nearly comparable in classifying tumors. A B C D E F G H S213 Saturday Purpose: To evaluate the accuracy of hydro-multidetector CT (HMDCT) in the preoperative staging of esophageal cancer in comparison to endscopic ultrasound (EUS) using the post operative histological results as the gold standard. Methods and Materials: Seventy-two patients (55 male and 17 female with a medium age of 62) were included in the study. All patients underwent endoscopy with simultaneous biopsy and histological verification of the cancer. The stomach and esophagus were distended using 1500L of tap water and effervescent granulate. Local tumor extension, lymph node involvement and distant metastases were assessed. From the 72 patients, 55 underwent additionally EUS. All obtained results were compared with the postoperative histological results according to the TNM classification. Results: Regarding T staging, HMDCT had 54 correct diagnosis and 19 false diagnoses with a sensitivity of 76.5%, accuracy of 74% and PPV of 96%. Regarding N staging, HMDCT had a sensitivity of 64%, specificity of 80%, and accuracy of 73%, PPV of 72% and NPV of 72%. On the other hand, EUS had 20 right diagnoses and 35 false diagnoses regarding T staging with a sensitivity of 37%, accuracy of 36% and PPV of 95%. Regarding N staging, EUS had a sensitivity of 72%, specificity of 57%, an accuracy of 64%, a PPV of 57% and NPV of 73%. Conclusion: HMDCT seems to be superior to EUS in T staging of advanced esophageal cancer. However, EUS seems to be superior to HMDCT in staging of T1 tumors and in N staging. and SUVr3.0 was used as the index of preoperative diagnosis of metastatic node. After operation, the diameter and occupying ratio of cancer cells in each metastatic node on the pathological specimen were examined and compared with its FDG uptake. The uptake was compared with the recurrence ratio after operation. Results: The sensitivity, specificity and accuracy of the PET diagnosis were 95.2, 28.1 and 99.2 %, respectively. The uptakes (SUV) and the diameter occupying ratios were significantly correlated (r = 0.47, P 0.001), and SUV 3.0 group showed significantly higher recurrence within a year (72.9%) than SUV 3.0 group with metastasis (30.7%; P 0.05, log-rank). Conclusion: FDG-PET for the evaluation of lymph nodes is useful for the prediction of postoperative recurrence. The true-positive cases (sensitivity 28%) showed significantly high recurrence and were considered to need adjuvant therapy. Scientific Sessions B-328 11:33 Radiologists’ performance for the differentiation between polypoid early and advanced gastric cancers by using specific CT criteria: Emphasis on dimpling sign E. Lee, S. Kim, J. Lee, S. Kim, M. Kim, J. Han, B. Choi; Seoul/KR ([email protected]) Purpose: To retrospectively determine if there are specific CT features in differentiating between polypoid early and advanced gastric cancers and to determine the radiologists’ performance for the differentiation by using specific CT findings. Methods and Materials: Review of medical records identified 46 patients with 27 polypoid EGCs and 19 polypoid AGCs and with CT scans available for review. Two radiologists retrospectively reviewed CT studies regarding the presence and degree of dimpling at tumor base, the presence of vessel invagination at the dimpling site, thickening of low-attenuating outer layer, perigastric infiltration, and transmural fullthickness enhancement of the lesion. Individual CT findings relevant as predictors were determined using the univariate and multivariate analyses. Individual review of CT scans was then performed by two other radiologists who were blinded to the diagnosis and were known to the results of univariate and multivariate analyses. Individual performance was evaluated by means of ROC analysis. Results: The presence of 3.5 mm severe dimpling at the base of the tumor (31.3) achieved highest odds ratio for the differentiation and followed by vessel invagination (12.3), the presence of dimpling (9.8), perigastric infiltration (5.2), and transmural full-thickness enhancement (4.8). Multivariate analysis showed the presence of 3.5 mm severe dimpling was the only independent variable that differentiated polypoid AGCs from EGCs. The individual accuracy of differentiation using significant CT findings was very good, with AZ values of 0.827 and 0.811. Conclusion: More than 3.5 mm dimpling and other ancillary CT findings are helpful in differentiating between polypoid AGC and EGC and allow good individual accuracy for the differentiation. B-329 Purpose: To evaluate the feasibility of automated CT volumetry for prediction of pathologic response to neoadjuvant chemotherapy of malignant lymph nodes (LNs) in advanced gastric cancer (AGC) patients. Methods and Materials: A total of 36 patients with resectable AGCs (stage rT2N1), treated with neoadjuvant chemotherapy and radical gastric resection, were prospectively enrolled in this study. Before and after chemotherapy, contrastenhanced MDCT was obtained. One radiologist determined the largest LN as the index node (iLN) on pre-chemotherapy CT. The surgeon carefully dissected the iLN. Two pathologists determined the pathologic response of the node on a fivepoint-scale. The longest diameter, area and volume of iLN were calculated using automated volumetry software (Syngo CT Oncology, Siemens). Initial automated segmentation quality was analyzed on a four-point scale and the number of verifications was recorded. Additionally, radiologists manually measured the longest diameter of iLN. For all 36 iLNs, percentage diameter, area and volume reduction rates were calculated and correlated with pathologic regression grades. Results: Mean score of initial automated segmentation quality for 72 iLNs (each 36 on pre- and post-chemotherapy CT) was 3.4 p 0.67, 49 (68.1%) with initial segmentation scores of r3 not requiring additional verification. For the remaining 23 iLNs, the mean number of verification was 1.43. Among the four measurement methods, percentage reduction rates for automatically calculated area and volume showed significant correlation with pathologic regression grades. Correlation coefficient was highest in the percentage volume reduction rate (r = 0.434, P = 0.008). Conclusion: Automated CT volumetry is technically feasible for assessment of LNs. Automated CT volumetry for iLNs is the most accurate tool in the prediction of histopathologic response following neoadjuvant chemotherapy in AGC. A B 11:51 Evaluation of 18 F-FDG PET in advanced gastric cancer: A comparison with CT and surgical histopathology H. Kim, D. Choi, J. Hwang, S. Hong, Y. Kim; Seoul/KR ([email protected]) Purpose: To retrospectively compare 18 F-FDG PET with abdominal CT for advanced gastric cancer (AGC) by using surgical histopathology as the reference standard. Methods and Materials: Surgical specimens were obtained from 21 (14 men, 7 women; mean age 54.9 years) of 49 patients with AGC. Preoperative PET and CT were reviewed for primary tumors and lymph node metastases as compared with surgical histopathology and lymph node dissection. The regional lymph nodes were classified according to the Japanese Research Society for Gastric Cancer. Results: Values for well-differentiated and moderately differentiated versus poorly differentiated adenocarcinoma and signet ring cell carcinoma were 2.69 versus 2.66 (P = 0.970) for the primary lesion (SUV = 2.56) and 1.76 versus 3.81 for the lymph nodes. There were 7 patients (33.3%) without lymph node metastases, 11 (52.4%) in compartment I and II and 3 (14.3%) in compartment III and IV on CT (kappa value = 0.227, P = 0.045); 18 (85.7%), 2 (9.5%) and 1 (4.8%) patient on PET (kappa value = 0.128, P = 0.189); 9 (42.9%), 2 (9.5%) and 10 (47.6%) patients on histopathologic specimens. The overall lymph node detection rate was significantly higher for CT (66.7%) versus PET (14.3%) in operable AGC. Conclusion: 18 F-FDG PET is accurate for primary tumor detection and SUVs for poorly differentiated types were significantly lower than for highly differentiated types of primary lesions and lymph node metastases. 18 F-FDG PET and CT were less sensitive to N staging of AGC and underestimated lymph nodes in compartment III and IV. 10:30 - 12:00 Room Q Interventional Radiology 11:42 Feasibility of automated CT volumetry for neoadjuvant chemotherapy monitoring of malignant lymph nodes in advanced gastric cancer: A prospective study M. Yu, S. Kim, J. Goo, J. Lee, J. Lee, J. Han, B. Choi; Seoul/KR ([email protected]) S214 B-330 C D E F G F H SS 609b Carotid and intracranial interventions Moderators: S. MacDonald; Newcastle upon Tyne/UK L. Pierot; Reims/FR B-331 10:30 Eight years of experience in carotid artery stenting with cerebral protection device F. Fanelli, E. Boatta, P. Rabuffi, A. Pucci, M. Allegritti, R. Passariello; Rome/IT Purpose: To evaluate the results and the technical aspects of eight-year experience in carotid artery stenting (CAS) performed with cerebral protection devices in order to prevent thromboembolic complications. Methods and Materials: From February 2000, 314 patients with internal carotid artery stenosis underwent carotid artery stenting (331 procedures were performed). There were 213 men and 101 women (age 65-87 years, mean 71.4 y). One-hundredtwenty-one patients were symptomatic with stenosis 50% and 193 were asymptomatic with stenosis 80%; 282 primary stenosis and 49 stenosis secondary to TEA were treated. Seventeen patients underwent bilateral stenting. Cerebral protection devices were used in 314 cases; 17 cases (5.1%) were performed without cerebral protection. All cases were performed using self-expandable stents. Cerebral DWMRI examination was also performed before and after the procedure to evaluate neurological complication occurred during CAS. Results: Technical success (residual stenosis 30%) was obtained in all cases (100%). The mean follow-up was 26.5p15.8 months. Thirty-days mortality was 1/314 cases (0.3%). One year mortality was reported in 2/314 cases (6.3%). Six major complications were observed (1.8%): 3 periprocedural major strokes (0.9%) and 3 post-procedural (within 3 days) major strokes (0.9%). In 21 cases (6.3%), embolic material was found inside the cerebral protection. In 4 cases, a moderate itra-stent restenosis was observed (1.2%) and treated with angioplasty in 2 cases with angioplasty and re-stenting in the other two cases. Conclusion: CAS represents a feasible procedure that can be performed in highrisk patients and it is associated with a low restenosis rate. Scientific Sessions B-332 10:39 Comparison of stent free cell area and cerebral lesions after carotid artery stent placement I.Q. Grunwald, K. Karp, W. Reith, P. Papanagiotou, C. Krick; Homburg a.d. Saar/DE ([email protected]) B-333 10:48 Influence of stent preparation on embolic complications during carotid artery stenting S.M. Pilgram, P. Weber, A.M.J. FrГ¶lich, A. Mohr, M. Knauth; GГ¶ttingen/DE ([email protected]) Purpose: Carotid angioplasty and stenting (CAS) is a well established method for the prevention of ischemic stroke. Although CAS can be performed with acceptable complication rates, the risk of periprocedural embolization is relatively high. In this study, we investigated the influence of stent preparation and duration of intervention on microembolic events during CAS, as detected by diffusion-weighted imaging (DWI). Methods and Materials: Prospective study of 47 patients with high grade or symptomatic carotid stenosis undergoing CAS. To detect new DWI lesions, MRIs were performed 24 hours before and after intervention. In a subgroup of patients (n=8), we pre-deployed approx. 70% of the stent (Carotid WallstentВ®, Boston Scientific) in a basin containing heparinized sterile isotonic saline. Duration, subjective degree of difficulty and number of contrast injections during the CAS procedure were also analysed and correlated to the occurrence of new DWI lesions. Results: In the subgroup (n=8) where stents were pre-deployed, significantly less new DWI lesions were detected when compared to standard stent preparation (1.13 vs. 4.15, p=0.012). Regarding procedural duration and difficulty, we found that patients without detectable microembolic events had a significantly lower mean number of contrast injections (6.74 vs. 5.59, p=0.036). Conclusion: Our results suggest that pre-deployment of stents, prior to implantation, can significantly lower the rate of DWI lesions associated with CAS. This may be explained by air microbubbles remaining within the stent cells, which cannot be eliminated with standard preparation procedures. In addition, reducing the number of contrast injections may further decrease periprocedural complications. B-334 10:57 Reperfusion syndrome after carotid stent angioplasty I.Q. Grunwald, M. Politi, P. Papanagiotou, W. Reith, M. Essig; Homburg a.d. Saar/DE ([email protected]) Purpose: This study assesses the incidence and significance of hyperperfusion syndrome occurring after CAS. Methods and Materials: We retrospectively reviewed the prospective database of 417 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or ICH. MR imaging including FLAIR and diffusion weighted imaging was acquired before and after CAS in 269 cases. A Spearman’s Rho non-parametric correlation was performed to determine whether there was a correlation between the occurrence of hyperperfusion syndrome and patients’ age, degree of stenosis on the stented and contralateral side, risk factors such as diabetes, smoking, hypertension, adipositas, gender B-335 11:06 Technical success rates, procedural complications and clinical outcome in stenting of intracranial stenoses F. Brassel1, S. Schotes1, D. Meila1, M. Nolden-Koch1, K. Papke2; 1Duisburg/DE, 2 Lingen/DE ([email protected]) Purpose: To evaluate technical and clinical success rates of stenting for intracranial stenoses. Methods and Materials: 53 patients were treated with 56 intracranial stents. Indications for stent placement were established in interdisciplinary consensus (neurology and neuroradiology). Procedural success parameters were the successful stent deployment, absence of procedural complications and absence of residual stenosis 50%. Clinical success was defined by applying the NIH stroke scale prior to the intervention and before discharge. Results: 53 stents were deployed; in three cases, the stenosis could not be reached with the microcatheter. Procedural complications were 3 minor dissections, 2 severe dissections, 1 subarachnoid hemorrhage, 1 intracranial hemorrhage and 3 vasospasms. Clinical outcome was favourable in 51 patients with NIH score at discharge better or equal compared to prior to the intervention. One patient suffered a minor stroke two days after the intervention. One patient with stenting died as a result of severe intracranial reperfusion bleeding 4 days after the procedure. Conclusion: If performed in an interdisciplinary setting, intracranial stenting has a high technical and clinical success rate. Further follow-up is warranted to define long term results of intracranial stenting. B-336 11:15 Endovascular occlusion of wide-necked aneurysms with stenting and coiling J. Sedat1, Y. Chau1, J. Szapiro2, L. Mondo1, M. Chassang1; 1Nice/FR, 2Bastia/FR ([email protected]) Purpose: To present our single-center experience with endovascular treatment of wide-neck intracranial aneurysms using Neuroform stent associated with coiling, and to evaluate complications, effectiveness, and long-term results of this technique. Methods and Materials: A study of 42 patients with wide-necked cerebral aneurysms treated with a Neuroform stent was performed. Mean aneurysm neck size was 5.33 mm. There were 31 unruptured aneurysms (74%), and 11 aneurysmal subarachnoid hemorrhages (26%). Clinical and angiographic follow-up was available in 38 patients (90.5%). The overall follow-up time ranged from 6 months to 5 years (mean 42 months), but most of the patients (92%) had a follow-up period superior to 1 year. Apart from 3 cases with only 6 months-angiographic-follow-up, the angiographic follow-up was superior to 1 year for the others (92%). Results: Successful deployment of 41 stents for 42 aneurysms (97%) was obtained. Procedural complications were observed in seven cases (16.5%), but permanent procedural morbidity was observed in one patient (2.4%). Long term complete aneurysmal occlusion was obtained in 27 patients (71%). Aneurysmal regrowth was observed in 4 patients (9.5%) on the first control angiogram. After the first control angiogram, no delayed recanalization or regrowth was observed. During the follow-up period, one patient presented a moderate and asymptomatic stenosis into the stent; there were no events of hemorrhage, no delayed thrombosis and no stent displacement, fracture or torsion. Conclusion: These results show effectiveness of the technique, small rate of procedural complications, and long-term tolerance to the Neuroform stent. A B C D E F G H S215 Saturday Purpose: This study examines whether there exists a correlation among closed, semi-closed and open-cell stent design and cerebral ischemic lesions identified by diffusion-weighted magnetic resonance imaging (DW-MRI) after carotid artery stenting (CAS). Methods and Materials: A retrospective review was conducted on a nonrandomized cohort of 194 patients treated with CAS and evaluated by cerebral DWI before and after the intervention. The mean age of these patients was 68.0 p 0.6 years and the mean degree of stenosis on the dependent side was 87.2% p 0.7. Three stent designs were studied: closed-cell (Wallstent), semi-closed-cell (Smart) and open-cell (Zilver). A non-parametric correlation (Spearman's Rho) was performed between the stent free cell area and the number and area of ischemic lesions found after the intervention. Adverse events and neurological assessment were evaluated. Results: A significant correlation was found between the stent free cell area and the number and area of new cerebral ischemic lesions detected on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open cell design (Zilver; 12.76 mmВІ free cell area) than with a closed cell design (Wallstent; 1.08 mmВІ free cell area). However, there was no significant difference in clinical outcome between the three stent groups. Conclusion: Open-cell stent design is related to fewer cerebral ischemic lesions after CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, is not significantly different between patients with different stent designs. and fluoroscopy time, mean area of postprocedural lesions as well as preexisting lesions. Significance was established at P 0.05. Results: Of the 417 carotid arteries that were stented and received MRI, we found a hyperperfusion syndrome in 2.4% (10 cases). Patients with pre-existing brain lesions (old or fresh stroke) were more at risk to develop a hyperperfusion syndrome p=0.022 (Spearman-Rho-test). We could not show any correlation to all other patient characteristics. Conclusion: We could not confirm that older patients with hypertension and impaired hemodynamic reserve are the highest risk situation for developing hyperperfusion syndrome after stent placement. However, there might be a correlation between pre existing brain lesions such as old territorial infarcts and freshly demarked lesions. Scientific Sessions B-337 11:24 Neurointerventions in giant aneurysms: Results in 25 cases L. Karanam, R. Kamble, S. Grahadurai, S. Joseph; Chennai/IN ([email protected]) Purpose: To study efficacy of endovascular management in intracranial giant aneurysms. Methods and Materials: The period of study is 5 years and 5 months (Feb 2003-July 2008) which included 25 patients (7M/18 F, age group 9 to 76 yrs) who presented with symptoms of mass effect, SAH, ICH and infarct. CT/CTA/MRA/DSA done in all patients before treatment, cross compression test done in all patients, BOT done in 13 patients. Patients underwent treatment with parent vessel occlusion, stent assisted coiling, balloon assisted coiling, stent graft, ONYX, stent and ONYX depending on the findings. Clinical and angiographic follow-up done at intervals of 1, 3, 6, 12, 24 and 48 months. Results: 84% (21) of giant aneurysms are found in anterior circulation (supraclinoid ICA-4%, carotid ICA-36%, caroticopthalmic ICA-40%, pcom-4%) and 16% (4) in posterior circulation (basillar-12%, vertebral-4%). Total occlusion is seen in 76% (19) of the cases and partial occlusion in 28% (7) of the cases. Worsening of mass effect seen in 12% (3) of the cases, ICH in 8% (2), thromboembolic events in 12% (3) and vasospasm in 12% (3). Temporary neurological defecits seen in 6 patients and permanent deficits in 3 patients. Death occurred in one patient. On follow-up improvement in mass effect seen in 23 patients (92%) and recanalisation seen in 2 patients (8%) managed conservatively. Mortality rate is 4.0% and morbidity is 16.0%. Conclusion: Endovascular treatment can be the treatment of choice with promising results and acceptable risk in the treatment of giant aneurysms. Treatment with stent assisted coiling, balloon assisted coiling, onyx rather than coiling alone appears to be the best treatment option in giant aneurysms. B-338 11:33 Onyx embolisation of cerebral arterior venous malformations A.K. Gupta, A. Hr, N.K. Bodhey, S.N. Patro, H.S. Pendharkar; Trivandrum/IN ([email protected]) Purpose: To study the efficacy of Onyx embolisation in cerebral AVMs Methods and Materials: Between March 2006 and August 2008, 45 patients with brain AVMs were embolized with Onyx. Patients included 24 males and 21 females with mean age of 28 years (range 10-52 years). Clinical presentation included intractable seizures in 30, parenchymal and intraventricular hemorrhage in 8, SAH from concomitant aneurysm in 1, motor aphasia in 1 and intractable headache in 5 patients. Average Spetzler-Martin grade and AVM volume at presentation was 3 and 18 cm3 respectively. Results: Fifty-nine Onyx embolisation procedures were performed in these patients. A total of 138 feeding pedicles were embolized, averaging 2-3 pedicles per patient. Intra-nidal fistulas were embolized with varying concentration of NBCA. Average estimated size reduction was 75% (range 10-100%). Total angiographic obliteration was achieved in 8, partial embolisation followed by radiosurgery in 25 (90-95% obliteration in 10 and 80-90 % obliteration in 15 patients), partial embolisation followed by surgery in 1, and 11 patients have been advised additional sittings of embolization. Complications occurred in 10 patients, 4 had transient neurological deficits, one each had intraventricular, small parenchymal haematoma and cortical vein thrombosis. Three patients had post embolisation parenchymal haematoma that was surgically evacuated. No mortality was documented. Conclusion: Onyx is a safe new liquid embolic agent for the embolisation of brain AVMs. Complete obliteration can be achieved in small AVMs. Large AVMs can be adequately reduced in size for additional surgical/radiosurgical treatment. B-339 11:42 Endovascular management of direct carotico-cavernous fistula: Long term follow-up A.K. Gupta, N.K. Bodhey, H.S. Pendharkar, S.N. Patro, A.L. Periakaruppan; Trivandrum/IN ([email protected]) Purpose: To evaluate the therapeutic benefits and long term follow-up of endovascular management of direct carotico cavernous fistulae (CCF). Methods and Materials: A total of 97 treated direct CCFs in last 11 years were retrospectively studied. Follow-up was available in 56 patients (from 10 years to 3 months). Forty-four were males and 12 females, age range 6-65 years (mean 30). The etiology was trauma in 49, spontaneous in 6 and iatrogenic in 1 patient. Presentations included headache, pain, proptosis, chemosis, diplopia, visual deficits, tinnitus etc. Baseline work-up included neck vessel Doppler & TCD studies, brain CT/MRI in addition to routine blood investigations and cardiological evaluation. Complete cerebral DSA was performed and site of the fistula was demonstrated with S216 A B C D E F G F H vertebral angiogram and ipsilateral carotid compression. Selective catheterization of the fistula was followed by deployment of balloons, coils or combination. Results: Complete obliteration of the fistula was achieved in 53 (89.83%), moderate filling in 2 (3.38%) and mild residual filling in 4 (6.77%). Significant symptomatic relief was still seen in these patients. Complications included minor ones as balloon deflation and migration in 4, failure of coil detachment in one & major complications as dense hemiplegia in two, and death of four patients (3 with connective tissue disorder and 1 with cortical venous rerouting). Conclusion: Endovascular treatment remains the treatment of choice for effective long term occlusion of CCFs. B-340 11:51 Effect of type of fistula and various embolic materials on the outcome of intracranial dural arteriovenous fistula: Analysis of 73 patients S.N. Patro, A.L. Periakruppan, A.K. Gupta, N.K. Bodhey, H.S. Pendharkar; Trivandrum/IN ([email protected]) Purpose: (1) To analyze the treatment outcome according to the type of DAVF and the embolic material used. (2) To analyze the types of DAVF with aggressive presentation. Methods and Materials: We investigated 73 consecutive patients with mean age 56.3 years, who were diagnosed to have dural arterio venous fistula. According to the five types as described by Cognard, it was classified. Each type was angiographically analyzed for the various aggressive presenting factors. Depending on the type, it was managed and embolized by different materials and routes. Results: Out of all cases, type I fistula was noted in three patients (4%), type IIa in twenty eight (39%), type IIb in seven (9.5%), type IIab in nineteen (26%), type III in six (8%), type IV in nine (12%) and type V in one patient (1%). Transarterial was the most common route used (nearly 40% cases). Fistulae were obliterated with various embolic materials like PVA, onyx, coils, NBCA and alcohol; either single or in combination. Aggressive presentation was significantly associated with presence of venous ectasia and cortical venous reflux on angiograms. Use of combination of embolic materials had better results. Lower grade (up to IIb) had a favorable outcome. Overall mortality rate was 6.8%. Conclusion: The type of dural AVF, venous ectasia and cortical venous reflux are primary determinants for aggressive presentation. Combination of embolic materials with preservation of sinuses will be the optimal method of endovascular therapy. 10:30 - 12:00 Room R Cardiac SS 603b Myocardial perfusion Moderators: K. Gruszczynska; Katowice/PL R. RienmГјller; Graz/AT B-341 10:30 Assessment of myocardial perfusion in rats: Validation of spin-labeling gradient echo imaging against fluorescent microsphere technique as standard of reference A. Jacquier, F. Kober, S. Bun, P.J. Cozzone; Marseille/FR ([email protected]) Purpose: The purpose of this study was to determine the accuracy of arterial spin labeling gradient echo imaging (ASLGRE) in measuring myocardial perfusion in rats using a fluorescent microsphere technique as standard of reference. Methods and Materials: Male Wistar rats (weight = 200-240 g, n = 16) were anesthetized with 2.1% Isoflurane added to1 l/min of pure O2; their heart rate, breathing rate, temperature, O2 saturation and arterial blood pressure were recorded. Myocardial perfusion was assessed in 8 rats on a Bruker, Biospec 4.7T (Bruker, Ettlingen, Germany) using an ECG and respiration-gated IR gradient-echo technique (resolution = 234 Г— 468 ВµmВІ, TE/TR = 1.52/ms, slice thickness 3 mm, sequence duration 25 min at 350 bpm). In the control group (n = 8) myocardial perfusion was assessed using a fluorescent microsphere technique (under 1 l/ min 100% O2): A mixture containing 100,000 fluorescent microspheres (Yellow, 15 p 0.1 Вµm; Triton, San Diego, CA, USA) was injected into the left ventricle. The animals were killed and heart, and blood samples were harvested. The samples were processed and fluorescence was measured. Scientific Sessions Results: There were no significant differences between the groups in terms of heart rate (400 p 20 bpm), breathing rate (50 p 12/min), temperature (36.9 p 0.1), O2 saturation (98 p 1%) or mean blood pressure (9.8 p 0.3 mmHg). There were no statistical differences in myocardial perfusion assessed using ASLGRE (6.5 p 1.4 ml/g/min) and using the fluorescent microsphere technique (5.9 p 2.3 ml/g/min; P = 0.5). The fluorescent microsphere technique provides measurements of left ventricular stroke volume (179 p 63 Вµl/beat), cardiac index (348 p 133 ml/min.kg), total peripheral resistance (0.32 p 0.1 mmHg.min.kg/ml). Conclusion: ASLGRE provides reliable, high-resolution myocardial perfusion measurements. B-342 10:39 MR perfusion of the myocardium: Semiquantitative and quantitative evaluation in comparison to coronary angiography and intracoronary pressure wire examination A.M. Huber, S. Sourbron, J. Rieber, J. SchГ¤fer, K. Bauner, M.F. Reiser; Munich/DE ([email protected]) B-343 10:48 Quantification of left ventricular function, perfusion and viability in chronic microinfarction using multidetector computed tomography, magnetic resonance imaging and histochemical staining M. Carlsson, D. Saloner, A. Martin, C. Stillson, M. Saeed; San Francisco, CA/US ([email protected]) Purpose: To compare 64-slice multidetector computed tomography (MDCT) with magnetic resonance imaging (MRI) and histopathology in quantifying microinfarction and assessing its long-term effects on myocardial perfusion and LV function. Methods and Materials: An XMR-suite was used to catheterized the LAD coronary artery under X-ray and to define the LAD-territory using first-pass MRI during intracoronary injection of 10% Gd-DOTA. The perfusion territory was selectively embolized in six pigs using a small embolic agent (40-120 Вµm, 250,000 count). At 7-8 weeks after microembolization, LV function, first-pass perfusion and delayed contrast enhancement imaging were performed using MDCT and MRI. Histochemical staining (TTC) was used for quantification of microinfarction. Results: The LAD-territory was 32p4% of the LV. There was no significant difference between MR and MDCT measurements of systolic wall thickening at 7-8 weeks. Global LV function did not differ between MRI (end diastolic volume: 92p8 ml, end-systolic volume 48p5 ml and ejection fraction: 47p3%) and MDCT (96p8 ml, 49p3 ml, 49p2%, respectively). MRI detected a perfusion deficit in the embolized territory (significant decrease in max upslope, max signal intensity and longer time to the peak compared to remote), which was not detected by MDCT. Microinfarction size did not differ between MDCT (6.3p0.8% LV), MRI (6.6p0.5% LV) or TTC (7.0p0.6% LV). Conclusion: Modern MDCT and MRI techniques have the sensitivity to quantify chronic microinfarction and demonstrate its effect on LV function. However, MRI is more sensitive than MDCT in the detection of perfusion abnormalities in chronic microinfarction. 10:57 Volumetric quantification of myocardial perfusion using analysis of multidetector-computed tomography 3D data sets: Comparison with nuclear perfusion imaging N. Kachenoura1, F. Veronesi2, J. Lodato1, C. Corsi2, R. Mehta1, B. Newby1, R. Lang1, V. Mor-Avi1; 1Chicago, IL/US, 2Bologna/IT ([email protected]) Purpose: The detection of perfusion abnormalities associated with myocardial infarction (MI) from multi-detector computed tomography (MDCT) images is based on visual interpretation of selected 2D slices. We sought to develop a technique for quantitative 3D analysis of myocardial perfusion and test it against SPECT myocardial perfusion imaging (MPI) reference. Methods and Materials: We studied 44 patients undergoing CT coronary angiography (CTCA): 15 controls and a study group of 29 patients that included 15 patients post MI. MDCT data sets acquired for CTCA were analyzed using custom software to generate a bull’s eye display of myocardial perfusion and calculate a quantitative index of extent and severity of perfusion abnormality, QH, for 16 volumetric segments. Visual interpretation of MDCT-derived bull’s eyes was compared with resting MPI scores on a segment, coronary and patient basis. Quantitative MDCT perfusion data were correlated with rest MPI summed scores and used for objective detection of perfusion defects. Results: MDCT-derived bull’s eyes accurately reflected perfusion defects in agreement with MPI (kappa = 0.70 by territory; 0.79 by patient). Quantitative data agreed with MPI: (1) correlation between summed QH and MPI scores: 0.87 (territory), 0.84 (patient); (2) area under ROC curve 0.87; sensitivity 0.79-0.92, specificity 0.83-0.91, accuracy 0.83-0.89 for objective detection of abnormalities. Conclusion: Our technique for volumetric analysis of MDCT images is feasible and allows accurate objective detection of fixed perfusion defects. Because perfusion information may aid in elucidating the significance of coronary lesions and can be obtained without additional radiation or contrast load, this technique may prove clinically useful. B-345 11:06 Adenosine stress dual energy CT of the heart for diagnosing myocardial ischemia and viability compared with cardiac MRI and SPECT: Initial experience B. Ruzsics, Y. Lee, P. Zwerner, S. Chiaramida, P. Costello, U.J. Schoepf; Charleston, SC/US ([email protected]) Purpose: To evaluate the feasibility of adenosine-stress and delayed enhancement dual energy CT (DECT) for diagnosing fixed/reversible myocardial ischemia and viability compared with cardiac MRI (cMRI) and SPECT. Methods and Materials: A total of 15 patients with known or suspected coronary artery disease underwent: 1) adenosine stress/rest SPECT; 2) adenosine stress/rest perfusion and delayed enhancement cMRI; 3) adenosine stress/rest and delayed enhancement DECT on a dual-source CT system in dual energy mode (A-tube: 140 kV, B-tube: 100 kV). In each patient all three DECT data sets were analyzed for myocardial contrast deficits and delayed enhancement by mapping the iodine content within the myocardium based on different X-ray spectra. Two independent observers evaluated SPECT, cMRI and DECT for fixed/reversible ischemia and cMRI and DECT for delayed enhancement. Results: All patients were successfully imaged with all three modalities. A total of 255 myocardial segments were analyzed, of which 56 were abnormal at cMRI. Interreader agreement for detection of fixed/reversible ischemia and delayed enhancement at DECT was moderate to excellent (k = 0.5 to k = 1). Compared with cMRI, DECT and SPECT had 100% (88%) sensitivity, 99% (96%) specificity and 99% (97%) accuracy for detecting fixed perfusion defects, respectively. Reversible ischemia was detected with 100% (100%) sensitivity, 100% (90%) specificity and 100% (92%) accuracy. Compared with cMRI, DECT-detected myocardial segments showing delayed enhancement with 100% sensitivity, 100% specificity and 100% accuracy. Conclusion: Adenosine stress and delayed enhancement DECT are feasible modalities. Compared to cMRI as the reference standard, DECT shows good agreement for delayed enhancement and equal or better peformance than SPECT for detection of myocardial ischemia. A B C D E F G H S217 Saturday Purpose: To investigate, if a stress examination alone achieves comparable diagnostic accuracy, as a stress and rest examination does, if a quantitative evaluation is used instead of a semiquantitative evaluation. Methods and Materials: A total of 31 patients with CAD underwent 1.5 T MRI and coronary angiography (CA). Stenosis between 50 % and 75 % were evaluated by an intracoronary pressure wire examination (FFR) for their relevance. Signalintensity-time curves of the first pass MR perfusion images (SR-turboFLASH, stress/rest) were analysed by Argus DSA. For the semiquantitative evaluation the upslope value (US) of a linear fit from the foot point to the signal maximum was calculated for 18 segments. For the quantitative evaluation a model independent deconvolution was used to calculate myocardial blood flow (MBF). US and MBF were determined for each segment for stress and rest. The ratio of the stress and rest value for each segment was determined (MPRI). Coronary artery stenosis 75% or 50% with positive FFR 0.75 were considered as hemodynamically relevant. ROC curves were calculated. Results: The values of the area under the ROC curves (AUC) were 0.78, 0.56 and 0.92 for the USStress, USRest and USMPRI evaluation (semiquantitative evaluation). The values for the MBFStress, MBFRest and MBFMPRI (quantitative evaluation) were 0.92, 0.68 and 0.84, respectively. Comparing USMPRI and MBFStress, no significant difference was found (p 0.001). Conclusion: The quantitative model provides identical diagnostic performance, if only a stress examination is used, as a semiquantitative evaluation of stress and rest examination does. B-344 Scientific Sessions B-346 11:15 k-t SENSE accelerated stress myocardial perfusion MRI at 3 Tesla S. Kato, H. Sakuma, M. Nagata, N. Ishida, K. Kitagawa, M. Ishida, H. Nakajima; Tsu/JP ([email protected]) Purpose:To evaluate the feasibility and diagnostic accuracy of high spatial resolution stress myocardial perfusion MRI acquired at every heartbeat by using k-t SENSE and 3 Tesla MR imager. Methods and Materials: A total of 31 patients with suspected coronary artery disease (CAD) were studied. High spatial resolution ( 2 mm) first-pass contrastenhanced MR images were obtained at rest and during stress by using 3.0 T MR imager and k-t SENSE acceleration factor of 5. Saturation recovery TFE images were acquired with TR/TE of 1.5 ms/2.9 ms, FOV = 40 x 30 cm, matrix = 256 x 192, slice thickness = 8 mm. Three short-axis sections of the LV were imaged at every heartbeat. Two observers determined the image quality score (1: poor to 4: excellent) and recorded the presence or absence of respiratory artifacts and endocardial dark rim artifacts using a 16-segment model. Coronary angiography was performed in 12 patients within 2 weeks of stress perfusion MRI. Results: All studies were successfully completed, with the average image quality score of 3.8 p 0.4. Endocardial dark rim artifacts were observed in 17 (3.4%) of 496 segments, but there were no cases in which dark rim artifacts influenced the diagnosis. Respiratory artifacts were found in 11 (2.2%) of 496 segments. The sensitivity, specificity, positive and negative predictive values and accuracy of stress perfusion MRI for detecting significant CAD were 87.5% (7/8), 96.4% (27/28), 87.5% (7/8), 96.4% (27/28) and 94.4% (34/36). Conclusion: High spatial resolution perfusion MRI can be acquired at every heartbeat by using 3 T MR imager and k-t SENSE acceleration. This approach can substantially reduce endocardial dark rim artifacts and allow accurate detection of myocardial ischemia in patients with significant CAD. B-347 11:24 Dose response of the intravascular contrast agent gadofosveset trisodium in MR perfusion imaging of the myocardium A.M. Huber, S. Niedermayr, M. Prompona, C. Cyran, M.F. Reiser; Munich/DE ([email protected]) Purpose: To evaluate the response of gadofosveset (3 doses) in healthy volunteers concerning contamination of a second perfusion scan and saturation effects in the input curve. Methods and Materials: 18 volunteers were examined at 3.0 T using a SRturboFLASH sequence. MR first pass perfusion imaging at rest was performed twice per volunteer with a break of 5 minutes. 3 dose groups were investigated: 0.015 mmol/kg (1), 0.0075 mmol/kg (2) and 0.00385 mmol/kg (3) per perfusion scan. Mean values of the baseline and of the signal maximum derived from the signal-time curves (Argus, DSA) in the myocardium and the left ventricular cavity were determined. $ SI values were determined between baseline and signal maximum. Results: Mean values for the baseline in the myocardium for the first/second perfusion scans were 8.9/16.4, 9.2/13.5 and 8.7/10.9 for groups 1, 2 and 3. Mean baseline values for the LV cavity were 6.9/27.0, 6.8/16.9 and 6.3/10.5. Mean values for the signal maximum in the myocardium were 16.4/20.8, 13.5/16.6 and 10.9/12.9. Mean values for the signal maximum in the LV cavity were 86.7/93.8, 58.7/70.8 and 30.5/35.7 for groups 1, 2 and 3. $ SI showed no significant differences between the first and second perfusion scans for the myocardium and no significant difference in the LV cavity in groups 2 and 3; however, there was a significant difference in group 1 (p 0.05). Conclusion: Contamination of the myocardium plays a minor role in the myocardium; however, saturation effects have an influence on the LV cavity at a dose of 0.015 mmol/kg. B-348 11:33 Perfusion defects in postmenopausal women with micro-vascular angina: An MRI study F. Fiocchi, G. Ligabue, R. Rossi, A. Nuzzo, M. Modena, P. Torricelli; Modena/IT ([email protected]) Purpose: Coronary microcirculation abnormalities have shown to play a role in patients with typical angina and no coronary stenosis (micro-vascular angina). Recent data on women show that these patients may have transient myocardial perfusion abnormalities in response to stress-test. If these perfusion defects are also present at rest, as indicator of microcirculation damage has not been fully investigated and represents the aim of this study. Methods and Materials: We recruited 17 postmenopausal women (mean age 57.6 p 8.7) with typical angina without significant coronary artery disease at S218 A B C D E F G F H coronary angiography (defined as no or minimal luminal narrowing). Each patient underwent first-pass perfusion cardiovascular MRI. Stress imaging was performed using a bolus of dipyridamole (0.84 mg/kg over 6 minutes). Delayed-enhanced MRI study was used to assess the presence of myocardial necrosis. Results: Eight women (48%) showed significant left ventricular fixed perfusion defects (2 in one segment; 4 in two segments; 2 in three segments). The localization of the perfusion defects were anteroapical (n = 3), septal (n = 5) and inferior/ infero-lateral (n = 7). In all patients we found no transient myocardial perfusion abnormalities in response to dypiridamole infusion or delayed enhancement areas. In multivariable analysis, the factors independently linked to the presence of fixed perfusion defects was hypertension (odds ratio = 3.5; 95% CI from 2.8 to 5.4; p 0.0001) and diabetes mellitus (odds ratio = 2.5; 95% CI from 1.8 to 4.3; p 0.001). Conclusion: In susceptible women such as those with typical angina, significant areas of perfusion abnormalities may be visualized by MRI, indicating microcirculation damage despite normal angiogram. B-349 11:42 Identification of residual ischemia in revascularized myocardial infarction using 64-slice MDCT M. Carlsson, A. Furtado, M. Saeed; San Francisco, CA/US ([email protected]) Purpose: To assess the potential of 64-slice MDCT in characterizing revascularized infarcted myocardium at the cellular and microvascular levels. Methods and Materials: Pigs (n=7) underwent 2 hr LAD occlusion/reperfusion. At 2-4 hrs and 1 week first-pass perfusion (FPP) (1 ml/kg of 300 mg/ml Omnipaque) was performed using a dynamic cine (rotation time 60 s/bpm) sequence (mAS/ kV=100/120). Delayed contrast-enhanced images (DE) (mAS/kV=650/120) were acquired every 2 min for 10 min to define infarcted myocardium and microvascular impairment (representing microvascular obstruction and/or no- or low-reflow phenomenon). Max upslope, max attenuation and time to the peak were measured from FPP plots. Hyperenhanced myocardium on DE was measured. Results: In acute infarction, max upslope, maximum attenuation were significantly reduced and time to the peak prolonged in infarcted myocardium (1.8p0.2 s-1, 51.8p2.6 HU, 21.9p3.1 s) compared to remote (7.3p1.4 s-1, 85.3p1.4 HU, 15.1p1.9 s) (P = 0.03). Differential contrast between infarct (145p10 HU) and remote (99p4 HU) myocardium was seen for 10 min on DE-MDCT, but only for 2-4 min between infarct and LV blood pool (166p6 HU). DE-MDCT showed a core of hypoenhancement (2.8p1.8% LV) surrounded by hyperenhancement at 2-4 hrs. Cine-MDCT showed regional increase in anteroseptal wall thickness and lack of regional contractility at 2-4 hrs after reperfusion. At 1 week the hypoenhanced core was almost completely resorbed (0.4p0.1% LV) and the infarction was partially resorbed (10.9p1.3% LV compared to 15.7p1.2% LV at 2-4 hours). Furthermore, the wall swelling had subsided but showed remaining regional dysfunction. Conclusion: 64-slice MDCT has the potential to identify residual ischemia on FPP and monitor resorption of edema, microvascular impairment and infarction on DE images. B-350 11:51 Myocardial perfusion: Comparison of dual energy computed tomography and magnetic resonance imaging, a pilot study J. Ferda1, J. Baxa1, T. Flohr2, B. Schmidt2, B. Kreuzberg1; 1Plzen/CZ, 2Forchheim/DE ([email protected]) Purpose: To compare the assessments of myocardial perfusion using ECG-gated dual energy CT (DECT) and cardiac MRI (CMRI) including perfusion study and late enhancement images. Methods and Materials: The prospectively collected data were evaluated in 10 patients (mean age 72.1 years; 7 males, 3 females) with diabetic microangiopathy (3x), myocardial infarction (4x) and normal findings (3x). Based on informed consent, all patients underwent coronary DECT-angiography and CMRI. After intravenous application of 80 ml of iomeprol (5 ml/s) DECT was executed on a dual-source CT with the application of dual energy data acquisition. The system operated with 140 kV on tube A and with 100 kV on system B, both systems used collimation of 2 x (32 x 0.6 mm). DECT images were analyzed with the algorithm, which allowed to obtain maps of the perfused blood volume in the myocardium. CMRI was performed on a 1.5 T system, including a dynamic turboFLASH T1 sequence after application of 7.5 ml of gadobutrol and an IR-FLASH T1 sequence delayed by 10 minutes. The DECT perfusion blood volume images (DECT-PBV), peak intensity CMRI and LE-MRI were compared. Scientific Sessions Results: Sufficient CT-angiograms of coronary arteries and DECT-BPV images were obtained in all cases; misregistration artifacts of minor importance were noted only in one case. There was good agreement between CT-BPV and peak-intensity CMRI in all cases except one, where an artifact caused by beam hardening was misinterpreted as perfusion deficit on DECT-BPV. Conclusion: DECT exhibited a promising ability in the assessment of the involvement of the coronary arteries and its impact on myocardial perfusion within one examination. 14:00 - 15:30 Room A Musculoskeletal SS 710 Shoulder/Upper extremity Moderators: R. Arkun; Izmir/TR S. Waldt; Munich/DE 14:00 Magnetic resonance arthrography of the glenohumeral joint: Comparison of T1-weighted two-dimensional sequences and volumetric interpolated breathhold examination H.M. Stockley, C. Hutchinson; Manchester/UK ([email protected]) Purpose: To ascertain if there is any difference in the identification of anatomical structures when comparing separately acquired T1-weighted (T1W), two-dimensional (2D) sequences and a volumetric interpolated breathhold examination (VIBE) in magnetic resonance (MR) arthrography of the glenohumeral joint. Also, to investigate if there is any difference between acquiring VIBE sequences in axial or coronal planes. By incorporating VIBE sequences into MR arthrography protocols, total scanning time could be reduced to approximately half its current value. Methods and Materials: A total of 60 patients underwent 1.5-T MR imaging following injection of the glenohumeral joint with diluted gadolinium. The sequences included T1W imaging with fat saturation in the axial, sagittal oblique and coronal oblique planes and T1W VIBE imaging with water excitation in either the coronal oblique or axial plane. Data were compared qualitatively for ease of identification of anatomical structures and the presence of patient movement. Results: Ligaments (P = 0.02), labrum (P = 0.09) and tendons (P = 0.006) were more easily identified on separately acquired T1W 2D sequences compared to VIBE sequences acquired in the axial plane, but differences were not statistically significant when compared to VIBE images acquired in the coronal plane. Cartilage (P 0.001) was more easily recognised on VIBE imaging during which there was less patient movement (P 0.01) compared to T1W 2D imaging. Conclusion: Differences found when comparing anatomical structures on separately acquired T1W 2D sequences with images generated using VIBE, acquired in the axial plane, are shown to be statistically significant. B-352 14:09 Glenoid labrum and articular cartilage lesions of the glenohumeral joint: Diagnostic effectiveness of 3D water-excitation true FISP MR arthrography T.J. Dietrich1, M. Zanetti2, N. Saupe2, C.W.A. Pfirrmann2, S.F. Fucentese2, J. Hodler2; 1MГјnsterlingen/CH, 2Zurich/CH ([email protected]) Purpose: To evaluate the diagnostic effectiveness of MR arthrography using a transverse 3D water-excitation true fast imaging with steady-state precession (FISP) MR arthrography in the detection of labrum and cartilage abnormalities of the glenohumeral joint. Methods and Materials: Seventy-five shoulders were included in this retrospective study. Imaging parameters were: transverse plane; repetition time [msec]/echo time [msec], 9.24/3.17; flip angle, 28В°; field of view, 180 x 158 mm; matrix, 512 x 256; section thickness, 1.7 mm. MR-Imaging reading was performed blinded to clinical information and the arthroscopy report. The anterior and posterior labrum as well as the humeral and glenoidal cartilage were assessed separately. A classification system of three grades was used: normal cartilage, superficial and deep cartilage lesions as well as normal labrum, labral degeneration and labral tear. Arthroscopy served as the reference standard. Results: For the detection of superficial and deep cartilage lesions sensitivity, specificity and accuracy varied between 60 and 93%, 76 and 89%, 76 and 89%. For deep cartilage lesions sensitivity, specificity and accuracy varied between 86 and 100%, 89 and 97%, 90 and 96%. For the diagnosis of labral degeneration and tears sensitivity, specificity and accuracy varied between 25 and 94%, 74 and B-353 14:18 Is a single MR arthrography series in ABER position as accurate in detecting labroligamentous lesions as conventional MR arthography? S.A. Schreinemachers, V.P.M. van der Hulst, W. Willems, S. Bipat, H.-J. van der Woude; Amsterdam/NL ([email protected]) Purpose: To retrospectively compare accuracy of single MR arthrography series in abduction external rotation (ABER) with conventional MR arthrography for the detection and characterization of anteroinferior labroligamentous lesions, with arthroscopy as reference standard. Interobserver variability of both protocols was determined. Methods and Materials: Institutional review board approval was obtained; informed consent was waived. MR arthrograms, including oblique axial fat suppressed T1weighted images in ABER position and conventional imaging directions (SET) of 250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and independently evaluated by three reviewers. Reviewers were blinded to clinical information and arthroscopic results. Labroligamentous lesions were registered in both ABER and SET. The lesions were subclassified (Bankart, Perthes, ALPSA or lesions not otherwise specified). Interobserver agreement was assessed by Kappa statistics for all 250 patients. 92 of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus SET were calculated and compared using paired McNemar test. Results: Kappa-values of the ABER and SET ranged from 0.44-0.56 to 0.44-0.62, respectively. According to arthroscopy 45 of 92 patients had an intact anteroinferior labrum and in 44 patients a labroligamentous lesion (eight Bankart, seven Perthes, 29 ALPSA and three lesions not otherwise specified) was diagnosed. There were no statistically significant differences between ABER and SET regarding sensitivity (83-89% and 88-95%, respectively), specificity (82-95% and 84-91%) and overall accuracy (52- 63% and 55-69%). Conclusion: The results of a single MR arthrography series in ABER position are comparable with those of conventional MR arthrography for detecting labroligamentous lesions. B-354 14:27 Inter- and intraobserver variability of MR arthrography in the detection and classification of superior labral anterior posterior lesions: Evaluation in 75 arthroscopically confirmed cases K. Holzapfel, S. Waldt, J. Paul, M. Bruegel, E.J. Rummeny, K. WГ¶rtler; Munich/DE ([email protected]) Purpose: To determine the inter- and intraobserver variability of MR arthrography (MR-A) of the shoulder in the detection and classification of superior labral anterior posterior (SLAP) lesions. Methods and Materials: MR arthrograms of 75 patients who underwent MR-A prior to arthroscopy were retrospectively analyzed by two blinded readers for the presence and type of SLAP lesions. MR arthrograms were reviewed twice by each reader with a time interval of 4 months between both readings. Sensitivity and specificity for diagnosing SLAP lesions and accuracy for lesion classification were determined for each reader. Inter- and intraobserver agreement for detection and classification of SLAP lesions were calculated using + coefficients. Results: Arthroscopy confirmed 40 SLAP lesions: type I (n = 1), type II (n = 32), type III (n = 4), type IV (n = 3). Compared with arthroscopy, sensitivity, specificity, and accuracy for detecting SLAP lesions by MR-A were 92.5, 82.6 and 88.9% (Reader1) and 92.5, 87.0 and 90.5% (Reader2). MR arthrographic and arthroscopic grading were concurrent in 82.5 and 85.0% of cases. Diagnosis of SLAP lesions was concurrent between both readers in 98.5% and classification of lesions in 95%. Interobserver agreement was almost perfect (+ = 0.90) for the detection and substantial (+ = 0.78) for the classification of SLAP lesions. Intraobserver agreement of both readers was almost perfect for the detection of SLAP lesions (+ = 0.96, + = 0.93). For the classification of SLAP lesions, intraobserver agreement was substantial (+ = 0.79) in one and almost perfect (+ = 0.92) in the other reader. Conclusion: MR-A allows reliable and accurate detection and classification of SLAP lesions with high inter- and intraobserver agreement. A B C D E F G H S219 Saturday B-351 84%, 64 to 86%. For labral tears the corresponding values varied between 33 and 100%, 87 and 89%, 86 and 88%. Conclusion: The diagnostic effectiveness of MR arthrography using a transverse 3D true FISP sequence is useful in the detection of lesions of the labrum and of the thin glenohumeral cartilage. Scientific Sessions B-355 14:36 Magnetic resonance shoulder arthrography: Posterior approach under ultrasonographic guidance and abduction E. Faiella, F. Martina, L. Stellato, F. Carcione, P. Sedati, F. Grasso, B. Beomonte Zobel; Rome/IT ([email protected]) Purpose: To describe the technique performed under ultrasonographic guidance and to assess its efficacy. Methods and Materials: 38 consecutive patients were enrolled in the study, after obtaining informed consent. All the procedures were performed with the left arm (15) or the right arm (23) in abduction, with the corresponding hand over the controlateral scapulae in order to obtain a distension of the posterior capsula. Sterile technique was used and a 22-gauge needle was used. Under ultrasonographic control, the tip of needle was followed until its proper position within the articular cavity and the contrast media was injected. The procedure was performed by an interventional radiologist and one resident in training in interventional radiology; we considered technical results, number of attempts, experienced pain, time of procedure and complication. Results: The procedure was performed in all the cases. The mean time of the procedure was 7.2 p 1.4 min. The pain, on a scale from 0 to 10, was reported as 3.2. One attempt was performed in 31 patients (81%), two in the remaining 7 (18%). No complications were observed. Conclusion: MR shoulder arthrography performed with posterior approach under ultrasonographic guidance and abduction (PAUGA) is a safe, fast and well tolerated technique that can be performed with optimal results with no need of X-ray. B-356 14:45 MR imaging of the intraarticular disc of the acromioclavicular joint at 3.0 T A. Foteinos1, C. Petchprapa2, J. Bencardino2, M. Schweitzer3; 1Peiraeus/GR, 2 New York, NY/US, 3Ottawa, ON/CA ([email protected]) Purpose: To study the MR appearance of the acromioclavicular joint disc at 3.0 T. Methods and Materials: Review of axial PDw images of the shoulder MRI of 48 patients (23 male, 25 female, mean age: 50.9) was performed by two radiologists. The acromioclavicular joint disc was assessed with regard to its presence, signal and morphology, and osteoarthritic (OA) joint changes were also assessed. Statistical analysis estimated reader agreement, possible subject age influence on the likelihood of disc detection and correlations of: (1) subject age with OA changes, disc presence, morphology and signal, and (2) OA changes with disc presence, morphology and signal. Results: A disc was detected by both readers for 36/48 (75%) subjects and kappa coefficient was 0.67, which indicates good agreement. Kappa values were 0.29 for disc presence, 0.21 for morphology, and 0.26 for signal, which indicate fair agreement. Kappa value for OA changes was 0.42, which indicates moderate agreement. There was no significant correlation of subject age with disc presence or signal, but there was a significant positive correlation (P b 0.015) of subject age with disc morphology. There was no significant correlation of OA changes with disc presence or signal, but there was a significant positive correlation of OA changes with disc morphology (Pb0.0064). The significant correlation of OA changes with disc morphology is not a consequence of a mutual dependence on age and gender. Conclusion: Detailed evaluation of the acromioclavicular joint disc is limited even at 3.0 T. However, disc morphology seems to be strongly correlated with OA joint changes. B-357 14:54 MDCT arthrography is accurate for detecting and grading SLAP retears in athletes with prior shoulder surgery M. De Filippo1, M. Onniboni1, R. Averna1, P. Araoz2, F. Pogliacomi1, N. Sverzellati1, M. Zompatori1; 1Parma/IT, 2Rochester, MN/US ([email protected]) Purpose: To evaluate the sensitivity and specificity of MDCT arthrography to detect retears of superior labral anterior to posterior (SLAP) lesions of the shoulder in athletes with previous shoulder surgery and with clinical suspicion of relapse. Methods and Materials: Multidetector CT (MDCT) arthrograms performed in 45 shoulders in 45 professional athletes (35 males, 10 females, mean age 29 years, range 21-38 years) who had arthroscopy within 30 days of the MDCT were retrospectively reviewed. MDCT arthrography was performed after intra-articular injection of contrast material and volumetric acquisition on a 16-detector CT scanner. All examinations were independently reviewed by two experienced musculoskeletal radiologists and disagreements were resolved by a third experienced musculoskeletal radiologist. The sensitivity and specificity of MDCT arthrography for detecting any Snyder type II-IV tear was evaluated, using arthroscopy as the S220 A B C D E F G F H reference standard. The number and percentage of tears in which MDCT arthrography allowed correct Snyder type classification were reported. The interobserver variability of MDCT arthrography for correct Snyder classification was reported using the kappa statistic. Results: Using MDCT arthrography SLAP retears were correctly identified in 35 of 37 patients (sensitivity = 95%) and the absence of SLAP retears identified in 7 of 8 patients (specificity = 88%). MDCT arthrography and arthroscopy grades were concurrent in 30 of 37 of patients with SLAP re-tears (81%). MDCT arthrography interobserver variability was substantial (kappa = 0.76). Conclusion: MDCT arthrography is a useful technique for evaluating SLAP retears and may be an alternative to MRI. B-358 15:03 Virtual glenoidplasty: CT-based patient-specific modeling of glenoid rim defects G. Diederichs1, H. Seim1, H. Meyer1, A.S. Issever1, T.M. Link2, R.J. SchrГ¶der1, M. Scheibel1; 1Berlin/DE, 2San Francisco, CA/US ([email protected]) Purpose: The reconstruction of glenoid bone defects after chronic shoulder instability requires accurate preoperative planning. A method is presented to quantify the defect size and generate a 3D model of the optimal bone graft for augmentation by matching the fractured glenoid with the contralateral side. Methods and Materials: Ten paired shoulders from five body donors (subjects: 3 women, 2 men; mean 85 years) and 60 paired shoulders in 30 patients (controls: 9 women, 21 men; mean 21 years) were examined with CT to determine the bilateral comparability by assessment of the maximum glenoid diameters, surface area and volume. After creation of a glenoid rim defect in the study group, repeated CT scans were superimposed with the data from the contralateral side. The defect size was quantified and the missing fragment virtually reconstructed. Accuracy was evaluated by comparing the virtually repaired glenoid with the predefect scan. Results: There were no significant side-to-side differences in the intact shoulders (P 0.05). After creation of the glenoid defects, there was a mean decrease of 31% in the anteroposterior diameter, 34% in the surface area and 19% in volume. The virtually reconstructed glenoids did not differ significantly from the predefect scans. The average predefect-to-postdefect difference was 3% for the anteroposterior diameter (R2 0.71), 6% for the surface area (R2 0.82) and 4% for the volume (R2 0.98). Conclusion: A precise 3D model of the glenoid bony defect can be generated. The computer simulation provides a virtual model of the bone graft, which may potentially improve arthroscopic bone augmentation. B-359 15:12 Value of real-time sonoelastography in lateral epicondylitis: Comparison of findings between patients and healthy volunteers T. De Zordo, R. Faschingbauer, S. Lill, C. Fink, W. Jaschke, A. Klauser; Innsbruck/AT ([email protected]) Purpose: To evaluate the value of sonoelastography (EUS) in assessing common extensor tendon origins in healthy volunteers and patients complaining of symptoms of lateral epicondylitis. The findings were compared to clinical examination, ultrasound (US) and power Doppler ultrasound (PDUS). Methods and Materials: A total of 38 elbows of 32 consecutive patients (10 men, 22 women) complaining of lateral epicondylitis (6 bilateral) and 44 asymptomatic elbows of 28 healthy volunteers (16 bilateral; 11 men, 17 women) were assessed by using US and EUS. Clinical examination was performed and pain was classified by a visual analogue scale. Results: In healthy volunteers, EUS images showed hard tendon structure in 96.21% and in 3.79% mild alterations were found. Using EUS in patients, 33.33% of tendon thirds showed hard structure but softening of different grades was found in 66.67%, which was significantly different from healthy volunteers (P 0.001). Lateral collateral ligament involvement (10/8) and involvement of the overlaying fascia (11/5) were more commonly detected by EUS. Sensitivity was 100%, specificity 89%, and accuracy 94% with clinical examination as reference standard. Good correlation to US findings was found (R r 0.900). No correlation between US or EUS and PDUS imaging could be detected, but PDUS imaging shows a strong correlation with VAS score. Conclusion: EUS was valuable in the detection of intratendinous and peritendinous alterations of the lateral epicondylitis and enabled differentiation between healthy and symptomatic extensor tendon origins with an excellent sensitivity. An excellent correlation to US was found and EUS was more sensitive in detecting lateral epicondylitis. Scientific Sessions B-360 15:21 Gamekeeper’s thumb: A new US dynamic maneuver to detect the Stener lesion B. Bordet, O. Fantino, J. Borne; Lyon/FR ([email protected]) 14:00 - 15:30 Room B Abdominal Viscera (Solid Organs) SS 701 Pancreas Moderators: M.A. Bali; Brussels/BE G. Morana; Treviso/IT B-361 14:00 Feasibility of pancreatic perfusion imaging with 320-slice dynamic CT S. Kandel, H. Meyer, C. Kloeters, V. Romano, P. Hein, P. Rogalla; Berlin/DE ([email protected]) Purpose: To establish and evaluate a scanning protocol of the pancreas using 320-slice dynamic volume CT in patients with primary pancreatic cancer. Methods and Materials: 20 patients with clinically known or strongly suspected primary pancreatic cancer were scanned. The dynamic CT protocol consisted of 20 intermittent low-dose scans that were applied within 2 minutes. The following scan parameters were used: 100 kV tube voltage, 40 mAs tube current, 0.5 s gantry revolution time, 16 cm collimation, 0.5 mm slice thickness. After intravenous contrast media injection of 60 ml at 10 ml/s and dynamic density measurements in the right ventricle, dynamic scanning was initiated manually. Perfusion was determined with the gradient-relationship technique, time-density-curves and coloured perfusion maps were created. Pancreatic tumour perfusion [1/min] was compared to the perfusion measured in normal pancreatic tissue. Statistic analysis was performed using the Wilcoxon test for paired samples. Results: In all scans, the entire pancreas was completely covered by the 16 cm scanning region. The perfusion values of normal pancreatic tissue ranged from 1.07 to 1.26 min-1, in pancreatic tumours perfusion ranged between 0.17 to 0.59 min-1. Perfusion of pancreatic tumour was significantly lower than in normal pancreatic tissue (p 0.007) in all 20 patients. Total radiation exposure was comparable to the dose deposited by standard tri-phasic pancreas CT scans. Conclusion: Perfusion imaging of the pancreas carries the potential to improve an early characterization of pancreatic disease and may serve as a clinically valuable tool for monitoring therapy response in patients with pancreatic malignancy. B-362 14:09 Preoperative multislice computed tomography for evaluation and the assessment of resection criteria of patients with pancreatic diseases C. Grieser, L. Grajewski, I. Steffen, B. Hamm, J. Langrehr, E. Lopez HГ¤nninen, T. Denecke; Berlin/DE ([email protected]) Purpose: To evaluate the accuracy of multislice computed tomography (MSCT) for preoperative evaluation and the assessment of resection criteria in patients with pancreatic diseases who underwent subsequent exploratory laparoscopy or pancreatic resection. Methods and Materials: A total of 105 patients (age, 21 to 84 years; mean, 57 p 11) who underwent exploratory laparoscopy or pancreatic resection at our institution B-363 14:18 Value of MR diffusion-weighted imaging in differentiating pancreatic carcinoma from chronic mass-forming type pancreatitis on 3 T MR unit B. Song, J. Chen, B. Wu; Chengdu/CN ([email protected]) Purpose: To investigate the value of MR diffusion-weighted imaging (DWI) in differentiating pancreatic carcinoma from chronic mass-forming type pancreatitis on 3 T MR system. Methods and Materials: Twenty patients with 13 pancreatic carcinoma and 7 chronic mass-forming type pancreatitis proven by surgical pathology, as well as 14 healthy volunteers, were studied using routine pancreas MR protocol and DWI on a 3 T MR system. The SE-EPI sequence and ASSET technique were used for DWI and b value was selected at 400, 600, 800 and 1000 s/mm2, respectively. The corresponding apparent diffusion coefficient (ADC) values were measured and statistically analyzed. Results: 1. DWI of the healthy volunteers showed intermediate signals of pancreas. 2. DWI of pancreatic tumor masses showed homogenous high signal intensity relative to the surrounding pancreatic tissue with clear boundary. Under different b values, the tumor ADC values were (1.63p0.235), (1.42p0.126), (1.36p0.170) and (1.26p0.178)Г—10-3 mm2/s, respectively, which were significantly lower than those of non-tumor region: (2.11p0.444)Г—10-3 mm2/s, (1.83p0.230)Г—10-3 mm2/s, (1.81p0.426)Г—10-3 mm2/s, (1.60p0.230)Г—10-3 mm2/s, and of the normal pancreas: (1.85p0.350)Г—10-3 mm2/s, (1.69p0.290)Г—10-3 mm2/s, (1.67p0.268)Г—10-3 mm2/s, (1.42p0.221)Г—10-3 mm2/s. DWI of chronic pancreatitis showed inhomogeneous slightly hyper-intense signal with blurring borders. Under different b values, the ADC values of the inflammatory masses of pancreatitis were (1.69p0.150), (1.56p0.199), (1.59p0.172) and (1.35p0.080)Г—10-3 mm2/s, respectively, which were higher than those of pancreatic carcinoma. When b was set to 800 s/mm2, the difference in ADC values between carcinoma and pancreatitis was statistically significant (P 0.05). Conclusion: MR DWI technique can be very useful in differentiating pancreatic carcinoma from chronic mass-forming type pancreatitis. B-364 14:27 Pancreatic ductal adenocarcinoma versus focal chronic pancreatitis: Qualitative and quantitative evaluation by using diffusion-weighted MRI with parallel imaging technique and multiple b gradient factor values P. Boraschi, F. Donati, C. Bertucci, S. Salemi, R. Gigoni, M. Cossu, C. Bartolozzi, F. Falaschi; Pisa/IT ([email protected]) Purpose: To determine the usefulness of qualitative and quantitative evaluation by using diffusion-weighted MR imaging (DW-MRI) with parallel imaging technique and multiple b gradient factor values in the differential diagnosis between pancreatic ductal adenocarcinoma (PDA) and focal chronic pancreatitis (FCP). Methods and Materials: Twelve patients with PDA and eight cases of FCP (1/8 autoimmune pancreatitis) underwent MR imaging at 1.5 T. After the acquisition of axial T1/T2w sequences and coronal MRCP, DW-MRI was performed using axial breath-hold single-shot spin-echo echo-planar (SE-EPI) sequence (parallel imaging factor, 3); the values of b factor were set at 0, 300, 500, 700 and 1,000 s/ mmВІ. All DW images were blindly interpreted. Qualitative evaluation was performed by consensus reading of two reviewers who graded the presence of lesions on a three-point scale on the basis of their signal intensity on high b value as follows: 0 (no signal); 1 (mild/moderate signal); 2 (strong signal). Quantitative evaluation was performed by two other radiologists in conference, who calculated mean ADC values for each lesion using a b-value of 500 s/mmВІ. A B C D E F G H S221 Saturday Purpose: Thumb metacarpophalangeal joint (MCP) strain is a frequent lesion. When the ulnar collateral ligament (UCL) is torn, the adductor aponeurosis can be jammed under the ligament stump; known as the Stener lesion, this compromises effective healing and requires surgical treatment. We here propose a new dynamic maneuver, flexing-extending the inter-phalangeal joint so as to visualize the UCL and the sliding of the adductor aponeurosis expansion, thus detecting the Stener lesion. Methods and Materials: A prospective study on 56 patients assessed ultrasound (US) detection of the Stener lesion using this maneuver, against surgical data as gold standard. Results: US showed 100% sensitivity in detecting torn ligament (32 patients). All patients with Stener lesions on US underwent surgery, with 95.4% sensitivity and 80% specificity. Conclusion: Thus, US with this new specific maneuver provides reliable and reproducible detection of the Stener lesion. Saving videos allows the medical or surgical correspondent to better understand the US examination. between 2001 and 2006 because of pancreatitis or pancreatic tumour and had preoperative abdominal MSCT (4-to 64-slice-scanners, triphasic contrast protocol) were enrolled retrospectively. MSCT data and multiplanar reformatted images (MPR) were reviewed by two independent blinded observers. Diagnostic criteria were dignity, extrapancreatic tumor expansion, vessel infiltration, pathologic lymphnodes, liver metastasis and the resectability (criteria: M0, no arterial infiltration). Preoperative imaging findings were correlated with intraoperative results. Results: Among all 105 patients, 70 pancreatic tumors and 35 benigne pancreatic diseases were found (accuracy of 98%; ROC analysis, AUC of 0.97). Accuracy for extrapancreatic tumoral expanson for observer 1 (O1) and 2 (O2) was 93% (with MPR, 97%; kappa=1.0), for vessel invasion accuracy was both 99% (100%) for the coliac trunc, 94/95% (100/99%) for the superior mesentery artery, 95/97% (99/100%) for the common hepatic artery, both 98% (both 99%) for the splenic artery (kappa=0.79-1.0). The accuracy of a possible resectability was 90% for O1 (91%) and 88% (90%) for O2 (kappa=0.97). Conclusion: MSCT in combination with MPR is a highly accurate method for the evaluation and the assessment of resection criteria in patients with pancreatic diseases. Scientific Sessions Results: The reviewers graded as “2” all PDA and autoimmune pancreatitis (false positive), whereas the other lesions showed “no signal” on high b value DWI, with sensitivity and specificity of 92 and 100% for the detection of pancreatic malignancy. Mean ADC values were 1.43 p 0.0033 mmВІ/s for PDA and 2.09 p 0.013 mmВІ/s for FCP (P 0.05). Conclusion: Qualitative and quantitative evaluation by using DW-MRI might be helpful in the differential diagnosis between PDA and FCP. DW-MRI can be easily performed as an adjunct to conventional MR study of the pancreas. B-365 14:36 Diffusion-weighted magnetic resonance imaging (DWI) for monitoring of advanced pancreatic adenocarcinoma under chemotherapy C. Losio, M. Orsi, F. De Cobelli, M. Reni, S. Cereda, A. Del Maschio; Milan/IT ([email protected]) Purpose: In advanced pancreatic adenocarcinoma, chemotherapy is essential to relieve symptoms, improving quality of life; however, eventual tumor response is measurable only 2-3 months after treatment. Sensitive to modifications of water diffusivity, DWI is a potential tool to monitor intralesional early changes induced by chemotherapy. Our aim was to test the feasibility and usefulness of pancreatic DWI in this setting. Methods and Materials: 11 patients with advanced pancreatic adenocarcinoma (stage III and IV) underwent MRI with addition of diffusion-weighted-EPI sequences (b=600), before and during a 4-drugs-gemcitabine-based chemotherapeutic treatment (MRI repeated 2 weeks after each cycle for 2 months). Tumor mean areas and apparent diffusion coefficient (ADC) values were assessed and compared during follow-up, by tracing perilesional ROIs on morphologic images and ADC maps. Response was quantified with CT, PET-CT (RECIST criteria) and serum CA19-9 at 2-3 months. Results: DWI was successfully performed in all patients; during chemotherapy, mean lesional ADC showed a statistically significant increase (1.85p0.26 vs 1.52p0.24 mm2/s; P=0.001) compared to baseline 2 weeks after second chemotherapeutic cycle (1 month of treatment), probably due to drug-induced citolysis, while a decrease in size was observable only after fourth cycle (2 months). In non-responder patients, no modifications of ADC were recorded. Conclusion: In pancreatic carcinoma DWI, providing accurate measurements of ADC is sensitive to modifications induced by chemotherapy. During chemotherapy, an increase of ADC values precedes tumor regression; furthermore, this seems to occur only in responder patients, suggesting a possible role of ADC as predictive marker of early response to chemotherapeutic treatment. B-366 14:45 Contrast-enhanced ultrasound of pancreatic lesions: PAMUS (pancreatic multicenter ultrasound study) preliminary results M. D’Onofrio, F. Principe, R. MalagГІ, R. Pozzi Mucelli; Verona/IT ([email protected]) Purpose: To evaluate the possibilities of contrast-enhanced ultrasound (CEUS) in the characterization of pancreatic lesions (solid and cystic) detected at ultrasound (US), referring to pathology as the gold standard. Methods and Materials: From radio-pathologic archives, 809 pancreatic lesions studied with CEUS from 2002 to 2007 were retrospectively considered and reviewed. The lesions had to be pathologically proven to be included in the study. Results: Solid lesions were: 516 ductal adenocarcinomas, 142 endocrine tumors, 18 mass-forming pancreatitis, 11 pseudopapillary tumors, 8 anaplastic carcinomas, 9 metastases, 5 lymphomas and 4 rare tumors (2 leiomiosarcomas, 1 liposarcoma, 1 pancreatoblastoma). Cystic lesions were: 35 mucinous cystoadenomas, 19 serous cystoadenomas, 32 IPMN, 6 pseudocysts, 4 cystoadenocarcinomas. Among the solid lesions, 421/516 (81.6%) adenocarcinomas, 108/142 (76%) endocrine tumors, 13/18 (72.2%) pancreatitis, 7/11 (63.6%) pseudopapillary tumors, 7/8 (87.5%) anaplastic carcinomas, 5/9 (55.5%) metastasis and 3/5 (60%) lymphomas were correctly characterized. Among the cystic lesions, 32/35 (91.4%) mucinous cystoadenomas, 12/19 (63.2%) serous cystoadenomas, 27/32 (84.4%) IPMN, 5/6 (83.3%) pseudocystis and 4/4 (100%) cystoadenocarcinomas were correctly characterized. For solid lesions the CEUS sensitivity, specificity, VPP and VPN, accuracy was respectively 73.8, 91.2, 84.2 and 91.1%; 90.5%. While for cystic lesion sensitivity, specificity, VPP and VPN, accuracy of CEUS was respectively 83.3, 99.2, 70.8 and 99.2%; 98.9 %. Conclusion: CEUS can characterize solid and cystic lesions according to pathology with an accuracy of 90.5 and 98.9 %, respectively. S222 A B C D E F G F H B-367 14:54 Pancreatic involvement in patients with hereditary hemorrhagic telangiectasia J.-P. Pelage, A. Lacout, G. Lesur, J. Roume, A. Beauchet, P. Lacombe; Boulogne/FR ([email protected]) Purpose: To prospectively evaluate the pancreatic involvement in patients with hereditary hemorrhagic telangiectasia (HHT). To report the types of pancreatic abnormalities identified in HHT patients. Methods and Materials: All consecutive patients diagnosed with HHT underwent contrast-enhanced 16-slice multidector row computed tomography (MDCT). The pancreas was carefully evaluated with special emphasis on telangiectases and arteriovenous malformations (AVMs). The size and location of identified telangiectases was recorded. The diameter of the splenic artery was measured and the presence of aneurysms was recorded. Results: Thirty-five patients (19 women and 16 men, mean age 48.4 years) have been enrolled. MDCT detected pancreatic vascular abnormalities in 11 patients (31%). Nine patients had telangiectases and 2 had AVMs. A total of 23 telangiectases and 7 AVMs were identified. Most of the 23 identified telangiectases were located in the cephalic or caudal portions of the pancreas. The mean diameter of telangiectases and AVMs was 4.1 p 1.3 mm and 5.7 p 1.2 mm. In addition, 7 patients (19%) had a sacciform aneurysm of a branch of the splenic artery (mean diameter 8.7 p 3.1 mm) including 4 patients with telangiectases/AVMs. No correlation was found between the presence of pancreatic telangiectases/AVMs and liver and/or lung involvement. There was a trend towards enlarged splenic artery in patients with pancreatic telangiectases/AVMs. Conclusion: Pancreatic telangiectases were considered as a rare finding in patients with HHT. With the use of MDCT, pancreatic abnormalities can be identified in one-third of HHT patients. B-368 15:03 Resectable pancreatic adenocarcinoma: Enhancement pattern at transabdominal contrast-enhanced ultrasonography as preoperative prognostic factor M. D’Onofrio, F. Principe, R. MalagГІ, G. Zamboni, R. Pozzi Mucelli; Verona/IT ([email protected]) Purpose: Tumoral perfusion is a functional features of pancreatic adenocarcinoma resulting from neoangiogenesis. The aim of our study was to determine whether enhancement pattern of pancreatic adenocarcinoma at contrast-enhanced ultrasonography (CEUS) is related to patients prognosis after surgery. Methods and Materials: CEUS of 42 resected adenocarcinomas were retrospectively reviewed. Enhancement at CEUS was scored as: group A=poorly vascularized (presence of avascular areas) or group B=well vascularized (absence of avascular areas). All the lesions were resected and underwent pathological examination assessing tumor differentiation as: undifferentiated (poorly differentiated) or differentiated (moderately and well differentiated) and mean vascular density value (MVD). The results of CEUS enhancement and pathology were correlated (Spearman’s test). Survival analysis was made (Kaplan-Meier method). Results: There were 30 differentiated and 12 undifferentiated adenocarcinoma at pathology. At CEUS 10 lesions were poorly vascularized, while 32 lesions were well vascularized. Good correlation was found between CEUS groups and tumoral differentiation (rs=0.51; p=0.001). Positive strong correlation was observed between CEUS and MVD (rs=0.74; p 0.0001). Median survival in patients with group A vascularization at CEUS was significantly lower than patients with group B (p=0.015). Cox proportional hazard model revealed as predictor of higher mortality the presence of tumor poorly vascularized at CEUS (p=0.0001). Conclusion: CEUS enables accurate depiction the vascularization of adenocarcinoma with a strong correlation to pathology and MVD. The enhancement of adenocarcinoma at CEUS appears to be a valid preoperative prognostic factor. B-369 15:12 US-guided fine-needle aspiration cytology of 545 focal pancreatic lesions: Accuracy and short-term complications G.A. Zamboni, M. D’Onofrio, A. Idili, R. Iozzia, E. Manfrin, R. Pozzi Mucelli; Verona/IT ([email protected]) Purpose: To assess the accuracy and short-term complication rate of US-guided fine-needle aspiration cytology (FNAc) of focal pancreatic lesions. Methods and Materials: We reviewed 545 consecutive US-guided FNAc of focal pancreatic lesions performed between January 2004 and June 2008. FNAc was performed using 20G or 21G needles. The pathologist onsite evaluated material appropriateness and provided the diagnosis. We reviewed the final diagnosis and Scientific Sessions the radiological and medical records of all patients to assess for onset of complications during the procedure or in the short term (b7 days). Results: The study population included 262 females and 283 males. Mean patient age was 62 years (range 25-86). Of all the lesions, 63% were in the head/ uncinate process, 35.2% in the body/tail and for 10 lesions (1.8%) the site was not specified. Sampling was diagnostic in 508/545 (93.2%) cases. Excluding the 37 non-diagnostic samplings, US-guided FNAc had 100% sensitivity, 90.6% specificity, 99.4% positive predictive value and 100% negative predictive value. Final diagnosis was adenocarcinoma in 76.8% patients, endocrine tumor in 3.8%, pancreatitis in 2.4%, metastasis in 0.9%, lymphoma in 0.7%. Of the 545 procedures, 539 (98.9%) were uneventful. In two patients, post-procedure abdominal fluid, not present before the procedure, was noted. Four patients had onset of post-procedure pain, without any finding on subsequent imaging. No major complication occurred. Conclusion: US-guided cytology is a safe and accurate procedure for the correct clinical and therapeutic definition of focal pancreatic lesions. The presence on site of a cytologist allows for a high rate of diagnostic procedures, reducing the need for patient recall. 15:21 Vascular complications after pancreatic transplant: Evaluation with MDCT V. Battaglia, C. Cappelli, S. Mazzeo, G. Caproni, L. Novaria, C. Bartolozzi; Pisa/IT ([email protected]) Purpose: To analyse the role of MDCT in evaluating suspected vascular complications and related parenchymal alterations in patients with transplanted pancreas. Methods and Materials: 86 patients who submitted to pancreatic transplantation (bladder or enteric exocrine drainage) underwent MDCT because of suspected vascular complications, within 1 week - 15 months after transplant. Post-contrastographic study was performed in pancreatic and venous phases. Native and 2D-3D reconstructed images were analysed in order to identify: 1) the presence of vascular complications, 2) glands morphology, and 3) parenchymal enhancement. Gold standards were histological examination after graft removal/laparoscopic biopsy and clinical/MDCT follow-up. Results: 52 patients showed no vascular abnormalities; in all cases, glands dimensions and parenchymal densities ranged between normal values. In 34 patients, MDCT depicted 26 thrombosis (7 arterial, 10 venous, 9 artero-venous); 4 chronic arterial graft stenoses; 2 arterial graft ectasia; 1 arterial graft inflammation; 1 artero-venous fistula. In all artero-venous thromboses and in 6 venous thromboses, parenchyma did not enhance and grafts were explanted. In 4 venous thromboses (increased pancreatic dimensions/decreased enhancements) and in 2 cases of acute arterial thromboses (normal parenchyma), patients underwent successfully heparinic and fibrinolytic therapies, respectively. In 2 arterial thromboses with collateral circula (normal parenchyma) and in 5 chronic arterial thromboses/ stenoses (smaller and calcified parenhyma), no therapy was performed. In all other cases of vessels complications (normal parenchyma), surgical/medical therapies were anyway applied. Conclusion: MDCT has revealed useful in evaluating graft vessels, morphology and parenchymal enhancement. Particularly, in cases of suspected vascular complications, MDCT can help in suggesting the best therapeutic approach. 14:00 - 15:30 Room F1 Interventional Radiology SS 709a Embolisations and biopsies Moderators: M. Given; Dublin/IE T. Roeren; Aarau/CH B-371 14:00 Live 3D-fluoroscopy guidance during needle interventions: Clinical implications and benefits S.J. Braak, M.J. van Strijen, M. van Leersum, H.W. van Es, J.P.M. van Heesewijk; Nieuwegein/NL ([email protected]) Purpose: Demonstrating clinical implication and benefits of live 3D-fluoroscopy guidance for needle interventions. Methods and Materials: This new technology uses a flat panel detector system rotating 180В°-240В° around the patient producing a cone-beam soft tissue CT. Within this 3D-data set, the target lesion and needle entrance are defined avoiding essential structures. After co-registering the 3D-data with the fluoroscopy, the calculated B-372 14:09 Treatment of vascular injury in spinal trauma H. Sahin, O. Sahin, I. Oran, S. Cagli, M. Zileli; Izmir/TR ([email protected]) Purpose: Vascular complications during spinal trauma are fortunately few in number. We retrospectively reviewed vascular injuries encountered after spinal trauma that were diagnosed during the last 5 years in our institution. Methods and Materials: The authors reviewed 15 patients with a mean age of 47 years (5-65 years) having spinal trauma with associated vascular injuries diagnosed by means of catheter angiography. All patients were suspicious for vascular injury after an initial radiological and clinical work-up. Results: Three patients were asymptomatic, while the remaining 12 had symptoms related to vascular injury (6 had neurologic symptoms and the remaining 6 had symptoms unrelated to the nervous system) at the time of admission. Vascular injuries were located in the cervical region in 11 patients, in the lumbar region in 3 and in the thoracic region in 1 patient. The lesions included arteriovenous fistula in five, pseudoaneurysm in six and arterial dissection in four patients. The mechanism of vascular injury included penetrating trauma in six, nonpenetrating trauma in five and iatrogenic penetrating injury in the remaining four patients. Eleven patients were treated endovascularly with persistent elimination of the vascular lesions associated with symptom-free clinical follow-up, two patients were managed medically with a good clinical follow-up and the remaining two were managed symptomatically. Conclusion: The possibility of vascular lesion should be kept in mind when examining patients with spinal trauma, especially with fracture dislocation and penetrating injury. Endovascular therapy allows the elimination of a majority of these potentially dangerous lesions with good long-term clinical follow-up. B-373 14:18 How to predict the site of arterial injury in unstable patients with pelvic fractures by clinical and radiological parameters J. Dormagen1, A. TГ¶tterman2, O. RГёise1, L. Sandvik1, N.-E. KlГёw1; 1Oslo/NO, 2 Uppsala/SE ([email protected]) Purpose: To correlate clinical findings and fracture pattern on pelvic plain film (PXR) in hemodynamically unstable trauma patients with pelvic angiography. Methods and Materials: From 1995 to 2007, 95 patients (66 men) underwent pelvic angiography due to suspected traumatic pelvic bleeding. Mean age was 44 (6-92) years. Fracture location was registered as anterior, posterior, right or left. Arterial injuries (AI) were classified as involving anterior, posterior, right or left pelvic branches of the internal iliac arteries. Multiple logistic regression was used to correlate clinical data and fracture pattern with AI. Results: AI were found in 82 patients (86%). Successful embolization was achieved in 69/73 patients (95%). Motorcycle injury was a risk factor for anterior AI (OR 5.2, 95% CI 1.4-18.7), while car driver injury was associated with left AI (OR 5.5, CI 1.7-18.1). Hemoglobin level 8 g/ml was associated with multiple AI (OR 5.4, CI 1.7-17.7), as was heart rate 100 beats per minutes (OR 3.0, CI 1.1-8.6). Unilateral fracture was associated with ipsilateral AI (right side OR 4.9, CI 1.4-17.3, left side OR 12.0, CI 3.0-48.4) and bilateral fracture was associated with bilateral AI (OR 3.6, CI 1.2-10.7). The risk for multiple AI increased from 20% (one risk factor) to 70% (three risk factors). Conclusion: Prior to angio-embolization of pelvic bleeding, the interventional radiologist should take into account trauma mechanism, hemodynamic status and fracture pattern for selection of access site and identification of AI. A B C D E F G H S223 Saturday B-370 trajectory is then projected on the live fluoroscopy images. Ultrasound-inaccessible lesions were included. At least a planning and a control cone-beam CT to check for accuracy and complications was performed. Results: Since the clinical introduction in October 2006, we performed 121 needle interventions using live 3D-fluoroscopy guidance; 96 (79%) were diagnostic biopsies with a definitive histopathological diagnosis of 94%. Therapeutically performed interventions consisted of abscess drainages (n = 10), vertebroplasty (n = 5), aspirations/nephrostomy (n = 6), embolization (n = 1) and localizations/infiltrations (n = 3). The acceptable safety margin of the needle target was less than 5 mm. Technical success was achieved in 100% checked by a control cone-beam CT. The mean procedure time was 28:52 minutes and fluoroscopy time 3:42 min. There was a minor, self-limiting complication in seven (5.8%) patients (small pneumothorax/ pain/bleeding). Accurate needle interventions with live 3D-fluoroscopy guidance coregistered with previously acquired CT/MRI data is possible. Conclusion: Live 3D-fluoroscopy guidance is a revolutionary new promising technique used for needle interventions. Because of the C-arc architecture there is optimal accessibility. It is accurate, quick and has little complications. The effective dose is significantly lower than that of CT and interventions based on previous CT/MRI data are possible. Scientific Sessions B-374 14:27 Immediate and long-term outcomes of bronchial and non-bronchial artery embolization for the management of haemoptysis J.-Y. Chun, A.-M. Belli; London/UK ([email protected]) Purpose: To evaluate the immediate and long-term results of arterial embolization from moderate to massive haemoptysis, and to identify factors influencing outcome. Methods and Materials: A retrospective analysis was carried out in 50 patients who underwent transarterial embolization for haemoptysis between January 2002 and January 2008. Results: There were 24 men and 26 women with a mean age of 55 years. The most frequent causes of haemoptysis included bronchiectasis (16%), active tuberculosis (12%) and aspergilloma (12%). A total of 126 bronchial and non-bronchial systemic arteries were embolised in 62 procedures. Immediate cessation of haemoptysis was achieved in 43 patients (86%). Cumulative haemoptysis control rates were 81.8% at 1 month, 69.9% at 1 year and 55.9% at 3-5 years. Haemoptysis remained controlled in 36 patients (72%), recurred in 14 (28%) and 11 (22%) required repeat embolization. Nine of the 14 (64.3%) recurrent cases occurred within the first month of embolization. The worst outcomes were observed in aspergilloma patients where all six suffered recurrent bleeding and three (50%) died from massive haemoptysis within the first month. Aspergilloma was also associated with an increased risk of haemoptysis recurrence (p 0.05). Complications of embolization included transient chest pain, false aneurysm and one case of lower limb weakness. Conclusion: Bronchial artery embolisation is an effective and safe procedure for controlling haemoptysis. Non-bronchial and pulmonary arteries may contribute to haemoptysis and these vessels should be actively sought, especially in cases of recurrent or persistent haemoptysis. This is particularly important in aspergilloma, which has a particularly poor prognosis. B-375 14:36 Endovascular treatment of peripheral pulmonary artery pseudoaneurysms and angiographic classifications with therapeutic implications S. Shin, T. Shin, K. Jeon, J. Ryoo, H. Choi; Jinju/KR ([email protected]) Purpose: To classify peripheral pulmonary artery pseudoaneurysms (PAPs) based on angiographic findings and to determine treatment options of the PAPs based on the angiographic classification. Methods and Materials: A total of 21 patients with massive hemoptysis had PAPs that were detected on pulmonary CT angiography (CTA). Underlying diseases were pulmonary tuberculosis (n = 14), fungus ball (4), lung abscess (2) and pneumonia (1). All of the patients underwent bronchial, main pulmonary and selective pulmonary angiography. Type A (four cases) were defined as PAPs, visualized on main pulmonary angiography. Type B (eight cases) were defined as PAPs, visualized on selective pulmonary angioraphy, but not on main pulmonary angiography. Type C (nine cases) were defined as PAPs not depicted on pulmonary angiography and included PAPs visualized only with systemic angiography via the bronchopulmonary shunt. For type A or B, successive embolization of the bronchial and pulmonary arteries was performed. For type C, seven patients underwent bronchial arterial embolization (BAE) alone and two patients underwent BAE and percutaneous injection therapy. Results: Type A or type B PAPs were successfully embolized and hemoptysis was controlled in all patients. Hemoptysis was not controlled in one patient with a type C who underwent only BAE. Conclusion: For type A or B, successive bronchial and pulmonary arterial embolization is an effective treatment strategy. For type C, BAE with and without percutaneous injection therapy seems to be an effective treatment. Therefore, classification of PAPs based on angiographic findings is useful for the endovascular management of PAPs with massive hemoptysis. B-376 14:45 Stent-graft or Amplatzer vascular plug (AVP) with coils: Emerging techniques for percutaneous treatment of visceral artery aneurysms (VAAs) A. Rebonato, M. Citone, L. Greco, N. Maltzeff, V. David, M. Rossi; Rome/IT ([email protected]) Purpose: Therapeutic strategy of VAAs, a rare disease with a high mortality rupture risk, is still controversial. Use of stent-graft or AVP with coils is only occasionally documented. The aim of this work is to evaluate efficacy and technical modalities of these devices according to perioperative and long-term FU. Methods and Materials: Between 2004 and 2008, 14 patients received an endovascular treatment for 10 splenic, 2 hepatic, 2 renal VAAs. Eleven patients had S224 A B C D E F G F H 3-6 cm large aneurysms, and were treated with 2 self-expandable and 9 balloonexpandable stent-grafts. Three patients had 9-13 cm giant splenic aneurysms (GSA):AVP was used to occlude the neck and cut up Teflon g.w. sheaths to fill up the aneurysm. CT-angiography was performed before the procedure and after discharge, at 6 and 12 months. Results: In all cases, angiographic aneurysm exclusion was documented. In 1 case, a hilar splenic artery perforation with peritoneal bleeding was promptly treated with coil-embolization. Patients treated with embolization and also 1/11 treated with stent-graft, had segmental splenic infarction. One of theme, at 1 month, developed 4 cm splenic abscess, successfully treated with antibiotics. Post-procedure CT showed complete aneurysms thrombosis and patency of stent-grafts. At a mean 26 months FU, only one 5 mm kinked endograft was occluded. Conclusion: The stent-graft and the AVP are useful emerging endovascular tools in VAAs treatment. The former are fully respective of vascular anatomy while the latter are faster and safer to use, reducing procedure time and avoiding risk of device distal migration. Long term FU appear to confirm durability of the aneurysm thrombosis. B-377 14:54 Preoperative portal vein embolization using an Amplatzer vascular plug H. Yoo, G.-Y. Ko, D. Gwon, J. Kim, H.-K. Yoon, K.-B. Sung, S. Hwang, S.-G. Lee; Seoul/KR ([email protected]) Purpose: To evaluate the safety and efficacy of preoperative portal vein embolization (PVE) using an Amplatzer vascular plug (AVP). Methods and Materials: A total of 41 patients who underwent PVE using gelatin sponge particles and an AVP were enrolled. The right portal branch was punctured with a 21-gauge needle and then a 6-8 F sheath was introduced. The right portal branches were embolized using gelatin sponges (1-8 mm3 in size) through a 5 F catheter initially and then the AVP was deployed at the first or second order right portal vein. Technical success and complications, recanalization, change in the total estimated liver volumes (TELV), future liver remnant (FLR) and FLR/TELV were evaluated. Follow-up CT was obtained 1-43 days (median 16) after PVE for evaluation of the volume parameters. Results: PVE was technically successful in 40 of 41 patients. Major complications occurred in two patients including extensive portal vein thrombosis owing to AVP migration and liver abscess, respectively. Partial recanalization of occluded portal vein was seen in one patient. Pre- and post-PVE, the mean volumes of the FLR and the ratio of the FLR/ TELV were 532 ml p 154, 653 ml p 174 (P 0.001) and 36% p 7, 43% p 8 (P 0.001), respectively. Conclusion: PVE using the AVP seems to be a relatively safe and effective modality for inducing hypertrophy of the FRL with minimal risk of recanalization. However, one should keep in mind the risk of extensive thrombosis owing to AVP protrusion into the main portal vein. B-378 15:03 Interventional radiological procedures in the treatment of complications after liver transplantation: Nineteen years of experience P. Hallscheidt, R. Lopez-Benitez, H.-U. Kauczor; Heidelberg/DE ([email protected]) Purpose: The aim of this study is to evaluate interventional radiological procedures (IRP) in liver transplant (LTX) patients. These include procedures for biliary, arterial, venous and portal complications, as well as the treatment of infected and noninfected fluid collections. Methods and Materials: This retrospective study covered 583 patients (mean age: 44p14 years) in whom a total of 685 LTX were performed from August 1987 to April 2005. Results: Overall, 182 LTX patients underwent a total of 428 IRP, including digital subtraction angiography (DSA) (n=152 /35.51%), percutaneous transluminal angioplasty (PTA) (n=4 /0.93%) and PTA + stent (n=7 /1.63%) of arterial anastomosis, PTA + stent of the celiac trunk (n=2 /0.46%), transjugular intrahepatic portosystemic shunt (TIPSS) (n=2 /0.46%), arterial lysis (n=4/0.93 %), venous lysis (n=2/0.46%), inferior vena cava stenting (n=2/0.46%), percutaneous biliary drainage (PCBD) (n=34/7.94%), percutaneous transluminal dilatation (PTD) of the biliodigestive anastomosis (n=16/3.73%), biliary stent (n=5/1.16%), intrahepatic biliary flushing treatment (IBFT), stone and cast biliary extraction (n=27 /6.30%), other interventions (e.g., embolization in other regions, transjugular liver biopsies, lymphangiographies) (n=9 /2.10%), and ultrasound (US)- and computer tomography (CT)-guided biopsies and percutaneous drainage (n=153 /35.74%). The overall success rate was 85.7%. Conclusion: Technical improvements in LTX and interventional radiology permit vascular and biliary complications to be treated successfully by interventional radiology. Scientific Sessions B-379 15:12 Percutaneous transhepatic liver biopsy with gelfoam tract embolisation: Efficacy and safety E.T.H. Liu, S.K. Venkatesh; Singapore/SG ([email protected]) B-380 15:21 High field MR-guided biopsies with a new MR-compatible assistance system: Technique and first results S. Zangos, K. Eichler, M.G. Mack, C. MГјller, M. Heller, A. Thalhammer, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: The purpose of this study was to examine the feasibility and safety of MR-guided biopsies in patients with suspicious lesions using a new MR-compatible assistance system in a high-field MR-system. Methods and Materials: A total of 20 patients with suspicious focal prostate lesions detected by high-field MR imaging and 5 patients with retroperitoneal lesions were biopsied in a high-field MR-system (1.5 T, Sonata, Siemens) using a new MR-compatible assistance system (Innomotion; Innomedic; Herxheim). The procedures were guided using T1-weighted FLASH and T2-weighted TSE sequences. A servopneumatic drive moves the AMO to the insertion point. The physician introduced the punction needle manually and biopsies were taken in coaxial technique through a 15-gauge pencil tip with a 16-gauge biopsy handy. Complications and biopsy findings were documented. Results: An accurate punction could be easily performed using this new system in a high-field system. No side effects or complications were observed in all patients. Pathological findings revealed sufficient probes in 24 cases and insufficient material in 1 case, due to technical problems with the biopsy device. This problem was corrected with a modification of the software. The T2-weighted images are superior for the evaluation of the anatomy and the needle position during the interventions. Conclusion: Our results indicate that this MR-guided assistance system is suitable for an accurately needle placement for histological clarification of suspicious prostate retroperitoneal lesions in a high-field MR system. Room G/H Head and Neck SS 708 Developmental, autoimmune and parotid disorders Moderators: J.A. Castelijns; Amsterdam/NL C. SchГјller-Weidekamm; Vienna/AT B-381 14:00 Fetal MR imaging of cranio-facial and neck mass lesions and utility of cine sequence K. Shekdar, T. Feygin, L. Bilaniuk, R.A. Zimmerman; Philadelphia, PA/US ([email protected]) Purpose: The purpose of our study is to demonstrate the utility of MR imaging of fetal cranio-facial and neck anomalies with particular reference to cine imaging technique. Methods and Materials: We retrospectively reviewed 115 fetal MR examinations performed at our institution, in patients with suspected head and neck anomalies by ultrasonography, during the time period September 2000 to June 2007. The fetal age ranged from 19 to 32 weeks. All studies were performed on 1.5 Tesla Siemens MAGNETOM Vision and Avanto Systems. Results: The spectrum of head and neck masses in our patient series included: cervical lymphangiomas, cervical and skull base teratomas, cervical veno-lymphatic malformations, thyroglossal duct cyst, cleft lip and palate and arachnoid cyst of the skull base. Cases of craniosynostoses are also incuded in the series. MR imaging provided morphological information for better characterization of the masses. It also provided information regarding fetal swallowing and airway obstruction. Conclusion: Fetal MR imaging along with cine imaging technique is very useful in delineation of cranio-facial and neck lesions. Cine imaging provides critical information regarding fetal swallowing and airway obstruction. This information is valuable in guiding in utero management and in planning delivery and postnatal management. B-382 14:09 The face predicts the brain: The association of facial malformations and brain anomalies in fetuses with trisomy 13 in fetal MRI S.F. Nemec, P.C. Brugger, C. Koelblinger, C. Czerny, D. Prayer; Vienna/AT Purpose: Since the 1960s, the literature describes that congenital facial malformations can predict brain anomalies. Therefore, findings in facial malformations in fetuses with trisomy 13 were reviewed in fetal MRI, which allows visualizing the viscero-neuro-cranium and were correlated with potential brain anomalies. Methods and Materials: This retrospective study included ten fetuses (16-34 gestational weeks) with trisomy 13 and facial malformations, depicted in fetal MRI. In addition to a standard MRI protocol, the following dedicated sequences were used to image the viscero-neuro-cranium: An axial T1-weighted (w) sequence; axial, coronal and sagittal T2-w sequences; a 3D thick-slab T2-w sequence; a coronal single shot fast field echo sequence; and axial and coronal diffusion weighted imaging. The evaluation focused on facial and brain structures and, additionally, on extracranial organ systems. Results: Midface malformations that consisted of cyclopia (one), microphthalmia (one) and hypotelorism (four); of arhinia (four), proboscis (two) and flat nose (two); and of median facial cleft (one) and lip-palate-jaw clefts (five) were associated with semilobar (six) and alobar (two) holoprosencephaly. Furthermore, MRI demonstrated pachygyria (four), a missing olfactory nerve (six), a missing optic nerve (one), a frontoethmoidal meningoencephalocele (one), an epipharyngeal meningocele (one) and small liquor spaces (one), respectively. Extracranial malformations were seen in all ten fetuses. Conclusion: As fetal MRI is able to demonstrate both - facial and brain anomalies - in trisomy 13, the clinical concept of “The face predicts the brain.” can be also reversed to “The brain predicts the face.” reflecting the evolutionary unity of facio-cranial malformations. A B C D E F G H S225 Saturday Purpose: To determine the efficacy and safety of the use of gelfoam tract embolisation following percutaneous transhepatic liver biopsy. Methods and Materials: A total of 165 patients who underwent percutaneous liver biopsy over a 1.5 year period were retrospectively reviewed. Biopsies were performed with either 15- or 18- gauge automated core biopsy needle. Track embolization with gelfoam was performed in 46 patients considered to be at high risk for bleeding. All patients were followed up for a minimum period of 24 hours post procedure. The data collected included patient’s demographics, indications for liver biopsy, number of needle passes performed and histological description of the specimens. Results: Histological tissue samples obtained per procedure ranged from 1 to 6 (mean 3.1 sample). A total of 210 and 123 liver biopsy samples were obtained from those without and those with gelfoam track embolization, respectively. Accurate tissue diagnosis was achieved in all cases (100%). Complications observed include hemoperitoneum, local bleeding and pain. Six complications (2.8% per sample) were encountered in those where non-gelfoam cases compared with four complications (3.2% per sample) encountered where gelfoam was used. This is comparable with complication rates published in literature for transhepatic biopsies studies without embolisation and normal coagulation profile, which range from 0.1 to 3.6% and better than the transjugular route with a complication rate of up to 9%. Conclusion: Percutaneous liver biopsy with track embolisation using gelfoam plugs is a safe technique with low complication rate and a safer alternative to transjugular biopsies in patients with coagulopathy. 14:00 - 15:30 Scientific Sessions B-383 14:18 Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings B. Yang; Beijing/CN ([email protected]) Purpose: To study the computed tomography (CT) and magnetic resonance imaging (MRI) features of sphenoid sinus ectopic pituitary adenomas (EPAs). Methods and Materials: A retrospective review of 249 imaging-detected sphenoid sinus lesions over a 6-year period revealed eight patients with histology-proven EPAs. All eight patients underwent CT and MRI. The following imaging features were reviewed: (a) size, (b) margin, (c) CT attenuation characteristics and (d) MRI signal intensity. In addition, the involvement of adjacent structures and the timeintensity curve (TIC) of dynamic MRI were analysed. Results: Sphenoid sinus EPAs constituted 3% of the sphenoid sinus lesions in this series. All EPAs have well-defined margins and show no relationship to the intrasellar pituitary gland. The mean size is 28 mm (range, 20-46 mm). On nonenhanced CT, the lesions appear as isodense to gray matter in seven (88%) and hypodense in one (12%) patient. On T1WI, EPAs appear to be isointense in six (75%) patients and hypointense in two (25%) patients. On T2WI, the lesions appear to be hyperintense in two (25%) patients and isointense in six (75%) patients. EPAs show moderate heterogeneous contrast enhancement. Two patients had dynamic contrast enhancement MRI and the TIC showed rapid enhancing and slow wash-out pattern. The following features are also seen: (i) empty sella (five patients, 62.5%), (ii) bone changes (five patients, 62.5%), and (iii) involvement of cavernous sinus (five patients, 62.5%). Conclusion: A high index of suspicion for EPAs and a familiarity with imaging findings may help to accurately diagnose this rare entity. B-384 14:27 Wegener granulomatosis of the paranasal sinuses and temporal bone: Is MRI worth using? D. Farina, R. Longaretti, M. Ravanelli, A. Borghesi, R. Maroldi; Brescia/IT ([email protected]) Purpose: To assess the role of MRI in detecting paranasal sinuses (PNS) and temporal bone (TB) involvement in Wegener granulomatosis (WG). Methods and Materials: MRI examinations of 37 consecutive patients affected by WG in its active phase were retrospectively reviewed. MRI protocol included TSET2, SET1 and, after contrast application, both 3DGE and SET1. PNS and TB lesions were scored as: aspecific, when signal pattern was indistinguishable from aspecific chronic inflammation; specific, when masses were detected, when mucosal/ submucosal hypo-T2 lesions were seen in the PNS and when enhancement was detected in the TB. In all cases, MRI and clinical findings were matched. Results: Of 37 patients, 22 (59.4%) had clinical signs and symptoms of PNS involvement: MRI showed specific findings in 13/37 (10/13 symptomatic) and was negative in 7/37 (4/13 symptomatic). In 17/37 (9/17 symptomatic) with aspecific findings, MRI was inconclusive for the presence of PNS involvement. Symptoms of TB involvement were recorded in 15/37 (40.5%) patients: MRI showed specific findings in 5/37 (all symptomatic) and ruled out lesions in 19/37 (4/19 symptomatic). In 13/37 (6/13 symptomatic) patients with aspecific findings, MRI was inconclusive for TB involvement. Conclusion: MRI may rule in/out PNS involvement in 54.1% of patients. This can be valuable given the low success of nasal mucosa biopsies. Furthermore, when showing inconclusive findings, MRI may indicate the site for a biopsy, thus increasing the rate of success of the procedure. Additionally, in TB (routinely included in axial scans of the PNS), MRI may rule in/out the disease in 64.1% of patients. B-385 14:36 Comparison of duplex sonography and high-resolution MRI in giant cell (temporal) arteritis T.A. Bley1, M. Reinhard2, C. Hauenstein2, M. Markl3, K. Warnatz2, A. Hetzel2, M. Uhl2, M. Langer2; 1Madison, WI/US, 2Freiburg/DE, 3Feiburg/DE ([email protected]) Purpose: Noninvasive diagnosis of giant cell arteritis (GCA) is a challenge. Temporal artery biopsy (TAB) is considered to be the diagnostic gold standard. The purpose of this study was to compare the diagnostic performance of two noninvasive imaging modalities, high-resolution magnetic resonance imaging (MRI) and color-coded duplex sonography (CCDS) in diagnosing GCA. Methods and Materials: The results of MRI studies and CCDS in 59 patients with suspected giant cell arteritis were compared with the final clinical diagnosis (based on the ACR criteria and 6-month follow-up observation). Sensitivity, specificity and positive and negative predictive values (PPV, NPV) were calculated for either method. In 41 of the patients, imaging results were also compared with findings of temporal artery biopsy (TAB). S226 A B C D E F G F H Results: Of the 59 patients, 36 (61%) were finally diagnosed with giant cell arteritis. Sensitivity of MRI (CCDS) was 69% (67%), specificity 91% (91%), NPV 66% (64%) and PPV 92% (92%). TAB was positive in 24 of the 41 biopsied patients (59%). Sensitivity of MRI (CCDS) compared with TAB was 83% (79%), specificity 71% (59%), NPV 80% (73%) and PPV 75% (67%). The differences between MRI and CCDS were not significant. Conclusion: Both noninvasive imaging modalities, CCDS and MRI, have comparably high sensitivities and specificities in the detection of mural inflammatory changes in GCA compared with the final clinical diagnosis and also with the diagnostic gold standard of TAB. Each of the two has its own advantages and disadvantages, which need to be evaluated with regard to the local setting. B-386 14:45 Involvement of the ophthalmic artery in giant cell arteritis visualized by 3 T MRI J. Geiger1, T. NeГџ1, M. Uhl1, W.A. LagrГЁze1, P. Vaith1, M. Langer1, T.A. Bley2; 1 Freiburg/DE, 2Madison, WI/US ([email protected]) Purpose: To retrospectively analyze inflammatory involvement of the ophthalmic arteries in patients with giant cell arteritis (GCA) utilizing high-resolution magnetic resonance imaging. Methods and Materials: A cohort of 50 patients with proven giant cell arteritis (GCA) who had been examined by 1.5 or 3 T high-field MRI was analyzed retrospectively in a consensus reading for possible involvement of the ophthalmic arteries. In 43 patients, entire orbits were within the field of view. In all cases, the superficial cranial arteries displayed mural inflammation in postcontrast-T1 weighted spin-echo (SE) images. MRI results were compared with ophthalmologic findings, subjective visual symptoms and laboratory, i.e. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values. Results: We observed mural contrast enhancement of the ophthalmic arteries in 20/43 patients (46%). Bilateral involvement was seen in 14, unilateral enhancement in six cases. 15 patients had ophthalmic vascular diseases: nine had anterior ischemic optic neuropathy (AION), one posterior ischemic optic neuropathy (PION), four revealed central retinal artery occlusion (CRAO) and one patient presented with narrowing of the retinal arteries. Funduscopy detected no arteritis-related changes in 22 cases. Of those patients who were MRI positive, seven had ophthalmological disease. 26 patients complained of visual symptoms including amaurosis fugax, vision loss, diplopia or eye pain. Conclusion: High-resolution MRI detects mural contrast enhancement consistent with inflammatory changes in the superficial cranial and extracranial arteries and additionally in the ophthalmic arteries. This provides insight in vasculitic orbital involvement during one and the same investigation. B-387 14:54 Color Doppler ultrasound assessment of blood flow velocities changes in the central retinal artery of type 1 diabetic patients submitted to kidneypancreas, kidney-alone and islet-alone transplatation M. Cellina, M. Venturini, C. Losio, P. Maffi, A. Secchi, A. Del Maschio; Milan/IT ([email protected]) Purpose: In long-term type 1 diabetic-uremic kidney-transplanted patients, pancreas or islet transplantation can determine diabetes resolution. Islet-alone (IA) transplantation has been recently introduced for diabetic-non-uremic patients to prevent diabetes-related complications such as retinopathy, characterized by endothelial dysfunction, conditioning a reduction of central retinal artery (CRA) flow velocities. Our aim was to compare CRA velocity changes in kidney-pancreas (KP), kidneyalone (KA) and IA patients after transplant. Methods and Materials: CRA of 10 KP, 10 KA and 10 IA-transplanted patients were evaluated with color Doppler ultrasound (CDU; ATL-HDI5000, 5-12 MHz linear probe) by the same operator before and 2 years after transplantation. Peak systolic (psv) and end diastolic (edv) velocities were measured for each central retinal artery at the retrobulbar level and expressed as the mean of both eyes. Results: All groups showed similar CRA velocities at baseline. At 2 years, the KP and KA groups did not show a significant increase of CRA velocities (KP-psv: 5.73 p 1.75 vs 6.06 p 1.44; KP-edv: 1.68 p 0.31 vs 2.0 p 0.44; KA-psv: 4.55 p 1.42 vs 5.74 p 2.06; KA-edv: 1.68 p 0.54 vs 1.57 p 0.39, P = ns). A statistically significant increase in CRA velocities was found only in IA patients, with significantly higher values than KP and KA (IA-psv: 10.12 p 1.20 vs 6.09 p 0.46, P 0.01; IA-edv: 2.99 p 0.48 vs 1.65 p 0.07, P = 0.02). Conclusion: CDU allows quantitative and reproducible measurements of CRA blood flow velocities. A significant improvement of CRA flow velocities was evident only in IA-transplanted patients and not in KP patients, despite diabetes resolution in both groups. Probably, a reversal of endothelial dysfunction in retinal microcirculation is less likely in patients affected by a longer duration of diabetes, with related uremia and microvascular complications. Scientific Sessions B-388 15:03 Value of apparent diffusion coefficient calculation before and after gustatory stimulation in the diagnosis of acute or chronic parotitis T. Ries, C. Arndt, M. Regier, J. Graessner, M.C. Cramer, M. Jaehne, G. Adam; Hamburg/DE ([email protected]) B-389 15:12 MRI of the parotid gland and duct at 7 Tesla: Better than 1.5 Tesla? O. Kraff, J.M. Theysohn, S. Maderwald, P.C. Kokulinsky, H.H. Quick, Z. Dogan, M.E. Ladd, E.R. Gizewski, S.C. Ladd; Essen/DE ([email protected]) Purpose: To optimize the sequences for high-field MR imaging of the parotid gland and duct at 7T to discuss the potential of high-field imaging in patients. Methods and Materials: A 7T whole-body scanner was used in combination with a 10-cm-diameter loop coil. Various GRE (MEDIC, DESS, 3D-FLASH) and TSE (PD/T2, STIR) sequences were optimized and subsequently tested on 4 healthy volunteers and 12 patients. High-resolution images were compared with 1.5 T images both quantitatively (SNR, CNR) and qualitatively (visual rating of two independent readers). Results: All examinations were completed within 30 min. The high 0.6 mm isotropic resolution of 3D-DESS was very useful to define an oblique orientation with most of the duct being in-plane for subsequent imaging. MEDIC displays very fine branches of the duct; furthermore, MEDIC yields a very good depiction of lymph nodes. Severe SAR problems were observed with the STIR sequence at 7T. Gland tissue in tumor patients can be well characterized with the PD/T2 TSE. Intravenous contrast agent administration in combination with the 3D-FLASH sequence renders even better delineation of various tumor types at 7T. Highest CNR between duct and gland was achieved with the 7T DESS; MEDIC yielded 5.4 times higher CNR at 7T compared to 1.5 T. At 1.5 T, only the STIR sequence showed comparable quality to the overall superior 7T sequences. Conclusion: Within an acceptable time, MR imaging at 7T provides excellent image contrast and resolution of the parotid gland and duct, which is mirrored by the much higher rated image quality. B-390 15:21 Image fusion between EP-DWI and post-gadolinium isotropic 3D VIBE sequences in the head and neck: Feasibility study M. Ravanelli1, D. Farina2, A. Giugno2, R. Monesi2, R. Maroldi2; 1Martinengo/IT, 2 Brescia/IT ([email protected]) Purpose: When examining H&N lesions, the correlation of EP-DW signals with anatomical structures is often a critical issue, given the low spatial resolution and susceptibility artifacts. Therefore, the precise correlation between findings in EP-DWI and conventional high-resolution sequences is mandatory. The fusion of EP-DWI and isotropic 3D GE T1 (VIBE) post-Gd sequences may combine the strengths of both functional and volumetric imaging. Feasibility and accuracy of image fusion is the aim of the study. Methods and Materials: Twenty consecutive patients underwent MR for a primary head and neck neoplasm. MR protocol included EP-DWI and isotropic 3D VIBE sequences. Fusion matching was first performed between b0 and 3D VIBE images; co-registration parameters were then applied to b1000 images; a further tuning 14:00 - 15:30 Room I Physics in Radiology SS 713 Structural and functional imaging Saturday Purpose: To investigate the value of diffusion-weighted (DW) echo-planar imaging (EPI) for quantifying physiological changes of the parotid gland before and after gustatory stimulation in patients suffering from acute or chronic recurrent inflammation in comparison with healthy volunteers. Methods and Materials: Using a DW-EPI sequence at 1.5 T parotid glands of 19 consecutive patients with acute (n = 14) and chronic (n = 5) inflammation of the parotid glands and 52 healthy volunteers were examined. Magnetic-resonance (MR) images were obtained before and after gustatory stimulation with 5 cc of lemon juice. Results: In volunteers, mean ADC values of 1.14 Г— 10-3 mm2/sec before and 1.2 Г— 10-3 mm2/sec after gustatory stimulation were observed. In acute inflammation, ADC values were higher before (1.22 Г— 10-3 mm2/sec (P = 0.006)) and after stimulation [1.32 Г— 10-3 mm2/sec (P 0.001)]. Before stimulation ADC differences between chronic inflammation (1.05 Г— 10-3 mm2/sec) and healthy volunteers (P = 0.04) as well as between acute and chronic inflammation were statistically significant (P = 0.005). No differences were detected after stimulation between chronic inflammation (1.2 Г— 10-3 mm2/sec) and healthy volunteers (P = 0.94) and between acute and chronic inflammation (P = 0.15), respectively. Conclusion: DW-EPI seems to display the physiological changes of the parotid gland in patients suffering from acute or chronic inflammation and might be useful in discriminating healthy from affected glands. was finally performed between b1000 and VIBE images, using as landmarks the hyperintense structures on b1000 images, except tumor. Mismatch between the center of these structures on b1000 and 3D VIBE images was measured in all three major axes using “side by side” visualization modality. Results: Matching between b1000 and 3D VIBE images was performed on 161 anatomical structures (8.5/examination). Mean mismatch on antero-posterior direction (phase-encoding direction) was 1.82 mm (95% CI 0.21 mm); on transversal direction it was 0.74 mm (95% CI 0.08 mm); on cranio-caudal direction it was 0.85 mm (95% CI 0.09 mm). Conclusion: Image fusion between EP-DW and isotropic 3D VIBE sequences is a feasible and accurate technique and may represent an important tool for oncological imaging in the head and neck region. Moderators: T.D. Fryer; Cambridge/UK A. Todd-Pokropek; London/UK B-391 14:00 A step towards perfusion benchmark measurements in clinical imaging devices P. Deman1, T.Y. Lee2, H. Elleaume1, A. Krainik1, J. Le Bas1, F. Esteve1, J. Adam1; 1 Grenoble/FR, 2London, ON/CA ([email protected]) Purpose: New methods aiming to assess quantitative brain perfusion have been developed, based on tracer kinetics models for the extraction of perfusion values. The results vary with the imaging technique, protocols, algorithms and operators. In particular, it is not known to what extent blood brain barrier leakage affects the results. Methods and Materials: As a necessary step towards validating absolute perfusion measurements procedures, we develop a novel method usable with both CT and MRI based on a phantom that mimics perfused tissue under defined conditions. This is a bundle of porous capillaries each about 215 microns in diameter. Theoretical permeability surface (PS), fluid volume and flow are derived from the phantom physical characterization and can be compared with those calculated with the models implemented in workstations. These models have been tested under various input flow rates and sizes of contrast agent. Results: The adiabatic approximation of the Johnson & Wilson model returned the closest fluid flow and volume on a reference scan (17.4p4.5 ml/100 g/min and 21.2p1.5 ml/100 g, respectively) compared to the theory (19.8 ml/100 g/min and 22.9 ml/100 g, respectively). This model was also able to retrieve PS values for two contrast agents' sizes: 7p13 ml/100 g/min for baryum (MicropaqueВ®) and 44p10 ml/100 g/min for iodine (IomeronВ®). The gamma variate model gave relative errors 350% for the smallest contrast agent. Conclusion: To our knowledge, this is the first report of an objective method aiming to validate the CT or MRI perfusion measurement procedures, and shedding the light on controversial absolute perfusion measurements tools. B-392 14:09 Multiple spatial frequency band filtering of whole brain perfusion CT data: Dose reduction and improved spatial resolution E. Klotz1, R. Raupach1, H. Fichte1, B. Schmidt1, T. Flohr1, M. Lell2; 1Forchheim/DE, 2 Erlangen/DE ([email protected]) Purpose: To improve the contrast to noise ratio (CNR) of whole brain perfusion CT scans with the aim to reduce radiation exposure or increase spatial resolution. Methods and Materials: We extended a commercial brain perfusion CT package (Siemens, Germany) equipped with 3D motion correction by a dedicated multiple spatial frequency band filter (MSBF). The filter is applied after motion correction and reduces noise power without impairing the resolution of temporal changes. We retrospectively reconstructed standard whole brain perfusion data (10 cm coverage) of 20 patients with cerebral ischemia or tumors with slice thicknesses between 1.5 and 10 mm. We compared the perfusion parameters calculated from thin slice recons with MSBF with the ones calculated from thick slices without MSBF. Absolute values of CBF, CBV and MTT and their standard deviation in normal and pathological areas were determined to estimate CNR improvement in routine clinical data. A B C D E F G H S227 Scientific Sessions Results: Quantitative perfusion parameters were not significantly different between 1.5 / 3 mm (MSBF) and 6 / 10 mm (no MSBF) slices, respectively. Standard deviation was comparable or smaller. This corresponds to a CNR improvement of about a factor of 2, which can either be used to reduce exposure, slice width or a combination of both without impairing perfusion parameter image quality. Conclusion: The CNR of standard clinical whole brain perfusion CT data acquired with continuous spiral scanning with variable pitch can be significantly improved. MSBF filtering in conjunction with motion correction allows either reducing radiation dose or increasing z-resolution by up to a factor of four. B-393 14:18 Colour CT X-ray spectroscopic images of mice using Medipix-2 detector N.G. Anderson1, A.P. Butler1, N. Scott1, N.J. Cook1, J. Butzer1, N. Schleich1, M. Firsching2, P.H. Butler1; 1Christchurch/NZ, 2Erlangen/DE ([email protected]) Purpose: In the future, X-ray biomedical imaging will combine spectroscopic with spatial and temporal and density information to allow tissue characterisation and quantification in 3D image using one X-ray source. The aim of our study was to produce 3D spectroscopic images of a mouse using a Medipix-2 detector. Methods and Materials: We have built a desktop X-ray spectroscopic CT scanner using the Medipix-2 detector (MARS). We imaged six mice, mean weight 30 g (range 27-34 g). The mice were lethally anaesthetised with pentobarbitone at the time of injecting contrast agent directly into the heart (0.5 mL) or pleural space (0.5 mL) or bronchial tree (0.2 mL). Barium sulphate and Lipiodol were used. The dead mice were preserved in resin then imaged in the scanner at 75 keV; tube current was nominally 0.079 mA. Results: We were able to discriminate the different contrast agents in the bronchial and vascular tree with high resolution, displaying calcium and iodine as different colours on the same image. We could discriminate the vascular anatomy of the mouse kidney down to interlobar vessels spatially (0.055 mm) and spectroscopically. Calcium was differentiated from contrast. Excellent soft tissue contrast was achieved. Multiple images will be shown to demonstrate this. We expect to differentiate barium and iodine shortly. Conclusion: Our novel X-ray spectroscopic scanner provides 3D spectroscopic images of the mouse that can distinguish calcium and different contrast agents within adjacent very small vessels at low radiation dose. This has wide potential for human imaging including vascular imaging, detecting microcalcifications, tissue characterisation and quantification. B-394 14:27 Automatic intrinsic method for combined respiratory and cardiac gating in small animal cone-beam CT J. Kuntz1, J. Dinkel1, S. Zwick1, M. Grasruck2, F. Kiessling3, W. Semmler1, S.H. Bartling1; 1Heidelberg/DE, 2Forchheim/DE, 3Aachen/DE ([email protected]) Purpose: To develop a retrospective projection-based method for completely automatic intrinsic respiratory and cardiac gating, to reduce the complexity of scanning processes and the influence of potential external interferences. Methods and Material: Projection data of both mice (10) and rats (10) were acquired using a prototype flat-panel cone-beam CT system. To extract the gating signals out of the projection data, a region of interest (ROI) was placed to cover diaphragm and heart. The diaphragm was found by detecting the maxima in difference images of projections from several rotations at same or similar angular positions. Within this ROI the center of mass was calculated and plotted over projection positions. After band-pass filtering with appropriate cardiac and respiratory frequencies resorting of the projection data was performed with respect to the gating signal. This resulted in a phase-sensitive reconstruction. To evaluate the developed method, intrinsic data (image quality, functional parameters and gating signals) were compared with a simultaneously acquired extrinsic gating gold-standard. Results: Automatic, intrinsic gating worked reliable in all cases. Gating signals of automatic intrinsic and extrinsic gating correlated well. Image quality and functional parameters were equivalent using both gating methods. High-quality reconstruction of 4D cine series was possible. Conclusion: The developed method enables a fully automatic cine reconstruction of animals’ respiration and cardiac motion only from projection data itself. It is scanner independent and can be ported to other cone beam scanner systems, making external gating hardware or manual interaction superfluous. S228 A B C D E F G F H B-395 14:36 Quantitative tissue characterisation in dual energy computed tomography J.K. Van Abbema, M.J.W. Greuter, W. Kristanto, M. Oudkerk; Groningen/NL ([email protected]) Purpose: Validation of a model for quantitative tissue characterization by assessment of effective atomic numbers and electron densities from tomographic reconstructions of dual energy CT (DECT). Methods and Materials: A model was developed using a parameterization of the linear attenuation coefficient. The model can be used to calculate the effective atomic number and electron density based on CT numbers from DECT images. The model was validated for 16 chemical substances (effective atomic numbers ranging from 5.47 to 12.96 and electron densities ranging from 2.20 to 4.12 Г— 1023 electrons/cm3) by combining 80 kV and 140 kV data sets from a dual source CT. Results: The calculated effective atomic numbers for the 16 substances correlated well with the actual effective atomic numbers (Pearson’s chi-square value of 0.55, deviation -10.8 to 9.3%). The calculated effective electron densities correlated very well with the actual effective electron densities (Pearson’s chi-square value of 0.005, deviation -1.6 to 2.5%). Conclusion: The proposed model can be used as a quantitative tool for tissue characterization in DECT. B-396 14:45 Dedicated phase-correlated small animal micro-CT imaging D. Ertel, Y. Kyriakou, M. Mronz, R.M. Lapp, W.A. Kalender; Erlangen/DE ([email protected]) Purpose: To validate the performance of a phase-correlated image reconstruction procedure with respiratory gating for small animal micro-CT imaging. Methods and Materials: Small animal imaging using micro-CT systems provides high spatial resolution, but often suffers from motion artifacts due to respiratory motion. External synchronization signals are not always available and a phasecorrelated reconstruction cannot be performed. We generate a dedicated synchronization signal using a raw data-based motion function (kymogram) correlating with the respiratory motion, based on a center-of-mass tracking on the flat panel detector. Ten measurements of free breathing rodents were performed on a dualsource micro-CT scanner (Tomoscope 30s Duo, VAMP GmbH, Erlangen, Germany). Projection data were acquired over ten rotations for multi-segment phase-correlated reconstruction, i.e. using projection data of the same respiratory phase covering a complete rotation for image reconstruction. Motion artifacts in the phase-correlated images were analyzed to evaluate the reliability of our method. Results: The kymogram approach provided a reliable synchronization signal correlating with the respiratory motion cycle. Phase-correlated images showed an improved image quality, above all in the diaphragm region, with respect to motion artifacts. Here, object resolution was increased due to reduced smearing artifacts. Image noise was increased typically by a factor of three, which was in good agreement with the quadratic dependence on the number of rotations. There was a reduction in data from ten rotations down to a single one. Conclusion: We conclude that kymogram-based small animal CT imaging is feasible with micro-CT. Ways to reduce the number of rotations are under investigation. B-397 14:54 X-ray phase contrast imaging: Visualization of architectural properties of human articular cartilage P. Coan1, A. Bravin1, E. Muetzel2, D. Habs3, M.F. Reiser2, C. Glaser2; 1Grenoble/FR, 2 Munich/DE, 3Garching/DE ([email protected]) Purpose: Identification of fine structural details and disruption in collagenous fibre architecture within cartilage is important to diagnose early osteoarthritis (OA). Thus, high-resolution imaging allowing for three-dimensional analysis of tissue structure is desirable. Over the last decades, X-ray phase contrast (PhC) imaging has been introduced as an alternative radiographic approach to yield a markedly stronger contrast than absorption radiography. The aim of our study was to apply X-ray PhC imaging for the characterization of architectural properties of intact and pathological cartilage. Methods and Materials: Three healthy and one pathological cartilage on bone cylinders from 4 human patellae have been imaged using the analyzer-based (ABI) and the propagation-based (PBI) PhC imaging techniques. Both projection and computed tomographic images at high resolution (25 keV, digital Frelon camera, voxel size: 8Ві and 46Ві micronВі) have been acquired and compared with scanning electron microscopy of the same samples. Scientific Sessions Results: Phase contrast projections and CT showed excellent depiction of the architecture of subchondral bone in both ABI and PBI modes. A zonal pattern within the cartilage matrix similar to collagenous fibre orientation in SEM could be visualized. Conclusion: High resolution PhC imaging is able to reveal structural details in cartilage tissues suggesting a high potential of phase contrast imaging for future diagnostic workup of OA. B-398 15:03 Evaluation of cross-scatter effects on rawdata-based tissue decomposition in dual energy dual source CT (DE-DSCT) M. Meyer, Y. Kyriakou, W.A. Kalender; Erlangen/DE ([email protected]) B-399 15:12 Removal of arterial wall calcifications in CT angiography using calciumiodine spectral decomposition with simultaneous multi-energy MDCT A. Vlassenbroek1, G. Kafri2, Y. Bar2, L. Goshen2, P. Coulon3; 1Brussels/BE, 2Haifa/IL, 3 Paris/FR ([email protected]) Purpose: Arterial wall calcifications may hinder the visualization of the arterial lumen in CT angiography. Our purpose was to demonstrate that iodine-selective images obtained with simultaneous multi-energy MDCT may enable a better visualization of the arterial lumen. Methods and Materials: A phantom was constructed in lucite with 3 cylindrical holes representing arteries of various diameters and including hyperdense tubes made of polyvinylchloride mimicking calcified plaques all around the vessel wall. This phantom was filled with increasing concentrations of iodine and imaged on a prototype of a multi-energy MDCT scanner (Philips Healthcare). Simultaneously acquired data from 2 layers of detectors were reconstructed to reflect low energy and higher energy attenuation from a single X-ray source. Iodine-selective images were used after material separation to measure the lumen sizes and to compare them to the known lumen sizes. Results: All measurements performed from the CT images after removal of the high density structures by thresholding showed a threshold- and concentrationdependent underestimation of the lumen size up to 100%. However an excellent correlation was found between the lumen sizes measured from the iodine-selective images at all iodine concentrations and the known lumen sizes (R 0.98), with an underestimation less than 10%. Conclusion: Our results suggest that iodine-selective images provided by multienergy CT enables an accurate visualization of the residual arterial lumen,which would be otherwise hindered by the blooming of calcified lesions in the regular CT image. This method is less subjective and more accurate than calcification removal by thresholding. 15:21 Detection of occluded lung vessels using dual energy CT: A phantom study B. Krauss1, K. Otani2, B. Schmidt1, T. Flohr1; 1Forchheim/DE, 2Tokyo/JP Purpose: To study whether dual energy CT can aid in the detection of PE in small, peripheral vessels and to investigate the impact of motion. Methods and Materials: The SOMATOM Definition (Siemens Healthcare, Forchheim, Germany) can be used for dual energy CT scans of the lung (14 x 1.2 mm, 0.33 s rotation time, 140 kV/80 kV, 50 mAs/213 mAs, pitch 0.5) in order to show the iodine/blood ratio for vessels. Plastic tubes simulating lung vessels (0.75-5 mm diameter) were mounted inside an anthropomorphic thorax phantom (QRM, MГ¶hrendorf, Germany) and filled with water (occluded vessel) or iodine solution (5 ml Iopromide 300 per 100 ml; 618.7 HU / 329.0 HU at 80 kV/140 kV). Images were evaluated with syngo dual energy (Siemens Healthcare). A QRM motion phantom provided continuous vessel motion with 8.3 mm/s or heart motion (60 bpm, amplitude 2 cm). For each scan, two reconstructions were performed (kernels D30f / B70f). Results: CT-values in the weighted average images and dual energy evaluation could distinguish water and iodine for 3 mm diameter. For 1.5 mm (water) and 1.0 mm (iodine) maximum CT-values in the axial slices were below -100 HU (B35f) and above 500 HU (B70f), but dual energy could detect water down to 1 mm and iodine down to 0.75 mm without errors. For continuous motion, water (1.5 mm) and iodine (1 mm) were only distinguishable with dual energy; for heart motion, iodine (5 mm) could be detected. Conclusion: Dual energy scanning allows to assess the iodine content of small lung vessels for which single energy CT-values are not conclusive; for the same scan, dual energy evaluation is less sensitive to motion than CT-value-based diagnosis. 14:00 - 15:30 Room K Pediatric SS 712 Cardiothoracic Moderators: K. Foster; Birmingham/UK D. Prayer; Vienna/AT B-401 14:00 Low-dose ECG-gated DSCT angiography: Preoperative assessment of complicated congenital heart disease X.M. Wang, Z.P. Cheng, L.B. Wu, D.W. Wu, Y.H. Duan, B.T. Chao, C. Liu; Ji Nan/CN ([email protected]) Purpose:This study was performed to investigate the clinical value of low-dose ECG-gated DSCT angiography in preoperative assessment of complicated congenital heart disease. Methods and Materials: A total of 51 patients (mean age 3.2 p 2.56 years, range: 2 months-15years; male 28) with suspected complicated congenital heart disease underwent both ECG-gated DSCT angiography and color Doppler echocardiography (CDE). Individual low-dose ECG-gated DSCT scan parameters were used according to the patient’s weight. In addition to the CT axial slices, 3D reconstructions such as volume rendering (VR) and multiple planar reformation (MIP) were used to diagnose cardiac abnormalities. The results were compared based on the results of surgical findings. Statistical analysis was performed to compare the ability of the two modalities to evaluate the anomalies of major structures. Results: A total of 182 cardiac deformities were confirmed by operations. The accuracy of DSCT and CDE in the diagnosis of incardiac deformities (63) were respectively 95.2 and 98.4%. DSCT was as accurate as CDE in revealing incardiac deformities (C2 = 1.033, P 0.10). The accuracy of DSCT and CDE in extracardiac deformities (119) were respectively 99.2 and 67.2%. DSCT was superior to CDE in extracardiac deformities (C2 = 43.393, P 0.005). The mean CTDIvol of all patients was 5.88 p 3.35 mGy. Conclusion: Low-dose ECG-gated DSCT angiography was more sensitive in evaluating the anomalies of systemic vessels, pulmonary vessels and coronary artery. It is extremely valuable in planning operative procedures, especially in patients with complicated congenital heart disease. A B C D E F G H S229 Saturday Purpose: To evaluate the impact of cross-scatter between both systems in DEDSCT and to develop a correction algorithm to improve the accuracy of a dedicated off-line raw-data based on the material decomposition. Methods and Materials: Measurements were carried out at tube voltages of 140 and 80 kV on a Siemens SOMATOM Definition DSCT scanner. Cross-scatter was measured by turning one tube off and reading out the corresponding detector. Measurements were performed at mAs-ratios (ratio of low-energy mAs to highenergy mAs settings) ranging from 1 to 4. The cross-scatter correction algorithm uses raw-data based on the object size estimations and look-up tables generated by measurements of tissue-equivalent reference phantoms with varying size and tube voltage. We evaluated the image quality of the CT images. For anthropomorphic phantoms, material density images for water and calcium with and without the cross-scatter correction have been compared using two separate single source scans as a reference. Results: The distribution of cross-scatter intensity and corresponding artefacts depended on the phantom dimensions and on the mAs-ratios. Scans at an mAsratio of 1 did not yield meaningful results. An mAs-ratio of 4 led to images with an average deviation of water and calcium density values of up to 100% for a 30 x 40 cmВІ thorax phantom. Cross-scatter correction decreased the error down typically to 25 and 15% for mAs-ratios of 1 and 4, respectively. Conclusion: Cross-scatter may cause substantial artefacts and errors in the calculation of material-selective images, but can be corrected to a large degree. B-400 Scientific Sessions B-402 14:09 Usefulness of 64-slice MDCT angiography for evaluating aortopulmonary collateral arteries with complex pulmonary stenosis or atresia in children Y. Peng, J. Li; Beijing/CN ([email protected]) Purpose: To evaluate the aortopulmonary collateral (APC) arteries with complex pulmonary stenosis or atresia in children with 64-slice CT angiography (CTA). Methods and Materials: A total of 28 children (16 boys, age 28 days to 8 years) with pulmonary stenosis or atresia underwent 64-slice CT angiography. Diagnoses included tetralogy of Fallot (TOF) with pulmonary atresia (n = 6) or pulmonary stenosis (n = 4), post-Fontan palliation (n = 4), PA-VSD (n = 6), right pulmonary artery absence (n = 3) and other complex congenital heart diseases (n = 5). Two independent radiologists analyzed the numbers, origins, courses and the diameters of APC arteries and the lung areas they supply. The results are compared with those of cardiac catheterization (n = 15) using Bland-Altman analysis. Results: CTA found 68 APC arteries, and 64 were confirmed by either surgical procedure or catheterization. Four additional APCs were diagnosed by CTA, but not by surgical procedure (n = 2) or catheterization (n = 2). CTA had a 100% sensibility and specificity for the diagnosis of main (n = 9) and branch pulmonary artery stenosis or hypoplasia (n=21), as well as absent (n = 3) or discontinuous (n = 2) branch PAs. Major APC arteries supplied the pulmonary circulation wholly in ten patients. The CT measurements showed excellent inter-observer and intra-observer reliability with coefficients of 0.91and 0.93, respectively. There were good correlation in diameter measurements between CT and catheterization with correlation coefficient of r = 0.816. Conclusion: CT angiography is an accurate, noninvasive alternative to surgical procedure or catheterization for evaluating the characteristics of aortopulmonary collateral arteries in children with complex pulmonary stenosis or atresia. B-403 14:18 Sixty-four-row MDCT in neonates with complex congenital heart disease: Preliminary experience M. Ulla, J.L. Savluk, E. Levy, M. Vazquez-Durand, J. Makarovsky, R. Garcia-MГіnaco; Buenos Aires/AR ([email protected]) Purpose:To evaluate the clinical feasibility of 64-row MDCT in replacing diagnostic cardiac catheterization (CC) in a consecutive series of neonates (less than 30 days old) with complex congenital heart disease. To demonstrate the utility of 64-row MDCT for anatomical delineation and pre-surgical evaluation. Methods and Materials: Over a 1-year period, nine neonates (mean age = 7 days) with complex congenital heart disease (more than one separate cardiovascular anomaly) were prospectively scanned. In these patients, the diagnostic confidence of echocardiography was low. A 64-row CT scan was performed in each neonate with intravenous injection of diluted non-ionic iodinated contrast medium (2 ml/kg) and injected with dual syringe injection. A multidisciplinary congenital heart disease team evaluated the images and decided if diagnostic CC was necessary before surgery. The mean scanning time was 5 seconds and the mean radiation dose 1.7 mSv. The diagnostic accuracy of 64-row MDCT was compared with surgical findings and final clinical diagnosis. Results: No diagnostic CC was needed in any neonate prior to the surgery. In all cases, cardiovascular anatomy and relationship between adjacent structures could be accurately assessed for the presurgical evaluation. Sedation times were minimized (average 10 minutes), reducing potential complications in this population in comparison with CC. Conclusion: In this preliminary series, 64-MDCT showed clinical feasibility of replacing diagnostic CC in complex congenital heart disease of neonates. It proved to be useful in cardiovascular anatomy delineation and achieved diagnosis in a quick and non-invasive way. Further studies must be performed to validate this experience. B-404 14:27 Usefulness of the ECG-gated dual source CT for evaluating the configuration of the coronary arteries in patients with congenital heart disease M. Nakagawa, M. Hara, K. Sakurai, Y. Ozawa, T. Kawai, S. Yuta; Nagoya/JP ([email protected]) Purpose: To evaluate how precisely ECG-gated DSCT can depict the configuration of the coronary arteries (CAs) in children with congenital heart disease (CHD). Methods and Materials: Between August 2006 and August 2008, 31 patients with CHD (aged 1 day to 9 years, median age 11 months; body weight 2.3-17.0 kg, median 6.7 kg) were examined using DSCT (SOMATOM Definition; Siemens) with ECG gating and without breath holding. Mean heart rates were between 80 and S230 A B C D E F G F H 150 bpm (median 124). The parameters of DSCT scan were 80-200 mAs, 120 kV, 0.75 mm slice thickness, 50% overlap and the time resolution was 83 msec. Nonionic contrast medium (300 mgI/mL, 2 mL/kg) was administrated using a power injector. The degree of visualization of the CAs was graded as follows: grade 0, no CAs were depicted at all; grade 1, only origins of the CAs were depicted; grade 2, useful for diagnosing the abnormality of the CAs with mild motion artifacts; grade 3, excellent for diagnosing the abnormality of the CAs. The degree of visualization was determined by consensus of two radiologists. Results: Of the 31 patients with CHD, visual evaluation of the CAs was graded as 0 in 3 (10%), 1 in 5 (16%), 2 in 9 (29%) and 3 in 14 (45%) cases. All patients with grade 0 or 1 visualization were younger than 2 months. Conclusion: We suggest that DSCT with ECG gating is a useful technique for evaluating the coronary artery of patients with various CHD older than 2 months. B-405 14:36 Value of MDCT volume-rendered images in evaluation of children with persistent respiratory symptoms due to vascular ring anomalies Y. Peng, J. Li; Beijing/CN ([email protected]) Purpose: To investigate the usefulness of MDCT volume-rendered (VR) images in evaluating the relationship between cardiovascular structures and the airway in children with persistent respiratory symptoms duo to vascular rings. Methods and Materials: We retrospectively reviewed the MDCT VR images of 26 children (20 boys, ages 4 days to 4 years) with suspected vascular ring contributing to persistent respiratory symptoms. The VR views of cardiovascular structures and the вЂ�transparent’ VR view of airways were reconstructed and composed to show their relationship. Results: The morphology and topography of the vascular anomalies and their relation to adjacent tracheal ompression structures were assessed accurately by the composite VR images, and imaging findings correlated well with intra-operative findings and clinical diagnosis. Vascular rings were confirmed and included cases of five complete and three incomplete double aortic arch; three right arch left ligamentum; two innominate artery compression; threee (two) aberrant right (left) subclavian artery; eight pulmonary artery sling. Stenoses were seen in the trachea of 14 patients and isolated main bronchus obstruction was present in 3 patients. Eight patients had compression of trachea, tracheal carinal and a main bronchus; five of them had secondary long-segment tracheomalacia. Associated cardiac anomalies and trachobranchus malformation were present in 31% (8/26) and 23% (6/26) of the patients, respectively. Conclusion: Composite MDCT VR images are reliable for demonstrating the morphology and topography of vascular anomalies in relation to adjacent tracheobronchial tree compression structures in children with vascular rings, and can provide more accurate evaluation for operation and anesthesia. B-406 14:45 Mid-term follow-up after arterial switch operation for complete transposition of the great arteries S. Ley1, J. Ley-Zaporozhan1, M. Gorenflo1, T. Loukanov1, C. Sebening1, S. Hagl1, H.E. Ulmer1, H.-U. Kauczor1, R. Arnold2; 1Heidelberg/DE, 2Freiburg/DE ([email protected]) Purpose: Transposition of the great arteries has to be surgically corrected by an arterial switch operation. This complex surgical procedure has the potential for significant short- and long-term complications like dilation of the neo-aortic root, coronary and pulmonary artery (PA) stenosis. The aim was to determine a suitable follow-up algorithm for mid-term follow-up. Methods and Materials: 26 patients (mean age 10p2 years) were examined using echocardiography, ECG-gated CTA and functional MRI (flow and cine measurements, pulmonary perfusion). Results: CTA was capable of visualizing coronary arteries in all cases. Coronary stenosis did not occur. Echocardiography failed to visualize the coronary arteries in 81%. CTA showed that 41% of the PAs had moderate stenosis (25-50% lumen reduction) and 10% had severe stenosis ( 50%). Visualization of pulmonary arteries was not possible by echocardiography in 55%. No correlation between MR-perfusion abnormalities and PA stenosis was found. In echocardiography, 4 patients showed a mild stenosis of the main PA (mean pressure gradient 34 mmHg) while MRI found an increased velocity, suggestive for a stenosis, in 9 patients. 10 patients showed a neo-aortic root dilatation. In echocardiography, 8 patients had mild, 4 had moderate aortic valve insufficiency. Aortic valve insufficiency was too small to be quantified by MRI. Conclusion: Stenosis of the PA was seen in a significant number of patients and the leading complication after surgery. Echocardiography should be recommended for the assessment of cardiac function, CTA for morphology of coronary arteries and PA. The value of MRI for assessment of functional parameters is limited. Scientific Sessions B-407 14:54 Contrast-enhanced cardiac magnetic resonance imaging in children and adolescents with clinically suspected myocarditis D. Honnef, H.H. HГ¶vels-GГјrich, D. Gkalpakiotis, H. KГјhl, M. Neizel, N. KrГ¤mer, C.A. Schwartz, R.W. GГјnther, G.A. Krombach; Aachen/DE ([email protected]) B-408 15:03 Comparative evaluation of chest radiography, low field MRI, the Shwachman-Kulczycki score and pulmonary function tests in patients with cystic fibrosis A. Anjorin1, H. Schmidt2, H.-G. Posselt2, T.J. Vogl2, N. Abolmaali3; 1Basle/CH, 2 Frankfurt a. Main/DE, 3Dresden/DE ([email protected]) Purpose: To evaluate comparability of Chrispin-Norman-Scores (CN) in patients with cystic fibrosis (CF) determined with conventional chest radiography (CXR) and fast low-field MR-imaging (MR) of the lung parenchyma. Methods and Materials: 73 patients (age 7-32 years, median 14) with CF received their annual CXR and additional MR at 0.2 T (Magnetom Open Viva, Siemens). Thorax imaging using the breath-hold CISS-sequences (TR/TE=6.17/2.97 ms, SL=20 mm). In consensus reading, two pediatric radiologists with expertise in CF analyzed CXR and MR using the CN-Scoring system. Results: The meanpstandard deviation CN-score from MR was 12.0p4.5 with a higher score than CXR in 23 patients (31.5%). The CN-score from CXR was 12.1p4.7 with a higher score than MR in 25 patients (34.3%). The difference between the two scores was 0.12 and was not significant. There was a significant correlation between both scores for all matched pairs (p 0.05, r=0.97). CXR and MR-CN-scores correlated better with the measured FEV1 (p 0.001, r=- 0.65) und (p 0.001, r=-0.65), respectively, than with FVC (p 0.001, r=-0.46) and (p 0.001, r=-0.47). Both scores correlated to some degree with the Schwachman-Kulczycki scores (p 0.001, r=-0.52 for CXR and r=-0.53 for MR). Conclusion: CN-scoring of CF is possible with fast low-field MR. Since scoring differences between CXR and MR are not significant, further research is strongly suggested to reduce radiation exposure in patients with CF in long term follow-up, especially in children with minor pulmonary involvement. In these cases the correlation of the clinical scores are poor, whereas the correlation of the imaging scores are high. B-409 15:12 Assessment of asymptomatic cystic fibrosis patients with normal lung function tests, but chronic pseudomonas colonisation, using low-dose HRCT O.J. O’Connor, K. O’Regan, S. McSweeney, M. Vandeleur, A. McGarigle, M. O’Neill, M. Ni Chronin, M. Maher; Cork/IE ([email protected]) Purpose: In cystic fibrosis (CF), pulmonary function tests (PFTs) and conventional radiography (CR) are used to monitor disease. HRCT surpasses CR in detecting mucous plugging, which precedes pseudomonas colonization and bronchiectasis, often prior to PFT disturbance. Radiation doses are of particular concern in CF pa- B-410 15:21 Lung development in congenital diaphragmatic hernia: Is the contralateral lung normal? C. Balassy, G. Kasprian, P.C. Brugger, B. Csapo, C.J. Herold, D. Prayer; Vienna/AT ([email protected]) Purpose: CDH is associated with severe hypoplasia of the ipsilateral lung. The purpose of this study is to assess the developmental changes of the apparently not affected contralateral lung, using signal intensity ratios (SIR) and lung volumes. Methods and Materials: A total of 16 fetuses (22-27 weeks of gestation) were examined with a 1.5 T unit. Mean SIs for lungs and liver were assessed on T1-weighted and T2-weighted sequences, and then the lung/liver signal intensity ratios (LLSIR) were calculated. These parameters, together with lung volumes, were compared to an age-matched control group of 115 fetuses using t-test and U-test. Further, SIRs and lung volumes were correlated with neonatal outcomes. Results: Mean SIs of the lungs and LLSIRs in fetuses with CDH were significantly higher in both lungs on T1-weighted images, compared to the normal group (P 0.001 and P = 0.029, respectively). On T2w imaging, mean lung SIs, but not the LLSIR, were increased in both lungs in CDH, compared to the age-matched controls (P 0.001). Total lung volumes were significantly smaller in the CDH group than in the controls (P 0.001). The outcomes correlated significantly with total lung volumes, but not with signal intensity changes in the lungs. Conclusion: The significantly greater increase of lung SIs and LLSIR on T1w imaging in CDH can be explained by the relatively higher proportion of lung parenchyma also in the contralateral lungs, compared to normal fetuses. The SI increase on T2-weighted images is presumably caused by the accumulation of concentrated alveolar fluid with elevated protein content in both lungs. 14:00 - 15:30 Room L/M Vascular SS 715 Therapy evaluation Moderators: A.L.J. Bojanovic; Nis/RS J. Kettenbach; Vienna/AT B-411 14:00 Dual-source CT in abdominal aortic aneurysm treated with endovascular repair: Is dual energy imaging effective for endoleak detection? P. Stolzmann1, T. Frauenfelder1, T. Pfammatter1, H. Scheffel1, M. Lachat1, B. Schmidt2, B. Marincek1, H. Alkadhi1, T. Schertler1; 1Zurich/CH, 2Forchheim/DE ([email protected]) Purpose: To investigate the diagnostic accuracy of dual energy dual source computed tomography (DSCT) for the detection of endoleaks after endovascular repair (EVR). Methods and Materials: After EVR, 118 patients (21 females, 74p9 years) underwent follow-up DSCT including non-enhanced, arterial, and delayed-phase acquisitions. The delayed-phase data was acquired using the dual energy tech- A B C D E F G H S231 Saturday Purpose: Late enhancement in myocarditis is well known in adults, but so far not systematically assessed in children and adolescents. Consequently, the aim of our study was to evaluate contrast-enhanced MRI in children and adolescents with clinically suspected myocarditis. Methods and Material: Between 2003 and 2008, 22 patients (5-24 years, mean 16.5 years; 17 male) with clinically suspected myocarditis due to clinical presentation were examined on a 1.5 T MRI scanner with a synergy cardiac coil. The following ECG-triggered sequences were evaluated: cine-balanced FFE; T2-TSE-STIR and T1w-GRE with inversion pulse after contrast media application. We assessed wall motion abnormalities, edema, late enhancement and pericardial effusion. Results: Abnormalities on delayed contrast-enhanced MRI were found in 12/22 patients. Late enhancement was mainly midwall/subepicardial (n = 11) and less frequently transmural (n = 1). Eleven patients had corresponding edema. In one patient, T2-TSE-STIR was not available. Using the 17-segment model, 6.3 p 3.0 segments were involved per patient. The lateral left ventricular wall was affected with 52.7% (septal 19.4%, anterior 18.1%, inferior 9.7%) of 72 enhancing segments. The distribution of the left lateral ventricular wall was as follows: basal 47.4%, midcavity 36.8% and apical 15.7%. The inferolateral basis was most often involved (10/72). Pericardial effusion was found in eight patients. Wall motion abnormalities were assessed in five patients. Conclusion: In our group of patients, contrast-enhanced MRI reliably demonstrated the presence of myocarditis. In children and adolescents with clinically suspected myocarditis, contrast-enhanced MRI can demonstrate the myocardial extent of inflammation, wall movement abnormalities as well as concomitant pericardial effusion. tients (young patient, chronic, progressive disease). This study aimed to assess the performance of low-dose HRCT in place of CR in CF patients with normal PFTs. Methods and Materials: Following ethical approval, eight CF and five non-CF patients underwent low-dose HRCT examinations. Six 1 mm slices were acquired at 120 kV, 30-50 mAs and 0.5 sec rotation time. The Bhalla HRCT scoring system was used to assess disease severity. Image quality and noise were analysed subjectively and objectively. Effective radiation doses were calculated for each HRCT. Results: Disease severity was mild in the CF group (mean age: 14 yrs) with an average Bhalla score of 7.0/25 (range 1-13). Of eight CF patients, seven had mild bronchiectasis in more than nine segments. Non-CF patients (mean age: 13 yrs) had minor parenchymal and airway changes with a significantly lower (P = 0.01) average Bhalla score (0.2/25). Image quality was highly acceptable with an average attenuation value standard deviation of 16 HU. The average effective dose was 0.17 mSv per HRCT for both groups. Conclusion: Despite normal PFTs, a large proportion of CF patients had bronchiectasis and consolidation. This study demonstrates that low-dose HRCT can detect important findings at effective doses comparable with CR (PA and lat), with acceptable image quality. Thus, low-dose HRCT can potentially improve the management of CF patients and selected subgroups of non-CF patients with pulmonary symptoms. Scientific Sessions nique enabling the reconstruction of virtual non-enhanced images. Two blinded and independent readers evaluated the data for the presence or absence of endoleaks in three reading sessions: standard non-enhanced, arterial, and delayed-phase (session A); virtual non-enhanced, arterial, and delayed-phase (session B); virtual non-enhanced and delayed-phase (session C). Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were calculated with session A as the reference standard. Radiation dose parameters were estimated. Results: Session A revealed 52 endoleaks in 118 patients (44%). The diagnostic accuracy of reading sessions B and C were identical; sensitivity, specificity, NPV, and PPV were 100, 97, 100, and 96%. The accuracy of sessions B and C were not significantly different when compared to session A (P=.50). The effective dose of protocol C was significantly (P .001) lower than that of a standard triple-phase protocol (mean difference: 61%) and to that of a protocol including a standard non-enhanced and a delayed phase (mean difference: 41%). Conclusion: A single dual energy DSCT scan in the delayed-phase allows for the accurate diagnosis of endoleaks after EVR of abdominal aortic aneurysms and reduces the radiation exposure by omitting non-enhanced acquisitions by virtual non-enhanced images. B-412 14:09 Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm treated with endovascular repair (EVAR): A preliminary experience R. Iezzi, A. Giammarino, D. Giancristofaro, D. Gabrielli, A. Cotroneo, M. Storto; Chieti/IT ([email protected]) Purpose: To define the real influence of radiation dose on diagnostic accuracy of CT scans in the follow-up of patients who underwent EVAR. Methods and Materials: 30 consecutive adult patients (29 M, 1 F; mean age: 76.7p6 years; age range: 70-87 years) who had to be undergone 1- or 6-month follow-up MDCT of the abdominal aorta as part of routine post-EVAR surveillance (mean follow-up 8.9 months) were prospectively enrolled in our study. Two consecutive CT scans were considered: at IВ° control CT exams were acquired using the standard acquisition protocol (130 mAs/120 kV) whereas at IIВ° control a low-dose scanning technique (100 mAs/80 kV) was used. Axial and 3D-images were independently evaluated by two blinded radiologists quantitatively (maximum arterial enhancement, contrast-to-noise (C/N) rates), and qualitatively (technical adequacy, image quality, and image noise). Quantitative and qualitative results were statistically compared. Dose reduction was also evaluated. Results: No statistically significant differences were found between the two protocols in terms of CNR (14.22p7.1 vs 11.44p7.8; p=0.17). The subjective qualitative assessment of quality performed on axial images revealed statistically higher values for the standard protocol rather than low-dose protocol in all segments evaluated (p 0.001). On the other hand, no statistically significant differences were found between the two groups in terms of subjective qualitative assessment of quality performed on 3D images. An overall dose reduction as high as 74% was observed for low-dose protocol. Conclusion: In the post-EVAR CTA follow-up, it could be possible to reduce X-ray exposure acquisition dose with no loss in image quality. B-413 14:18 Dynamic CT-angiography in the diagnosis of aortic dissection and endoleaks after endovascular repair of aortic aneurysms W.H. Sommer, A. Graser, A. Helck, D.-A. Clevert, K. Nikolaou, M.F. Reiser, T.R.C. Johnson, C.R. Becker; Munich/DE ([email protected]) Purpose: To assess the diagnostic accuracy of time-resolved CT-angiography (TR-CTA) in aortic pathologies, in particular aortic dissection and endoleaks, after endovascular repair. Methods and Materials: Thirty-one patients with suspected endoleak or dissection underwent TR-CTA of the aorta using a 128-slice CT-scanner with continuous bidirectional table-movement for time-resolved imaging. 12 phases covering the aortic stent/dissection were acquired (acquisition time: 2.5 s per phase, 30 s total; scan range: 27 cm; Ultravist 370, BayerSchering). Tube potential and current were lowered to 80 kV and 120 mAs, in order to decrease radiation exposure. Timepoints of initial and maximum-contrast enhancement were determined for: (a) true and false lumen in patients with dissection and (b) for endoleak and the stent-lumen in patients with endoleaks. The effective radiation exposure for TR-CTA was calculated. Results: Seven aortic dissections and 9 endoleaks were observed. In patients with dissection, maximum contrast enhancement occurred earlier in the true than in the false lumen (17.8 vs. 20.7 s; p 0.01). In patients with endoleaks, inital and maximum contrast-enhancement were significantly delayed in the endoleak as compared to the stent-lumen (initial-enhancement, 4.7 vs. 9.4 s; p 0.01; S232 A B C D E F G F H maximum-enhancement, 15.0 vs 20.0 s; p 0.01). Mean effective radiation exposure was 14.6 mSv. Conclusion: The current TR-CTA-protocol of the aorta is a promising new application to differentiate true and false lumen in aortic dissection and to assess dynamic information of blood flow in patients with endoleak. This additional information is important for the management of those pathologies and may be obtained with comparable dose as compared to a standard two- or three-phase CTA-protocol. B-414 14:27 Non-contrast volumetric CT for follow-up of endovascular abdominal aortic aneurysm repair T.A. Bley, P. Chase, K. Shinki, S. Reeder, C. Francois, G. Teferra, T. Grist, M. Pozniak; Madison, WI/US ([email protected]) Purpose: To evaluate the clinical utility of volumetric analysis of non-contrast CT as the sole method to follow-up endovascular abdominal aortic repair and to identify presence of clinically significant endoleaks. Methods and Materials: The study had institutional review board approval. Retrospective image review was performed in a HIPPA compliant manner on 230 CT studies from 70 patients (11 female and 59 male, mean age 74 years) who underwent endovascular abdominal aortic aneurysm repair (EVAR). The scan protocol consisted of: 1) contrast enhanced CT angiography (CE-CTA) prior to endostent; 2) CE-CTA at 0-3 months following repair to detect immediate complications; 3) non contrast (NC) CT scans at 3, 6 and 12 months. For each follow-up visit, immediate aortic volume analysis was performed. If the interval volumetric change was b 2%, no further imaging was performed. If the volume increased by 2% on the NCCT scan, a CE-CTA scan was immediately performed to identify suspect endoleak. Results: Mean volume decrease was -3.2% (95% CI -4.7%, -1.9%) in intervals without occurrence of a clinically relevant endoleak (n=183). Type 1 and 3 “high pressure” endoleaks (n=10) showed a 10.0% (95% CI 5.0%, 18.2%) interval volumetric increase. Type 2 “low pressure” endoleaks (n=37) showed a 5.4% (95% CI 4.6%, 6.2%) interval volumetric increase. Endoleaks associated with minimal aortic volume changes 2% were clinically not significant and did not require any intervention in our patient population. Conclusion: NCCT aortic aneurysm volumetric analysis can adequately screen for the presence of clinically significant endoleaks. B-415 14:36 Using engineering mathematical models and CT 4D imaging to understand the hemodynamics after aortic prosthesis insertion L.V. Forzenigo1, M. Domanin1, A. Veneziani2, L. Gabrielli1, C. Vergara1, P. Biondetti1, S. Romagnoli1, A. Molinari1, L. Antiga1; 1Milan/IT, 2Atlanta, GA/US ([email protected]) Purpose: Mathematical models have an important role in industrial engineering and an increasing role also in the biomedical field. A good example is the hemodynamic evaluation of patients after insertion of aortic prosthesis. Our goal was to analyze the virtual haemodynamics of aortic flow after endoprosthesis insertion and to optimize the design of the prosthesis related to: aortic flow pattern, heart function, aneurysmal thrombus, endoleak and endotension. Methods and Materials: Our experience concerns six patients who underwent endoprosthesis insertion because of AAA. Each patient was studied before intervention with Doppler ultrasound and double source ECG-gated 64 rows CT angiography (4D imaging). After aortic endoprosthesis insertion, these patients had Doppler ultrasound and double source ECG-gated 64 rows CT follow-ups at 1, 3, 6, 12 and 24 months. Because of ECG-gated acquisition (4D), images were available for each phase of the R-R interval. CT DICOM data were sent to Politecnico Engineering for 3D reconstruction of the anatomy and simulation of aortic haemodynamics before and after prosthesis insertion; also the interaction with the intra-aneurysmal thrombus was evaluated. Results: Preliminary results show that after endoprosthesis insertion, there is an increase of intra-aortic flow velocity, with a decrease of lateral pressure. The rigid prosthesis interrupts the pressure wave originated with the cardiac pulsation, with retrograde negative effects on the heart function. Conclusion: Computed modelling of aortic flow haemodynamics can help to optimize the prosthesis design, tailoring it to each patient. Scientific Sessions B-416 14:45 Endoleak detection with CT angiography in an aortic aneurysm phantom: Effect of tube energy and physical properties of endoleaks Z. Szucs-Farkas, M. Semadeni, S. Bensler, M.A. Patak, G. von Allmen, P. Vock, T. Schindera; Berne/CH ([email protected]) B-417 14:54 Comparing true and virtual non-contrast phases of dual source computed tomography in the diagnosis of patients with endovascular repair of aortic aneurysms W.H. Sommer, A. Graser, D.-A. Clevert, K. Nikolaou, M.F. Reiser, C.R. Becker, T.R.C. Johnson; Munich/DE ([email protected]) Purpose: For patients with status post endovascular repair of aortic aneurysms, unenhanced CT scans are necessary for differentiation of calcifying thrombus from contrast-agent, i.e., an endoleak. This study determined whether virtual non-contrast (VNC) images derived from dual energy CT (DECT) examinations can replace true non-contrast (TNC) acquisitions. Methods and Materials: 62 patients with aortic stentgrafts underwent dual-sourceCT scan (Siemens SOMATOM-Definition) including single-energy non-contrast and dual energy scan in the venous contrast phase (Ultravist 370, BayerSchering). On a five point scale, two experienced radiologists evaluated image quality (for VNC and TNC), acceptance level and subtraction of calcification (for VNC). Presence of endoleaks was assessed based on contrast enhanced images and either (1) VNC or (2) TNC images. Dose-length products derived from the scan protocol were used to estimate effective doses for both non-contrast and contrastenhanced acquisitions. Percent differences for a single-phase and a dual-phase protocol were calculated. Results: Nineteen endoleaks were detected among the patients. Mean image quality was rated “good” for VNC (1.92p0.96) and "excellent" for TNC (1.17p0.38; p 0.05). In 62 of 65 patients (95.4%), VNC images were diagnostic. Subtraction of calcification in VNC images was classified as none (56.9%), minimal (20.0%), moderate (15.4%) or severe (7.7%). Mean effective dose was 9.37p0.33 and 9.21p0.27 mSv for unenhanced and DECT-scans, respectively. Dose-reduction for a single phase protocol was 50%. Conclusion: DECT allows reliable detection of endoleaks in patients with status post endovascular repair of aortic aneurysms. In comparison to current examination protocols, omission of a non-contrast phase will lead to a 50% dose-reduction. B-418 15:03 Detection of endoleaks after endovascular repair of aortic abdominal aneurysm: A new biphasic single-injection with single-acquisition MDCTangiography protocol B.J. GonГ§alves, A. Gil-Agostinho, M. Seco, A. Canelas, V. Carvalheiro, F. Caseiro-Alves; Coimbra/PT ([email protected]) Purpose: To evaluate the feasibility of a new MDCT protocol using biphasic enhanced single-acquisition for the detection of endoleaks after endovascular repair (EVAR) of aortic aneurisms (AA). To compare the radiation dosages and imaging findings of this new protocol with those from classic protocol using multiphase acquisition. B-419 15:12 Reproducibility of MR arteriography and flow to quantify therapeutic macrovascular response in peripheral arterial disease B. Versluis1, M. Van Eupen1, P.J. Nelemans1, E.V. Rouwet2, J.A.W. Teijink2, J.E. Wildberger1, W.H. Backes1, T. Leiner1; 1Maastricht/NL, 2Heerlen/NL ([email protected]) Purpose: Non-invasive imaging techniques are urgently needed to evaluate therapeutic response in peripheral arterial disease (PAD) and to detect vascular adaptations. The aim was to assess the reproducibility of MR arteriography to quantify the number of arteries and the flow of conduit arteries. Methods and Materials: Ten healthy volunteers and ten patients with proven PAD (Fontaine stadium II) and collateral formation were prospectively imaged twice within 1 week. The subjects underwent 3D contrast-enhanced MR arteriography covering the entire upper leg and subsequent phase-contrast flow waveform measurements in the superficial femoral (SFA) and popliteal artery (PA). Two independent readers determined the number of arteries bypassing on five transverse planes at 5 cm distance. Inter- and intra-observer reproducibility was expressed by intra-class correlation coefficients (ICC) and repeatability coefficient (RC), where RC quantifies the smallest detectable change. Results: The number of arteries per slice was significantly higher in patients (15.7 p 3.5) than in volunteers (12.9 p 2.5, P 0.01). Intra-observer reproducibility (i.e. repeated acquisitions) of artery count showed high ICC (0.98), whereas the inter-observer reproducibility was slightly lower (volunteers: 0.72, patients: 0.85). RC in patients was 1.1. Peak systolic flow was significantly lower in patients (SFA, 7.7 p 3.6; PA, 4.5 p 2.8 mL/s) compared to volunteers (SFA, 15.6 p 2.5; PA, 9.6 p 2.5 mL/s, P 0.01). ICC of flow was 0.90 in patients and 0.93 in volunteers for both the SFA and PA. RC in patients was 1.7 mL/s (SFA) and 1.9 mL/s (PA). Conclusion: MR-derived angiographic artery count and flow quantification provide reproducible measurements to evaluate morphological and functional adaptations of macrovasculature in PAD. B-420 15:21 Evaluation of vessel size imaging to detect antiangiogenic therapy response S. Zwick1, R. Strecker2, V. Kiselev3, P. Gall3, M. Palmowski4, W. Semmler1, F. Kiessling4; 1Heidelberg/DE, 2Erlangen/DE, 3Freiburg/DE, 4Aachen/DE ([email protected]) Purpose: To assess vascular remodelling in tumors during antiangiogenic therapy with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and vessel size imaging and to evaluate the vessel size index (VSI) as a novel biomarker of therapy response. Methods and Materials: In total 12 tumor-bearing nude mice (6 controls, 6 therapies) were investigated with DCE-MRI and vessel size imaging before and after 4 days of multitargeted tyrosine kinase inhibitor treatment (SU11248). MRI measurements were performed on a clinical 1.5 T whole-body MRI system. DCE-MRI data were analysed applying a two-compartment model (Brix), calculating the parameters Amplitude and kep. Afterwards the tumors were investigated by histology. Results: The parameter Amplitude decreased significantly over time in treated tumors (0.20 p 0.09 a.u). compared to untreated ones (0.02 p 0.08 a.u)., whereas kep showed no significant change in treated (0.28 p 0.41 1/min) over untreated (-0.05 p 0.25 1/min) tumors. Also the VSI was capable to mirror antiangiogenic A B C D E F G H S233 Saturday Purpose: To analyze detection of endoleaks with low tube voltage CT angiography (CTA). Methods and Materials: A cylindrical plastic phantom mimicking an aortic aneurysm containing a stent graft and 36 simulated endoleaks of various diameter (2, 4, and 6 mm) and distance from the graft (0, 5 and 10 mm) was placed into a water container corresponding average sized patient weighing ca. 72-85 kg. CT scanning was done at 80, 100 and 120 kVp and volume CT dose indices (CTDIvol) were noted. Three radiologists independently analyzed CT images for endoleak localization with diagnostic confidence and image quality. Analysis of variance was used to compare results and to find parameters with effect on endoleak detection. Results: All 6 mm endoleaks were correctly identified at all tube energies. Observers detected more 4 mm leaks at 100 kVp compared to 80 kVp (p= 0.006). The overall sensitivity was only 2.8% for the 2 mm endoleaks. The diagnostic confidence increased parallel with tube energy (p= 0.004). CTDIvol was by 27% lower at 80 kVp compared to 100 kVp. Diameter and position of endoleaks and tube voltage had all a significant effect on the number of detected leaks (p 0.0001). Conclusion: Reduced radiation exposure is achievable with CTA using 80 kVp in average sized patients with no risk of missing endoleaks measuring 6 mm or larger. 100 kVp protocols are advisable if the threshold for endoleaks demanding therapy is defined at 4 mm. Methods and Materials: A total of 30 patients (25 men, 5 women) with abdominal AA submitted to EVAR were referred to MDCT evaluation. A new MDCT-angiography protocol was set up. First an unenhanced scan was performed. Enhanced scan included an initial injection of 50 mL of iodine contrast (without any delay and at a rate of 4 mL/min). After a delay of 60 sec another injection of more 50 mL using bolus tracking was given and followed by a 30 mL saline flush (3 mL/sec). Imaging findings were compared with the former MDCT evaluation (6 to 12 months of interval between the two exams) that used the classic protocol with 2 enhancement phases (arterial and venous). Dose reports were also compared. Results: Within the classic protocol evaluation, endoleaks were diagnosed with the arterial phase in 20 (66%) and with the venous phase in 30 (100%) patients, respectively. Within this new protocol all the previously detected endoleaks were diagnosed in all patients (n = 30). This protocol also contributed to a mean of 34.3% reduction of the effective dose delivered. Conclusion: A biphasic single-injection with single acquisition protocol works as a mixed venous-delayed arterial phase enabling detection of early or delayed endoleaks. Scan time and radiation exposure can also be decreased by eliminating a second enhanced acquisition. Scientific Sessions therapy response showing significant higher changes in treated (7.6 p 7.7 Вµm) than in untreated tumors (-3.9 p 5.4 Вµm) over time. Histological analysis proved the success of the antiangiogenic therapy and showed lower mean vessel area fractions in treated tumors, and an increase of the mean vessel size in treated compared to untreated tumors. Conclusion: Results of both methods are in excellent agreement with histology. DCE-MRI and vessel size imaging provide reliable and supplementing biomarkers of antiangiogenic therapy response. 14:00 - 15:30 Room N/O Neuro SS 711 Stroke Moderators: F. Pizzini; Verona/IT J. Walecki; Warsaw/PL B-421 14:00 Combined use of arterial spin labelling and susceptibility-weighted imaging in acute stroke helps predict hemorrhagic transformation S. Altrichter1, R. Sztajzel1, L. Sekoranja1, M. Viallon1, F. Lazeyras1, M. Vargas1, J. Delavelle1, A. Federspiel2, K.-O. LГёvblad1; 1Geneva/CH, 2Berne/CH ([email protected]) Purpose: We wanted to determine if the combined use of arterial spin labelling (ASL) and susceptibility-weighted imaging (SWI) could improve the detection of hemorrhage in acute stroke. Methods and Materials: We prospectively examined 31 patients (aged 50-89 years) with acute stroke. Imaging was performed between 1 day and 2 weeks on a 3.0 T Magnetom Trio (Siemens; Erlangen, Germany). ASL was performed with a PASL sequence, using a QUIPSII perfusion mode, RelCBF maps for ASL were calculated in-line by the MRI scanner, and off-line for CEPWI using the Syngo Perfusion (MR) software (Siemens Medical Solutions). SWI was performed using a 3D acquisition. CEPWI was also acquired as well as DTI with a 30-direction scan. Results: Acute ischemic lesions were seen on DWI in all cases, whereas hypoperfusion was observed in 29. There was a perfect match between ASL and CEPWI in 21 cases. Hypoperfusion was observed on ASL in ten cases and hyperperfusion in nine cases. Hemorrhage or BBB breakdown were visible on SWI in seven cases. Early SWI changes together with hypoperfusion were associated with the occurrence of hemorrhage. Hyperperfusion on ASL was not associated with hemorrhage in the absence and presence of changes on SWI. Conclusion: The presence of hyperperfusion on ASL perfusion seems indicative of reperfusion/collateral flow that is protective of hemorrhagic transformation. The combination of hypoperfusion and changes on SWI seems on the other hand to predict hemorrhage. Thus, combining these techniques in addition to standard schemes, increases the power of MRI to predict tissular outcome in acute stroke B-422 14:09 Detection of intracerebral hemorrhage with flat-detector CT compared to multislice CT: Preliminary results in 44 cases T. Struffert, T. Engelhorn, M. Doelken, P. GГ¶litz, W. Kalender, O. Ganslandt, A. Doerfler; Erlangen/DE ([email protected]) Purpose: The aim of the study was to test the reliability of intracerebral hemorrhage (ICH) detection with flat-detector computed tomography (FD-CT) as compared to multislice CT (MSCT). Methods and Materials: In this study, 44 patients with 45 ICH were included. All patients were investigated with FD-CT and MSCT. As a control group, we included 16 patients without ICH. In each haematoma, we assessed volumetric data of the ICH and counted the numbers of ICH positive slices. Using interobserver rating, we additionally investigated the potential of FD-CT to serve as a diagnostic tool to detect ICH. Results: In FD-CT, three haematomas were not detected because of motion and beam hardening artifacts in the region close to the skull base. The r value for the degree of interobserver agreement for the number of slices was 0.95 for MSCT and 0.94 for FD-CT. Measurements of the area and the calculated volume of the ICH showed high inter- and intraobserver agreement. Conclusion: Our results indicate that FD-CT is a helpful tool in the daily emergency management of ICH patients as detection of ICH was found to be nearly as reliable as in MSCT. Limitations of this technology are motion and beam hardening artifacts that may mask small haematomas located in the posterior fossa or the skull base. S234 A B C D E F G F H B-423 14:18 The role of 3D susceptibility-weighted imaging in the detection of cerebral microbleeds in lacunar infarction patients X. Hong, D. Wang; Nanjing/CN ([email protected]) Purpose: Lacunar infarcts are small strokes that lie in the deep noncortical parts of the cerebral hemispheres and brain stem. Our purpose was to evaluate the role of susceptibility-weighted imaging (SWI) in the detection of microbleeds in lacunar infarction patients. Methods and Materials: Using a Siemens 3.0 T MR unit, 254 cases showing abnormal signal on T2 and FLAIR, consistent with lacunar infarct, were included in this study. The MRI examination consisted of axial T1-weighted fl2d imaging, axial T2-weighted fast-spin echo imaging, axial FLAIR fast-spin echo imaging and 3D susceptibility-weighted imaging. Results: Of the 254 cases (male144, female 110, average age 65.5 years), SWI showed evidence of microbleeds in 62 cases (male 51 and female 11), compared to 15 (male 11 and female 4) with T1, T2 and FLAIR. Cerebral microbleeds were detected in significantly more persons (P 0.01) with SWI (24.4%), compared with conventional T2 and FLAIR imaging (5.9%). There were no cerebral hemorrhages visualized on the conventional MRI sequence that were not detected on the SWI sequence. Microbleeds were found in 35.4% of male patients and only in 10% of female patients. Microbleeds were almost four times more frequent in elderly (= 60) than in younger patients ( 60; 31.3 versus 8%, P 0.05). Conclusion: The 3D SWI is more sensitive than the conventional MRI sequences for the detection of cerebral microbleeds that may prove useful in the treatment of lacunar infarction. Microbleeds are not rare in old patients. It is recommended as part of MR study in the elderly or prior to anticoagulation treatment. B-424 14:27 High-risk carotid artery plaques increase the risk of ischemic stroke in asymptomatic individuals: A study from the Cardiovascular Health Study J.F. Polak1, J.C. Nelson2, T.A. Manolio3, D. Lefkowitz4, D.H. O’Leary5; 1 Boston, MA/US, 2Seattle, WA/US, 3Bethesda, MD/US, 4Winston-Salem, NC/US, 5 Dorchester, MA/US ([email protected]) Purpose: It is believed that certain ultrasound characteristics of carotid artery plaque are associated with an increased risk of stroke. We investigated this in a longitudinal follow-up of asymptomatic members of the Cardiovascular Health Study aged 65 years. Methods and Materials: Clinical characteristics and cardiovascular risk factors were acquired during a baseline clinic visit. Plaques were categorized as high risk (HR) with a degree of stenosis 50% or heterogeneous-echolucent according to the European consensus meeting or markedly irregular plaque surface, low risk for absent plaques (LR) and moderate risk (MR) for all other plaques. Ultrasound findings were blindly interpreted from videotape without access to clinical information. Stroke was ascertained in 12 years of follow-up by panel review of clinical records. Cox proportional hazards models were use to evaluate the association between plaque characteristics and the risk of ipsilateral ischemic stroke as determined by blinded panel review. Results: HR plaques were seen in 465 of 5425 individuals. The stroke rate was significantly higher for HR 9.2% (43/465) and MR (6.1% 225/3704) compared to LR (4.1% 51/1256) plaques. The risk of stroke remained higher for HR (154, 57, 312%) and MR (56, 17, 108%) compared to LR plaques after adjustment for age, race, sex and major CHD risk factors. Conclusion: Ultrasound appearance of carotid plaque can identify a subset of asymptomatic older individuals with increased risk of stroke. B-425 14:36 Assessment of the patency of the major dural venous sinuses with standard CT angiography in the setting of intraparenchymal cerebral hemorrhage J.E. Delgado Almandoz, H.S. Su, P.W. Schaefer, S.R. Pomerantz, M.H. Lev, J.M. Romero; Boston, MA/US ([email protected]) Purpose: To determine the frequency of adequate contrast opacification of the dural venous sinuses during the initial CT angiogram (CTA) in patients presenting with intraparenchymal hemorrhage (IPH), an essential factor in the exclusion of dural sinus thrombosis (DST) as the IPH etiology. Methods and Materials: We conducted a retrospective review of the initial CTAs performed in 75 consecutive patients presenting to our Emergency Department with IPH. Two neuroradiologists determined whether contrast opacification in each of the major dural venous sinuses was adequate to exclude DST. Delayed scans, if obtained, were also reviewed. CTAs were performed in a 64-slice CT scanner with Scientific Sessions Smart-Prep technique by scanning from C1 to the vertex following administration of 65-80 mL of contrast material. Results: In the first-pass CTA, adequate contrast opacification was achieved in 77% of the superior sagittal, 68% of the right transverse, 61% of the left transverse, 40% of the right sigmoid and 33% of the left sigmoid sinuses. Delayed scans were obtained in 23 cases (31%, range 5-310 seconds after first-pass scan), 21 of which demonstrated adequate contrast opacification in all the major dural sinuses (91%). A diagnosis of DST was subsequently made in 4 patients (5%), none of which demonstrated adequate contrast opacification in the affected dural venous sinus during the first-pass or delayed scan (if obtained). Conclusion: In the setting of an IPH, inadequate contrast opacification of a major dural venous sinus during the first-pass CTA should prompt acquisition of a delayed scan to exclude DST as the IPH etiology. B-426 14:45 Stroke-CT: Initial experiences with whole brain perfusion-CT D.F.B. Morhard, C. Wirth, M.F. Reiser, C.R. Becker; Munich/DE B-427 14:54 Whole-brain 4D-CT in stroke patients: Our initial experience J. Ferda1, H. MГrka1, T. Flohr2, B. Schmidt2, J. Baxa1, B. Kreuzberg1; 1Plzen/CZ, 2 Forchheim/DE ([email protected]) Purpose: To assess the clinical value of dynamic whole-brain CT (4D-CT) in patients with suspected stroke. Methods and Materials: The prospectively collected data were evaluated in 25 patients (mean age 55.1 years; 14 males, 11 females) with suspected hemispheric stroke. The adaptive multiphase spiral data acquisition covering the entire brain volume, i.e. time-resolved scanning of a region larger than the detector width by continuous periodic table movement, was performed in 25 cycles every 1.5 s performed after application of 30 ml of iodinated contrast material. The collimation of 20 x 1.2 mm was used. The 5 mm images were reconstructed to analyze whole-brain perfusion and 1.5 mm images (0.7 mm increment) to create dynamic angiograms (4D-CTA). The perfusion maps of the entire brain were calculated. Results: No perfusion or circulation disorder was found in 12 patients, some perfusion deficit in 9 patients, circulation disorder without perfusion deficit in 3 patients and brain tumor in 2 patients, respectively. The localization of the perfusion deficit extended the conventional area of perfusion CT in six patients, including five in whom additional information was obtained from whole-brain perfusion. Compared to the static CTA, 4D-CTA enabled additional description of collateral circulation or the cause of the perfusion deficit in four cases, three cases of pure circulation disorders and in tumors. 4D-CTA combined with whole-brain perfusion offered additional information in 48% of the patients Conclusion: 4D-CT covering the entire brain improves the assessments of ischemia including its extent, perfusion deficits and collateral circulation. 15:03 Quantitative imaging of spontaneous neuromagnetic activity for assessing cerebral ischemia using sLORETA-qm S. Sakamoto1, N. Tsuyuguchi1, Y. Terakawa1, H. Tanaka2, W. Ide3, I. Hashimoto3, H. Kamada3, Y. Inoue1; 1Osaka/JP, 2Kanazawa/JP, 3Obihiro/JP ([email protected]) Purpose: To image cerebral neural activity in the ischemic area, we proposed a novel technique to analyze spontaneous neuromagnetic fields based on standardized low-resolution brain electromagnetic tomography modified for a quantifiable method (sLORETA-qm). Methods and Materials: Using a 160-channel whole-head-type magnetoencephalographic (MEG) system, cerebral magnetic fields were obtained from pre- and postoperative conditions of 5 patients with unilateral internal carotid artery occlusive disease and 16 age-matched healthy volunteers. For quantitative imaging, voxelbased time-averaged intensity of slow waves in 4 frequency bands (0.3-2, 2-4, 4-6 and 6-8 Hz) were obtained by the proposed technique based on sLORETA-qm. Positron emission tomography with 15O gas inhalation (15O-PET) was also performed in these patients to evaluate cerebral blood flow and metabolism. Results: In all 5 patients, slow waves of every frequency band were distributed in the area of cerebrovascular insufficiency confirmed by 15O-PET preoperatively. In 4 patients, slow-wave intensities in theta bands (4-6 and 6-8 Hz) decreased postoperatively along with improvements in cerebral blood flow and metabolism, whereas delta bands (0.3-2 and 2-4 Hz) showed no significant differences between pre- and postoperatively. One patient with deterioration of cerebral infarction after surgery showed marked increases in slow-wave intensities in delta bands (0.3-2 and 2-4 Hz) postoperatively, with distribution close to the infarct region. Conclusion: The proposed quantitative imaging of spontaneous neuromagnetic fields enabled clear visualization of cerebral neural conditions in the ischemic area. This technique may offer a novel, non-invasive method for identifying cerebral ischemia. B-429 15:12 Low-dose neurovascular HYPR-CT methods H. Rowley, M. Supanich, K. Pulfer, G.-H. Chen; Madison, WI/US Purpose: Radiation dose reduction and noise reduction for the same dose are demonstrated for dynamic, contrast-enhanced neuro CT protocols using highly constrained back projection (HYPR)-CT methods. Methods and Materials: Raw CT projection data from 12 patients and 26 canine scans, all with neurovascular defects, using a standard CT perfusion protocol were saved and processed for retrospective reconstruction. Radiation dose reduction was simulated via view-angle undersampling. Dose reduction factors of 10 were simulated using one-tenth the acquired projection data along with the HYPR-CT method to maintain waveform fidelity and noise characteristics of a fully sampled series. The HYPR-CT method was implemented to produce standard 5 mm slicethickness perfusion maps and 64-slice dynamic CTAs at simulated dose reduction factors up to 10. HYPR-CT methods were also used to improve image quality for 0.625 mm slice-thickness perfusion analysis at full dose. Results: Correlation between ROIs from standard and HYPR-CT reconstructed perfusion maps greater than 0.9 have been demonstrated for up to a sixfold simulated dose reduction with coefficients of variation consistent with scan-to-scan variations. HYPR-CT dynamic CTAs show a squared difference of less than 0.05 from standard reconstructions at a simulated dose reduction of 10 during contrast uptake for vascular ROIs. Noise is reduced by a factor of 2.5 over standard reconstruction at the same dose using HYPR CT methods for 64-slice perfusion analysis. Conclusion: HYPR CT methods produce an immediate decrease in image noise on existing platforms and offer a potential sixfold reduction in radiation dose for contrast-enhanced acquisitions while maintaining image quality and physiological information. B-430 15:21 CT perfusion in predicting delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage N. Khandelwal, P. Singh, S.H. Tirumani, A. Pathak, V. Gupta; Candigarh/IN ([email protected]) Purpose: Evaluation of role of CT Perfusion (CTP) in predicting delayed cerebral ischaemia (DCI) after subarachnoid hemorrhage (SAH). Methods and Materials: We prospectively studied the CTP parameters, noncontrast head CT (NCCT) and CT angiography (CTA) at admission in 30 patients with aneurysmal SAH. All were followed for 1 week postoperatively by neurologic assessment and serial NCCT for DCI. We analysed clinical and semiquantitative A B C D E F G H S235 Saturday Purpose: In standard stroke CT protocols, perfusion-CT (PCT) has a detector width-dependent scan range of 1-4 cm. Recently introduced toggling table technique PCT offers the opportunity to cover ranges of the entire brain volume (VPCT), and additional reconstructions provide time-resolved CTA (4D-CTA). The purpose of our study was to evaluate the benefit of VPCT and 4D-CTA compared to standard PCT and CTA. Methods and Materials: A total of 25 patients were scanned with a 128-slice CT scanner. Standard perfusion parameter maps were reconstructed for all data sets, as well as 4D-CTA (64 slices Г 1.5 mm, time resolution of 1.5-3 s) and standard intracranial CTA reconstructions (slice thickness 1.0 mm). For evaluation, two different image samples were created: VPCT-group: perfusion parameter maps of the whole scan range and 4D-CTA; standard group: 2 x 10 mm parameter maps at the basal ganglia, similar to standard PCT and standard CTA. A consensus reading was performed by two radiologists to evaluate the impact of VPCT and 4D-CTA compared to the simulated standard group. Results: In eight (32%) of these data sets, pathological brain perfusion was detected with VPCT. In four (50%), subsegmental infarctions superior to the basal ganglia were not covered in the standard PCT group. In all patients with restricted brain perfusion, pathological changes were found in 4D-CTA, while one vascular pathology (13%) was not detected with standard CTA alone. Conclusion: VPCT helps to detect infarctions in the more superior levels of the brain compared to standard PCT. The 4D-CTA can provide additional information about hemodynamics and relevant information in a small group of patients. B-428 Scientific Sessions CTP parameters between patients with and without DCI. Statistical analysis was done using nonparametric tests (p-value 0.05). Results: DCI was more common in females and in patients with low GCS at presentation. Fisher Grading for SAH showed no significant association with DCI. In 19 patients with DCI, average lowest rCBF and rCBV were 0.77 and 0.85. Average highest dTTP and dMTT were 1.20 and 1.35. The corresponding values in 11 patients without DCI were 0.90, 0.91, 1.07 and 1.14 respectively. With threshold values of 0.75, 0.80, 1.0 and 1.1 for CBF, CBF, MTT and TTP, the sensitivities of dTTP and dMTT were 95% and 70%, and specificities were 30% and 43% respectively for predicting DCI. rCBF and rCBV had sensitivity of 43% and 40%, and specificity of 85% and 71% respectively. The relative risk was 1.875 for elevated dMTT ( 1.15). Conclusion: CTP is easily available and can be combined with NCCT and CTA for predicting DCI after SAH. TTP is a sensitive predictor of vasospasm and combination of TTP and CBF has a better sensitivity/specificity than individual parameters. 14:00 - 15:30 Room P Chest SS 704 Airway imaging and functional data Moderators: N. Howarth; ChГЄne-Bougeries/CH S. Ley; Heidelberg/DE B-431 14:00 Radiologic-pathologic correlation: Accuracy of automatically assessed bronchial wall-thickness T. Achenbach1, O. Weinheimer1, C. Brochhausen1, D. Hollemann1, C. Stanger1, C.P. Heussel2, C. Dueber1; 1Mainz/DE, 2Heidelberg/DE ([email protected]) Purpose: Increase of airway-wall-thickness in MDCT is an important marker for inflammatory bronchial changes e.g. in COPD patients. Automated measurements have shown high accuracy in phantom studies if dedicated algorithms as the integralbased-method (IBM) are applied. Up to now, no exact radiologic-pathologic correlation of the same localization of an organic bronchus was published as morphology preserving preparation techniques are crucial but difficult. The aim of this study was to test the accuracy of our automated measurement method. Methods and Materials: Immediately after euthanization, two porcine lungs were excised by thoracotomy, intubated and submerged into a bath of liquid nitrogen while inflated by a lung ventilator. The frozen and ventilated lungs were scanned and appropriate levels were ink-marked by MDCT and its gantry-laser. Frozen sections from bronchi of these levels were cut and stained by hematoxylin and eosin. Medians of microscopically (CellB, Sof Imaging System GmbH) and MDCTassessed wall-thicknesses were compared. Results: Airway morphology was well preserved after microtome cutting allowing comparison of CT- and microscopic images. By the time of submission, the first slice was correlated. Airway wall thickness was 0.62 mm assessed with MDCT and the IBM (1.06 mm by standard full-width-at-half-maximum-technique) and 0.58 mm with digital microscopic measurement. Conclusion: Quick-freezing of inflated porcine lungs preserved bronchial morphology enabling direct comparison of CT-images and microscopic images of the same localization. Hence, for the first time in a non-phantom setting, automated wall-thickness assessment of a bronchus demonstrated high accuracy with a tendency towards overestimation. B-432 14:09 Assessment of lobar pulmonary perfusion in COPD patients: Preliminary experience with dual energy CT angiography V. Pansini, M. RГ©my-Jardin, J.-B. Faivre, T. Perez, A. Duhamel, J. RГ©my; Lille/FR ([email protected]) Purpose: To assess pulmonary perfusion on a lobar level in COPD patients using dual energy CT. Methods and Materials: Thirty-eight smokers with a mean cigarette consumption of 30 pack-years underwent a dual energy MDCT angiogram of the chest (Definition, Siemens) with a standard injection protocol. 3D-HRCT data (i.e., contiguous 1-mm thick averaged images from both tubes) were analyzed for detection and quantification of emphysema using a commercially-available software (Pulmo 3D, Siemens). Lung perfusion was analyzed at a lobar level on perfusion scans with automatic quantification of the iodine content at the level of the microcirculation. S236 A B C D E F G F H Eleven nonsmokers scanned in similar conditions served as a control group. Results: Nonsmokers had no alterations in lung structure and a uniform distribution of the iodine content within upper and lower lobes and between right and left lungs (p 0.05). Emphysematous changes were depicted in 26 smokers (68%) including 6 patients with an upper lung zone predominance of emphysema (Group 1) and 20 patients with disseminated areas of hypoattenuation throughout both lungs (Group 2). Perfusion scans of Group 1 patients showed: (a) a significantly lower iodine content within lung microcirculation of the upper lobes compared to smokers without emphysema; and (b) a significantly lower perfusion in the upper lung zones compared to the lower lung zones, matching parenchymal destruction. In Group 2, no significant difference in the iodine content of lung microcirculation could be identified in comparison to non-smokers. Conclusion: Lobar alterations of lung perfusion can be depicted by dual energy CT in COPD patients with heterogeneous emphysema. B-433 14:18 Functional high-resolution digital radiography in diagnosis of chronic obstructive pulmonary disease N. Gorbunov, V. Laptev, S. Pushkarev; Novosibirsk/RU ([email protected]) Purpose: To determine pulmonary optical density and to evaluate respiratory function in patients with chronic obstructive pulmonary disease (COPD). Methods and Materials: The study group comprised 690 patients (283 females, 407 males; mean age 47p 1.2 years, range 16-78 years). There were 419 patients with COPD; the control group included 271 people without pulmonary complaints. We used high-resolution digital radiographic device with a line X-ray sensitive silicate receiver. Lowdose high-resolution digital X-ray examination of the chest was performed both in inspiration and expiration phases. Regional and common pulmonary optical densities were evaluated with further quantitative analysis of respiratory function. Results: It was determined that normal lung density is 660-770 optical density units (odu) for young people till 45 years old, 715-790 odu for moderate age patients (4560 years old) and 790-860 odu for people of 60 and more years old. The respiratory function of pulmonary tissue is normal in case when it is no less than 5.9 for young people, 5.6 and more for people of 45-60 years old and no less than 4.95 for senior people. When pulmonary optical density is lower than normal value, then patient has pulmonary emphysema. On the opposite side, if pulmonary optical density is higher than normal value we suppose pulmonary fibrosis. In all patients with COPD, we observed the decrease of respiratory function. There was significant correlation between pulmonary optical density and respiratory function (p 0.01). Conclusion: Functional high-resolution digital radiography may be useful for prognosis in patients with COPD and for treatment selection. B-434 14:27 Global and regional airway obstruction in patients with severe homogeneous emphysema: Quantitative analysis of volumetric paired thin section multi detector computed tomography scans and pulmonary function tests A. Grgic1, H. Wilkens1, J.-M. Kuhnigk2, E.-M. Jung3, G. Sybrecht1, R. Kubale4, A. Buecker1; 1Homburg a.d. Saar/DE, 2Bremen/DE, 3Regensburg/DE, 4 Pirmasens/DE ([email protected]) Purpose: To investigate the correlation of pulmonary function tests - (PFT) and CT scans obtained in - and expiration and to assess the lobar gas trapping in homogeneous emphysema. Methods and Materials: 48-patients (mean age-60p9 years) with severe emphysema due to COPD-GOLD IV were included in this retrospective study. All scans were performed during inspiration and expiration using a 16-channel MDCT. MDCTdata were analyzed with MeVisPULMO3D-software to give following parameters: lung volume-LV, emphysema index-EI, emphysema volume-EV, core-CV to peel-PV volume and four clusters (2, 8, 65, 120 mmВі) for whole lung and each lung lobe separately. These results were correlated with PFT-data: forced expiratory volume in 1 second-(FEV1), inspiratory vital capacity-(VCin), residual volume-(RV), total lung capacity-(TLC), RV/TLC and 6-minute walking distance. Results: Inspiratory-LV correlated well with TLC (p 0.001), expiratory-LV with RV (p 0.001). The mean inspiratory-EI of 37p9% decreased by 25p9% (p 0.001) during expiration resulting in a change of EV by 930 p 370 ml (p 0.001). Change of LV from inspiration to expiration correlated with RV/TLC (p 0.001), FEV1 (p 0.001) and VCin (p 0.001). Change of EV, CV, PV correlated with RV/TLC, FEV1 and VCin (all p 0.05), but change of large emphysema clusters showed better correlation with RV/TLC, FEV1 and VCin (p 0.001). The comparison of lobar RV/TLC CT indexes (192 lobes) correlated well with change of lobar volume, EV, CV, PV and large clusters (all p 0.001). Scientific Sessions Conclusion: While morphological changes are better reflected in the static lung volumes obtained from MDCT, dynamic changes in PFT-data correlate better with dynamic changes in MDCT. Lobar analysis provides better insights into the regional hyperinflation areas. B-435 14:36 Short-term reproducibility of navigator-triggered oxygen-enhanced MRI of the lung F. Molinari1, M.U. Puderbach2, M. Eichinger2, S. Ley2, L. Bonomo1, H.-U. Kauczor2; 1Rome/IT, 2Heidelberg/DE ([email protected]) B-436 14:45 Simulated smooth kernel images obtained by post-reconstruction filtering of sharper kernel reconstructions in chest CT S. Akers, H. Litt; Philadelphia, PA/US ([email protected]) Purpose: Clinical review of chest CT requires reconstruction, evaluation, and storage of several image sets, including reconstructions obtained using sharper lung and smoother mediastinal kernels. We investigated the possibility of creating simulated mediastinal kernel images using post-reconstruction filtering of lung kernel images. Methods and Materials: Simulated mediastinal kernel images were created by applying post-reconstruction filtration to lung kernel (B50f) images from 20 contrast enhanced chest CT examinations using experimental software, allowing the user to simulate any kernel smoother than the original. Images were compared to actual mediastinal reconstructions (B31f). Mean attenuation was measured in 5 ROIs (liver, spleen, lung, pulmonary artery, and outside the patient) in both sets. Differences in average mean attenuation and were evaluated with subjective perception of mediastinal image suitability. Results: Images could be filtered from lung to mediastinal settings instantaneously and viewed using clinical software. There were no significant differences in mean attenuation between the true and simulated mediastinal images in any ROI, with average difference in mean attenuation of 1% for each. Subjectively, simulated mediastinal images appeared somewhat sharper than actual mediastinal images, without limiting diagnostic utility. Conclusion: Post-reconstruction filtering of lung kernel reconstructions can reproduce mean attenuation values of a smoother mediastinal kernel. If clinical equivalence of simulated reconstructions can be demonstrated in studies encompassing a range of pathology, this may result in savings in scanner and radiologist time and image storage. Additionally, radiologists would not be limited to pre-specified reconstructions, but could choose the kernel most suitable for each image, diagnosis, or patient. 14:54 Phenotyping of COPD: Comparison of an anatomical and a non-anatomical approach in studying the distribution of emphysema between the upper and lower lung M. Owsijewitsch1, J. Ley-Zaporozhan1, J.-M. Kuhnigk2, C.P. Heussel1, H.-U. Kauczor1, S. Ley1; 1Heidelberg/DE, 2Bremen/DE ([email protected]) Purpose: Studying the distribution of the emphysematous regions is one step towards phenotyping COPD. We compared two currently applicable approaches for studying the distribution of emphysema in the upper and the lower lung with 3D-HRCT, the comparison of lung lobes (anatomical) and the comparison of not anatomically defined halves of the lung divided by a transverse plane. Methods and Materials: We investigated 100 patients with GOLD stages 0 (at risk)-4. A dedicated tool (MeVisPULMO3D) was used. After the automatic lung and lung lobe segmentation, the emphysema indices (EI, 950 HU) for lobes and halves (divided by a transverse plane at the level of carina) of each lung were calculated. The EI of the upper lobes was compared with the EI of the upper halves and accordingly the EI of the lower lobes with the EI of the lower halves. In the right lung, the volume weighted means of the EIs of the upper and middle lobes were compared with the EIs of the upper halves. Results: In patients with GOLD stages 0, 1 and 2 (average EI 10%), differences between the EIs of the lobes and halves for both the upper and lower lung were in the range of 25% of the global EI and were highly significant (P 0.001), but not significant in patients with stages 3 and 4. Conclusion: For less severe disease groups, it is essential to perform the lobebased analysis for correctly phenotyping the disease. In GOLD classes 3 and 4 with a homogenous distribution of emphysema, there is no difference between both approaches. B-438 15:03 Comparison of dynamic MRI, CT and nuclear medicine for prediction of postoperative lung function in lung cancer Y. Ohno, H. Koyama, M. Nogami, D. Takenaka, Y. Onishi, K. Matsumoto, K. Sugimura; Kobe/JP ([email protected]) Purpose: To compare the predictive capabilities for postoperative lung function in non-small cell lung cancer (NSCLC) patients of the state-of-the-art radiological methods, including dynamic perfusion MRI, quantitative CT and co-registered SPECT/CT, with that of anatomical method (i.e. qualitative CT) and traditional nuclear medicine methods such as planar imaging and SPECT. Methods and Materials: Dynamic perfusion MRI, CT, perfusion scan including SPECT and measurements of %FEV1 before and after lung resection were performed for 229 NSCLC patients (125 men and 104 women). For perfusion MRI, postoperative %FEV1 (po%FEV1) was predicted from semi-quantitatively assessed blood volumes within the total and resected lungs; for quantitative CT, it was predicted from the functional lung volumes within the total and resected lungs; for qualitative CT, from the number of segments of total and resected lungs; for nuclear medicine studies, from uptakes within the total and resected lungs. Predicted po%FEV1s were then correlated with the actual po%FEV1s, and the limits of agreement between the actual and predicted po%FEV1 were evaluated. Results: All po%FEV 1s showed good correlation with actual po%FEV 1s (0.83brb0.88, P 0.0001). The limits of agreement of dynamic perfusion MRI (4.4 p 14.2 %), quantitative CT (4.7 p 14.2 %) and co-registered SPECT/CT (5.1 p 14.7 %) were less than those of qualitative CT (6.0 p 17.4 %), planar imaging (5.8 p 18.2 %) and SPECT (5.5 p 16.8 %). Conclusion: State-of-the-art radiological methods can predict postoperative lung function in NSCLC patients more accurately than traditional methods. B-439 15:12 Quantitative assessment of airway remodelling in difficult asthma S. Gupta, R. Clark, S. Siddiqui, P. Haldar, J. Entwisle, R. Green, I. Pavord, A. Wardlaw, C. Brightling; Leicester/UK ([email protected]) Purpose: Our aim was to measure airway dimensions in two different airways on high resolution computed tomography (HRCT) in patients with difficult asthma and compare it with healthy individuals. We also explored the correlation between dimensions of two different airways and their association with clinical characteristics. Methods and Materials: All difficult asthma clinic (DAC) patients were extensively characterised in terms of history, lung function, health status and airway inflammation. HRCT was performed using 16 detector multislice scanner and images reconstructed using a bone algorithm. The geometry of right B1 (RB1) and right B10 (RB10) airways were measured by full-width at half-maximum (FWHM) principle using EmphylxJВ© software in 106 DAC patients and 10 healthy control A B C D E F G H S237 Saturday Purpose: To investigate the repeatability of diagnostic quality, signal and ventilation defects of the oxygen-enhanced (OE) maps in healthy subjects and lung cancer patients. Methods and Materials: OE-MRI was performed twice in 36 subjects within 24 h (16 patients, 20 healthy volunteers; t0-24 h-t2). In the volunteers, OE-MRI was also rapidly repeated within the first day (t0-t1). Four coronal OE-maps were obtained per examination (dorsal to ventral; 1.5 T MR-system; navigator-triggered IR-HASTE). Diagnostic quality (Q) and signal (S) of the maps were evaluated by 3 radiologists. 4 lung regions per map (right-upper; right-lower; left-upper; left-lower) were assessed for ventilation defects (VD). Volunteers and patients were considered separately (Qv; Sv; VDv; Qp; Sp; VDp). Results: Qv/Qp was diagnostic=94.4/78.1% (sufficient=46.7/58.3%, optimal=47.8/19.8%) and not diagnostic=5.6/21.9% of times (K-inter-p=0.49-0.88; K-intra-p=0.29-0.82). Comparing t2 and t1 vs. t0 in volunteers and t2 vs. t0 in patients, Sv/Sp was better=27.5/31.3%, equal=51.7/37.5%, worse=20.8/31.3% of times (K-inter-v=0.56-0.60; K-intra-v=0.15-0.44; K-inter-p=0.44). 13 VDv over 2880 regions were observed by only one reader, 2 matched among t0 and t1, none were reproduced at t2. 44 VDp over 1536 regions were found at t0 (15 by 1, 8 by 2, 21 by 3 readers), 77 at t2 (27 by 1, 8 by 2, 42 by 3 readers), 40 matched t0 and t2 (13 by 1, 6 by 2 and 21 by 3 readers). Conclusion: The diagnostic quality and signal of the oxygen-enhanced maps show lower inter- and intra-observer variability in volunteers than in patients. Ventilation defects in lung cancer patients may be reproduced after 24 hours. B-437 Scientific Sessions subjects. Corrections were made for the oblique orientation of the airways and body surface area (BSA). Results: DAC cohort and control subjects were matched for age [Mean (SEM)]: 50.6 (1.3), 49.2 (4.7), respectively. The lung functions were significantly impaired in DAC cohort; FEV1% predicted: 74.3 (2.7), 101.2 (4.8) [p=0.005]; FEV1/FVC: 69.6 (1.4), 80.6 (2.1) [p=0.0271]. There was good correlation between corrected RB1 and RB10 dimensions. Corrected mean (RB1 and RB10) %WA was significantly greater in DAC: mean (sem) %WA, DAC [68.4 (0.7)] and controls [63 (1.0)]; p=0.0053. Corrected RB1 %WA revealed similar results. The correlation between corrected RB1 and clinical parameters was statistically significant for: (1) LA/BSA and disease duration (R2=0.12); (2) %WA and FEV1% (R2=0.16), JACS (R2=0.10), disease duration (R2=0.08), sputum neutrophils (R2=0.06). Multiple regression analysis revealed that FEV1% best predicts RB1 %WA (R2=0.23, p=0.003). Conclusion: The DAC group had evidence of airflow limitation and airway wall thickening. These findings were correlated suggesting that the airflow obstruction is in part due to airway remodelling. B-440 B-442 15:21 In-vivo respiratory-gated micro-computed tomography can demonstrate airway remodeling in a mouse asthma model M. Lederlin1, M. Montaudon1, P. Berger2, A. Ozier2, F. Laurent1; 1Pessac/FR, 2 Bordeaux/FR ([email protected]) Purpose: An imaging method for in vivo assessment of bronchial remodeling in animal asthma models would be highly useful for preclinical studies. The aim of our study is to evaluate the feasibility of noninvasive respiratory-gated micro-CT for the assessment of airway remodeling in a mouse asthma model. Methods and Materials: The study was approved by the local animal care committee. Twelve female BALB/c mice were challenged intranasally with ovalbumin. All mice underwent plethysmographic study on day 0 and after the last intranasal instillation. The mice were then scanned using micro-CT. On the resulting images, peribronchial densities of 12 bronchi were measured for each mouse. The mice were then killed and lungs examined histologically. Results: Final analysis involved 10 out of 12 mice. A significant difference in peribronchial densities between asthmatic mice and control mice was found (p 0.05). A strong correlation was observed between peribronchial density values and histological parameters like peribronchovascular space (p = 0.025) and bronchial muscle area (p = 0.018). Repeatability of measurements over observers and over time was very good (intraclass correlation coefficients ranging from 0.94 to 0.98). Conclusion: By measuring density of the peribronchial atmosphere, in vivo respiratory-gated micro-CT enables to determine if a mouse is normal or asthmatic. Noninvasive respiratory-gated micro-CT appears therefore to be a reliable methodology for monitoring bronchial remodeling in the lung and, potentially, for evaluating the effects of new treatments. 14:00 - 15:30 Room Q Interventional Radiology Liver: TACE Moderators: L. Hechelhammer; Zurich/CH J. Tacke; Passau/DE 14:00 Precision V: A randomized phase II trial of a drug-eluting bead in the treatment of hepatocellular carcinoma by transcatheter arterial chemoembolization T.J. Vogl1, K. Eichler1, K. Malagari2, F. Pilleul3, A. Denys4, A. Watkinson5, R. Lencioni6, M. Funovics7, J. Lammer7; 1Frankfurt a. Main/DE, 2Athens/GR, 3 Lyon/FR, 4Lausanne/CH, 5Exeter/UK, 6Pisa/IT, 7Vienna/AT ([email protected]) Purpose: To compare DEB-TACE with conventional TACE for the treatment of intermediate-stage HCC in patients with cirrhosis. Methods and Materials: A total of 212 patients (185 males and 27 females; mean age, 67 years) with Child-Pugh A or B liver cirrhosis and large and/or multinodular, unresectable HCC were randomized to receive DEB (DC Bead; Biocompatibles, UK) loaded with doxorubicin or conventional TACE with doxorubicin. Randomization was stratified according to Child-Pugh status (A or B), performance status (ECOG 0 or 1), bilobar disease (yes or no) and prior curative treatment (yes or no). Tumor S238 A B C D 14:09 Hepatocellular carcinoma: The post transcatheter arterial chemoembolization scar or tumor tissue, comparison of 3.0 T MR diffusion-weighted imaging and PET-CT L. Yu Bao; Guangzhou/CN ([email protected]) Purpose: To evaluate the post transcatheter arterial chemoembolization (TACE) scar or tumor tissue of hepatocellular carcinoma (HCC) by 3.0 T MR diffusionweighted imaging (DWI) and PET/CT, to analyze whether the value of ADC correlated with the post TACE scar or tumor tissue. Methods and Materials: Twenty-two patients with HCC were enrolled in our study. All the patients underwent TACE. 3.0 T MR diffusion weighted imaging was performed with b value of 600 s/mm2. An Echo-planar sequence was performed. The ADC values of the lesion after TACE were measured in diffusion weighted images. All the patients underwent fluorodeoxyglucose (FDG) positron emission tomography CT (FDG-PET/CT) examinations after the MR examinations. It was analyzed whether the value of ADC correlated with the scar or tumor tissue of HCC after TACE. The scar or tumor tissue of HCC after TACE was confirmed by PET/CT and clinical follow-up. The values of ADC of the scar or tumor tissue and normal liver tissue were compared. The data were analyzed by SPSS13.0 statistical software and p 0.05 was considered to be significant. Results: All patients with post TACE scar or tumor tissue of HCC were confirmed by PET/CT. Compared with the results of PET/CT, the mean ADC of tumor tissue was 1.92Г—10-3 mm2/sec, The mean ADC of scar tissue was 6.59Г—10-3 mm2/sec. The mean ADC between scar and tumor tissue were statistically significant (p=0.021). Conclusion: The ADC value of DWI is a promising functional magnetic resonance imaging tool for prediction of therapeutic response to TACE. Compared with PET/ CT, DWI is useful in the differential diagnosis of scar tissue and tumor tissue in patients with HCC after TACE. B-443 14:18 Transarterial chemoembolization and radiofrequency ablation in the treatment of hepatocellular carcinoma: Differentiation of viable residual tumor with CT-perfusion technique D. Ippolito1, F. Invernizzi2, M. Scorza1, M. Pozzi1, L. Antolini1, S. Sironi1; 1 Monza/IT, 2Lecco/IT ([email protected]) SS 709b B-441 response at 6 months was the primary study endpoint. An independent, blinded review of MRI studies was conducted to assess tumor response according to amended RECIST criteria. Results: DEB-TACE with doxorubicin showed a higher rate of complete response, objective response and disease control compared with conventional TACE (27 vs 22%; 52 vs 44%; and 63 vs 52%, respectively; P 0.05). Patients with Child-Pugh B cirrhosis, ECOG 1 performance status, bilobar disease and recurrence following curative treatment showed a significant increase in objective response (P = 0.038) compared to the control. There was a marked reduction in serious liver toxicity in patients treated with DEB-TACE. The rate of doxorubicin-related side effects were significantly lower (P = 0.0001) in the DEB-TACE group compared with the conventional TACE group. Conclusion: DEB-TACE with doxorubicin is safe and effective in the treatment of intermediate-stage HCC and may offer a significant benefit to patients with more advanced disease. E F G F H Purpose: To assess the value of CT-perfusion technique (CT-p) in quantifying the residual vascularity in hepatocellular carcinoma (HCC) treated with TACE and RFA. Methods and Materials: CT-perfusion study was performed in 72 patients with liver cirrhosis and known diagnosis of hepatocellular carcinoma. Out of 72 patients, 53 were treated with TACE, while the remaining 19 patients were treated with RFA. Dynamic CT study was performed with a 16-slice multi-detector-computed tomography (Philips Brilliance,16 P, NL) with the following protocol: acquisition of 8 dynamic slice/scan for a total of 40 scans after i.v. injection of 50 ml of iodinated contrast (350 mgI/ml) with a flow rate of 6 ml/sec.The data were analyzed using a dedicated software (CT perfusion 2.0 workspace), which calculated the following parameters: hepatic perfusion (HP), blood volume (BV), arterial perfusion (AP), hepatic perfusion index (HPI), time to peak (TTP). All the obtained data were expressed by mean o standard deviation and were statistically analyzed using univariate Wilcoxon test. Results: A complete treatment of neoplastic lesion was not obtained in 41 out of 72 patients in whom the following quantitative perfusion parameters were found: HP 32.7 p 15 ml/100 gr/sec; BV 17.6 p 9.5 ml/100 gr; AP 38.4 p 8.8 ml/min; TTP 19 p 5.7 sec; HPI 61.3 p 32.7%.The corresponding values obtained in the remaining 31 cases in whom a complete necrosis was achieved were: HP 13.6 p 5.7 ml/100 gr/sec; BV 6.8 p 4.8 ml/100 gr; AP 13.1 p 7 ml/min; HPI 13.6 p 9.2 % and TTP 29 p 16.1 sec. Our data showed that HP, AP, BV and HPI values were higher (P 0.001), whereas Scientific Sessions TTP was lower in HCC lesions unsuccessfully treated.These findings were related to the presence of residual viable vascular structures. Conclusion: CT-p technique may have a complementary role in diagnosing residual HCC blood perfusion, thus helping in the assessment of tumor response to treatment. B-444 14:27 Transarterial chemoembolization in down-staging program for hepatocellular carcinoma prior to liver transplantation: The Bologna workin-progress experience A. Cappelli, E. Giampalma, M. Renzulli, C. Mosconi, R. Golfieri; Bologna/IT ([email protected]) B-445 14:36 Comparison of bland embolization versus drug eluting bead embolization for the treatment of BCLC stage B hepatocellular carcinoma K. Malagari, M. Pomoni, M. Angelopoulos, H. Moschouris, E. Emmanouil, A. Pomoni, A.D. Kelekis, P. Vasiliou, D. Kelekis; Athens/GR ([email protected]) Purpose: To evaluate the added role of the chemotherapeutic in transarterial embolization (TACE) of intermediate stage hepatocellular carcinoma (HCC). The issue is of major importance since hypoxia is a potent stimulator of angiogenesis. This is suggested by recent evidence that shows that bland embolization increases the serum levels of angiogenic factors such as VEGF and insulin growth factor. Several studies up to now have shown that chemoembolization performs better than bland embolization but the variability of the parameters of TACE compromise the strength of these results. The hypothesis was that since DEB-TACE allows a standardized and reproducible TACE the comparison with bland TACE can readily reveal the potential added value of the chemotherapeutic. Methods and Materials: Two groups of patients were enrolled in this prospective study: group A- treated with doxorubicin DEB-TACE (n = 20) and group B (n = 22) treated with bland embolization. Patients included were BCLC stage B, with measurable lesions randomized for tumor size. Results: Tumor response was evaluated with the RECIST criteria using the EASL amendment. In group A complete response on an intention to treat basis was seen in 6 patients (30%). Objective response ranged from 65% to 80% across treatments. In group B complete response was achieved in 18.18% while objective response ranged from 50% to 68.18% across treatments. There were no significant differences in the levels of AFP between the two groups. Conclusion: DEB-TACE with DC bead presents better tumor response than bland embolization; however, survival benefit has to be shown in future studies. 14:45 First evaluation of a phase III study comparing TACE-DC beads IRI loaded (DEBIRI) with FOLFIRI (CT) for patients with nonresectable colorectal cancer (CRC) and liver metastases (LM) C. Aliberti1, G. Benea1, M. Tilli1, I. Marri1, G. Fiorentini2; 1Ferrara/IT, 2Empoli/IT ([email protected]) Purpose: Patients with LM from CRC have a poor prognosis with a 5-year survival of 25% after radical resection, and for not resectable metastases the survival is less than 5%. DC beads are new embolic microspheres capable of loading IRI. DEBIRI (D) is a combination of drug infusion with embolization of the LM feeding arteries. It is a safe and feasible procedure (ASCO GI abs 356, Jan 2007; IN VIVO 21, 6, 2007; ASCO GI abs 480, Jan 2008). CT containing IRI is active for the treatment of LM from CRC. We planned this phase III study to assess survival as primary endpoint with the goal to increase median survival (MS) by 40% at 2 y (HR = 0.72). Methods and Materials: Between December 2006 and August 2008, 56 patients were randomized, 28 to D (DC Beads loaded with IRI 200 mgr total dose) and 28 to CT. A total of 52 cycles of D were administered, with a relative dose intensity of 99%, and 224 CT cycles were delivered with a relative dose intensity of 85-95%. Results: D increased the 1y MS difference of 20% compared to CT. It improved responses and performance status and reduced costs. D reported higher immediate toxicity, mainly fever, abdominal pain and vomiting, than CT. Intravenously, hydration, morphine and antibiotics were necessary to control these symptoms. Late toxicity, mainly leukopenia, anemia, diarrhoea, asthenia and alopecia, was more common in CT. Conclusion: We conclude that D could reach the goal to increase MS by 40% at 2 y compared to CT. B-447 14:54 Repeated chemoembolisation treatment of liver metastases from neuroendocrine tumors: Survival rates and local tumor control T.J. Vogl, S. Zangos, K. Eichler, M. Nabil, T. Gruber; Frankfurt a. Main/DE ([email protected]) Purpose: To assess, using a combined protocol of Mitomycin C and Gemcitabine, the morphological response and survival rates of patients with hepatic metastases of the neuroendocrine tumor. Methods and Materials: A total of 44 patients (range, 37-77 years) with liver metastases from neuroendorine tumors underwent repeated selective chemoembolization using Mitomycin C and Gemcitabine between 1999 and 2007. Monthly follow-up was performed by CT and MRI for local tumor control. Results: A total of 244 chemoembolizations were performed with a mean of 5.5 sessions per patient at 4-week intervals. Of all the patients, 25 had multiple metastases, 13 had one metastasis, 1 had two metastases, and 5 had three to four metastases. The local chemotherapy protocol consisted of Mitomycin C only (n = 17) and Mitomycin C with Gemcitabine (n = 27). Local tumor control according to the RECIST criteria showed partial response in 13.64% of patients, stable disease in 63.64% and progressive disease in 22.72%. The 1-year survival rate was 88% and the 2-year survival rate was 74. The median survival time from the date of diagnosis was 88 months (according to Kaplan-Meier) and after the first chemoembolization, 40.7 months. For the palliative group, it was 36.9 months, for the symptomatic group 16 months and for the neoadjuvant group 46.6 months. Conclusion: Repeated TACE using Mitomycin C and Gemcitabine allows effective local tumor control and improved survival rates in patients with liver metastases of neuroendocrine tumors. B-448 15:03 Transarterial chemoembolization (TACE) of liver tumors or metastases using drug-eluting beads (DEB): Complications observed I. Kralj1, E.-P. Strecker1, I. Boos2; 1Karlsruhe/DE, 2Woerth/DE ([email protected]) Purpose: TACE using DEB is a relatively new kind of therapy having been proposed as a safe and effective method for highly selective and precise embolization of hepatocellular carcinoma and liver metastases. We will report on a few interesting cases of insufficient results and complications. Methods and Materials: 17 patients underwent 29 TACE embolizations using DC Beads loaded with epirubicin or doxorubicin. When the right and left sides were involved, TACE was performed in two sessions, one side per session. CHILD-C cirrhosis was regarded as contraindication. During the patient’s in-hospital stay after TACE, clinical and laboratory data were assessed. Morphologic response was evaluated with computed tomography (CT) shortly after TACE and repeatedly at follow-up examinations, the longest being 18 months. A B C D E F G H S239 Saturday Purpose: To assess the efficacy and the safety of Trans-arterial Chemoembolization (TACE) in inducing complete tumor necrosis in HCC-patients, confirmed by the histology after liver transplantation (LT). To analyze the overall survival and the tumor recurrence rate of patients both within and exceeding the Milan criteria (MC). Methods and Materials: During 2003-2007 we prospectively analyzed the outcome of 173 patients listed for LT divided in 3 groups: single nodule 3 cm (T1, 37 pts); single nodule b5 cm or multiple nodules b3 with a diameter b3 cm (T2, 93 pts) meeting the MC and the down-stage group (T3, 43 pts): single HCC b6 cm or multiple nodules b6 with a total diameter b12 cm. Eighty-two patients (68.3%) underwent TACE: 7 in T1 (18.9%), 46 in T2 (49.5%), 29 in T3 (67.4%). Results: Histology after LT demonstrated a complete tumor necrosis in 61 patients (74.4%) and partial necrosis in 21 patients (25.6%). The degree of necrosis directly correlated with the selectivity of TACE: 80.6% of cases were treated with superselective TACE versus 46.7% with a lobar TACE. After a median follow-up of 28.3 months, the overall tumor recurrence rate was 14.6% and the overall survival was 82%. The recurrence rate was comparable among the groups and it did not affect significantly the patients survival. Conclusion: TACE is safe and effective in obtaining a complete tumor necrosis when performed in a superselective way compared to lobar procedures. The preoperative tumor stage does not affect patient survival and the down-stage group had comparable outcome than the others. B-446 Scientific Sessions Results: Pain was observed in all patients, 1 patient had high-grade pain requiring peridural analgesia. Severe procedure-related complications: necrotizing cholecystitis (2), one of them necessitating cholecystectomy; necrotizing pancreatitis (1); partial liver necrosis and abcess (1); gastric ulceration (1); pleural effusion (1). Further observations: small splenic infarction (1); gas within embolized area (2); and incomplete embolization (2). Conclusion: DEB is highly effective in embolization of liver tumors. As according to a rapid and complete occlusion of arteries, the risk of adverse side effects may be high also. From our experience, we recommend embolization of the cystic artery in case of tumor localization near the gallbladder. 14:00 - 15:30 B-449 B-451 15:12 Palliative and symptomatic treatment of primary hepatic cholangiocarcinoma with repeated transarterial chemoperfusion and embolization: Local tumor control and survival rate T.J. Vogl, S. Zangos, K. Eichler, T. Gruber; Frankfurt a. Main/DE ([email protected]) Purpose: To evaluate the local tumor control and survival data in the palliative and symptomatic treatment of hepatic cholangiocarcinoma (CCC) using repeated transarterial chemoperfusion and embolization (TACE) with two different chemotherapy protocols. Methods and Materials: A total of 41 patients with primary cholangiocarcinoma (CCC) were repeatedly treated with transarterial chemoembolization (TACE) at 4-week intervals. In total, 291 TACE sessions were performed with a mean of 7.1 sessions per patient (mean age: 57.1 years; range, 37-80 years). Of all the patients, 22 had multiple tumors, 6 showed one lesion, 5 had two lesions and 8 presented with three to four lesions. The local chemotherapy protocol consisted of Mitomycin C alone (n = 20) or in combination with gemcitabine (n = 18). Embolization was performed with lipiodol and starch microspheres for vessel occlusion. Tumor response was evaluated by magnetic resonance imaging (MRI) at 3-month intervals. Results: The evaluation of local tumor control according to RECIST criteria was as follows: partial response 9.8%, stable disease 43.6% and progressive disease 46.6%. The 1-year survival rate after TACE was 58% and the 2-year survival rate was 21%. The mean survival time from the date of diagnosis of liver involvement was 34.1 months (according to Kaplan-Meier) and after the first TACE treatment, 16.7 months. The median survival time of the palliative group was 14.5 months and of the symptomatic group 6 months. Conclusion: Our data indicated that repeated TACE using the protocols is well tolerated and yields respectable results in patients with unresectable liver lesions from CCC. B-450 15:21 Angiographic cone beam C-arm volume CT with a flat panel detector prior to TACE: Does it add useful information on the arterial tumor supply and portal veins? B.C. Meyer, B.B. Frericks, M. Witschel, K.J. Wolf, F.K. Wacker; Berlin/DE ([email protected]) Purpose: To assess the arterial tumor supply and portal vein with C-arm CT (CACT) in comparison to DSA in patients undergoing TACE of the liver. Methods and Materials: A total of 30 patients (hepatocellular carcinoma, n = 10, malignant ocular melanoma, n = 12, hypervascular liver metastases, n = 8) underwent arterial and portal venous CACT (breath-hold technique, resolution 0.4 mmВі) of the liver using intraarterial contrast media administration as well as DSA immediately prior to TACE. After assessing the DSA images, CACT images were reviewed on a 3D workstation. Number and origin of the tumor feeding arteries, ideal position of the catheter for TACE, presence of segmental portal vein thrombosis and of breathing artifacts in both, DSA or on CACT, were assessed and correlated. Results: The number of vessels identified as tumor feeders was significantly higher in CACT than in DSA (CACT: 1.4 p 0.6 and DSA:1.0 p 0.3, P = 0.003, t-test). After consideration of the CACT images, the position of the catheter for TACE was changed in 15 cases to a less selective position (n = 9) or to a more selective position to presevere healthy liver tissue (n = 3) or the gall bladder (n = 3). Breathing artifacts were observed in both, CACT (n = 3) and DSA (n = 2), but did not interfere with image interpretation. A segmental portal vein thrombosis was seen in three patients in CACT, but only in one in DSA. Conclusion: As CACT depicts soft tissue as well as small vessels in high-spatial resolution, tumor vessel allocation is facilitated and the ideal catheter position for TACE can be chosen more precisely. Due to the higher contrast resolution of CACT in comparison to DSA, portal vein pathologies are better visualized. S240 A B C D E F G F H Room R Cardiac SS 703 Imaging viability and valve disease Moderators: J. Barkhausen; LГјbeck/DE S. Potthast; Basle/CH 14:00 Impact of radiation dose and contrast material volume in the assessment of acute reperfused myocardial infarction with 64-slice delayed enhancement CT: A porcine model C. Martini1, E. Maffei1, A.A. Palumbo1, C. SaccГІ1, M.L. Dijkshoorn2, A.C. Weustink2, N.L. Mollet2, F. Cademartiri1; 1Parma/IT, 2Rotterdam/NL ([email protected]) Purpose: To compare the impact of dose and contrast material volume in DelayedEnhancement CT imaging for the assessment of acute reperfused myocardial infarction. Methods and Materials: In ten 2-month-old domestic pigs (mean weight: 24 kg), circumflex coronary artery was balloon-occluded for 2 h followed by reperfusion. After 5 days, DE-CT imaging was performed 15 min after administration of iodinated contrast. The scan protocol was performed in spiral cardiac mode: fixed pitch (0.2), HR (51 p 9 bpm; pharmacologically induced), at two tube current values (350/900 mAs) with two iodinated contrast material volume (30/100 ml). The scans performed were: ART (CTA first-pass), DE1 (15 mAs/kg-1.25 gI/kg), DE2 (37.5 mAs/ kg-1.25 gI/kg), DE3 (15 mAs/kg-3.75 gI/kg), DE4 (37.5 mAs/kg-3.75 gI/kg). Infarct and no-reflow size were defined as the hyperenhanced and dark area, respectively, and expressed as percentage of total remote myocardial area. CT attenuation values were measured using five regions of interest: DE, no-reflow, remote myocardium, left ventricular cavity, air, respectively. Differences, correlations, S/N and C/N were calculated. Results: Infarct area showed a significant increase with higher dose and contrast material volume with best visualization in DE4. S/N and C/N were the highest for DE 2.4 (6.0 and 3.6, respectively) as compared to DE 1.3 (4.0 and 2.2, respectively). Significant differences were found between the Hounsfield-Unit of DE 2.3 versus DE 3.4, however the correlation was very high including the S/N and C/N (R2 0.90). Conclusion: The amount of contrast material is far more important than radiation dose for the assessment of DE-CT. The best DE-CT can be obtained with a volume of contrast material which is 2-3 times the amount usually employed for standard Cardiac-CT in humans. B-452 14:09 Influence of time-to-reperfusion on the extent of the area at risk (RA), infarct size (IS) and microvascular obstruction (MVO) in patients with STelevated acute myocardial infarction (STEMI): A cardiovascular magnetic resonance (CMR) study M. Francone, L. Agati, F. Vasselli, I. Iacucci, J. Carbone, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: Salvage of viable myocardium within the RA and limitation of infarct expansion are the mechanisms by which patients with STEMI benefit from reperfusion. CMR with late enhancement (LE) and T2 weighted short tau inversion recovery (T2w-STIR) imaging may represent an ideal tool for the assessment of effects of time-to-treatment on IS, MVO and myocardium potentially salvaged. Methods and Materials: 70 patients with first STEMI treated with PCI within 12 hours from symptoms onset underwent CMR in the first week after admission. For the purpose of the study, patients were divided into 4 groups according to different time-to-reperfusion intervals: Group-A ( 1.5 hrs; n=19); Group-B ( 1.5-3 hrs; n=17); Group-C ( 3-6 hrs; n=17); Group-D ( 6-12 hrs; n=17). CMR protocol included T2w-STIR, 1st-pass and LE sequences after Gd-BOPTA administration (Multihance, Bracco). IS, MVO and RA were quantified from DE and T2w MRI; peri-infarction zone was determined as the ratio between RA and IS. Results: Median time-to-reperfusion was 4.4p4.7 hrs. Shorter time-to-reperfusion was associated with smaller IS (Group-A: 9%; Group-B: 15%; Group-C: 14%; Group-D: 18%; Group A vs B, C, D; p =.044). Conclusion: Larger RA (Group-A: 25%, Group-B: 15%; Group-C: 16%, Group-D: 9%) and peri-infarction zones were also observed in patients treated earlier (Groups AB vs CD p 0.01). Lately reperfused STEMI (Group D) had significantly larger MVO areas (Group D vs A, B, C; p=.041) with higher prevalence of intramyocardial Scientific Sessions hemorrhage. This study further support the importance to shorten treatment delay of STEMI patients and emphasizes diagnostic role of CMR protocol with LE and T2w techniques providing in vivo characterization of tissue damage at different temporal stages of reperfusion. B-453 14:18 Ageing of the human heart: Can physical exercise attenuate the morphological, functional and metabolic alterations of the left ventricle? A magnetic resonance imaging and magnetic resonance spectroscopy study E. Belloni, F. De Cobelli, G. Perseghin, A. Esposito, T. Canu, G. Alberti, L. Luzi, A. Del Maschio; Milan/IT ([email protected]) B-454 14:27 Contrast-enhanced MRI is superior to PET in myocardial viability assessment of patients with impaired left ventricular function P. Hunold1, A. Marcin2, T. Schlosser2, K. Brandt-Mainz2, R. Pink2, L. Freudenberg2, H. Eggebrecht2, P. Massoudy2, J. Barkhausen1; 1LГјbeck/DE, 2Essen/DE ([email protected]) Purpose: To evaluate MRI and PET for myocardial viability assessment in CAD patients with different LV functional states. Methods and Materials: 105 CAD patients were examined by MRI and PET. MRI (1.5 T) contained a TrueFISP study to assess LV function. 8-15 min after 0.2 mmol/ kg Gd-DTPA, a segmented inversion-recovery TurboFLASH study (TR, 8 ms; TE, 4 ms; TI, 200-240 ms) was performed to quantify Late Gd enhancement (LGE) extent based on a 6-segment model in short axes. In [18F]-FDG-PET, corresponding short axis slices were acquired and assessed using an analogous scale. Detection of scar and prediction of functional recovery were compared in patients with ejection fractions (EF) of 30, 30-50, and 50%. Results: 5508 myocardial segments were analysed. 2474 of 5508 (45%) segments provided LE in MRI vs. PET uptake deficits in 2220 (40%) segments. Scar detection in patients with EF 30%: MRI, 1341 (55%), PET, 1116 (46%) of 2453 segments. In this group, functional recovery was predicted in 1456 (66%) segments by MRI vs. 1834 (75%) by PET. In patients with EF 30-50%: scar was detected in 1022 (44%) vs. 927 (40%) of 2301 segments. Functional recovery was predicted in 1674 (72%) vs. 1852 (80%). EF 50%: scar detected in 111 (15%) vs. 177 (23%) of 754 segments. Functional recovery was predicted in 687 (91%) and 710 (94%) of 754 segments by MRI and PET. Conclusion: Contrast-enhanced MRI detects more scars in patients with severely and moderately impaired LV function than PET. In MRI, fewer segments are predicted to recover function after revascularization. 14:36 Microvascular obstruction after acute myocardial infarction: When is the optimal time point for detection with contrast-enhanced magnetic resonance imaging? K.-F. Kreitner, N. Abegunewardene, K. Oberholzer, T. MГјnzel, C. DГјber, G. Horstick; Mainz/DE ([email protected]) Purpose: To determine the optimal time point for detection of microvascular obstruction (MO) in patients with acute myocardial infarction (AMI). Methods and Materials: 41 patients with AMI and successful recanalization underwent two CMR examinations at 1.5 T within 10 days, the first within 48 hours after AMI. For assessment of late enhancement (LE) and MO, we used an inversion prepared 2D and 3D-segmented TurboFlash sequence in short-axis orientation of the heart. LE and MO were measured 2 (early enhancement) and 10 minutes (late enhancement) after application of 0.2 mmol Gd-DTPA /kg bw. The left ventricle was further assessed planimetrically. Results: Areas of MO were detected in 32/41 early and in 31/41 patients late after contrast application at exam 1. The number decreased at exam 2 to 23/41 and 15/41 patients, respectively. MO areas decreased from 5.5 to 3.0% between early and late enhancement (p 0.001) at exam 1, and from 5.5 to 2.6 at early enhancement (p 0.001), and from 3.0 to 1.2 at late enhancement (p 0.001) between exam 1 and 2. Areas of LE decreased between exam 1 and 2 from 19.5 p 12.1 % to 14.1 p 9.1% (p 0.001). Conclusion: The real extent of MO is best assessed on images obtained 2 minutes after contrast application and within 24-48 after acute MI. The areas of LE decreased from the acute to the subacute phase after AMI. For assessment of prognostic parameters, CMR imaging should be done within 48 hours after AMI. B-456 14:45 Potential of Gd-BOPTA for assessment of myocardial viability on MRI: Delayed enhancement imaging and measurement of T1-values G.A. Krombach1, M. Neizel1, J. Boehringer1, H. KГјhl1, C. Hahnen1, K.-P. Lodemann2, N. KrГ¤mer1, F. Schoth1, R.W. GГјnther1; 1Aachen/DE, 2 Konstanz/DE ([email protected]) Purpose: To compare gadobenate (Gd-BOPTA) injected at a dose of 0.1 mmol/kg bodyweight with a dose of 0.2 mmol/kg bodyweight of gadopentetate (Gd-DTPA) for delineation of myocardial infarction. Methods and Materials: In 52 patients with myocardial infarction, we obtained delayed enhancement images after injection of either gadobenate (n=26) or gadopentetate (n=26) at a 1.5 T MR scanner and measured regional T1 values prior, 3 and 25 min after injection of contrast medium using a Look Locker sequence. On delayed enhancement images, we obtained contrast between infarcted and remote myocardium and assessed image quality subjectively applying a 4-point scale. Results: In the group, that received Gd-BOPTA T1 values of remote myocardium were 1070p125 ms, 358p78 ms and 562p108 ms prior and 3 and 25 min after injection, and of infarcted myocardium 1097p148 ms, 246p68 ms and 373p84 ms prior and 3 and 25 min after injection. In patients, which received Gd-DTPA T1 values were: 1087p96 ms, 325p60 ms and 555p108 ms for remote myocardium and 1134p109, 210p43 ms and 304p83 ms for infarcted myocardium prior, 3 and 25 min after injection. Image quality of delayed enhancement images showing myocardial infarction was rated as good (44) and excellent (28) after Gd-BOPTA and good (51) and excellent (37) after Gd-DTPA with no significant differences between the groups. Conclusion: Gd-BOPTA at low dose compared to a double dose of Gd-DTPA provides a similar contrast between infarcted and remote myocardium (0.64p14 versus 0.71p11) and slightly higher contrast between left ventricular blood and infracted myocardium (0.22p17 versus 0.14p6). After administration of 0.1 mmol/ kg bodyweight Gd-BOPTA late enhancement images with similar image quality compared to the standard dose of 0.2 mmol/kg of Gd-DTPA can be obtained. B-457 14:54 Molecular multidetector computed tomography (MDCT) imaging for visualization of deposited myocardial calcium in reperfused infarction M. Carlsson, M. Saeed; San Francisco, CA/US ([email protected]) Purpose: Calcium overload during reperfusion is a major contributor of myocardial necrosis. This study aimed to assess the ability of 64-slice MDCT in quantifying deposited calcium in reperfused infarction. Methods and Materials: Reperfused infarction was produced in 7 pigs by percutaneous coronary catheterization. Animals were imaged at 2-4 hrs, 1 week and 8 weeks after reperfusion using a 64-slice GE MDCT. Baseline non-contrast imaging A B C D E F G H S241 Saturday Purpose: Assess whether the ageing-related morpho-functional and metabolic changes of the left ventricle (LV) are attenuated in middle-aged men involved in long-lasting physical activity. Methods and Materials: Magnetic resonance imaging (MRI) and 31Phosporousmagnetic resonance spectroscopy (31P-MRS) were performed on 20 healthy young and 25 healthy middle-aged men with a sedentary lifestyle (11 young and 14 middle-aged) or undergoing regular aerobic training (9 young and 11 middle-aged). Short-axis cine SSFP images, encompassing both ventricles from base to apex, were obtained to perform LV morpho-volumetric and systolic function analysis. Phase contrast images were obtained to perform LV diastolic function evaluation. 31P spectra were obtained with a dedicated surface chest coil for transmission detection of radiofrequency signals at the resonance frequency of 31P. The volume of interest was positioned avoiding inclusion of chest wall and diaphragm muscles. Results: The physically active individuals were characterized by higher LV mass and volumes. Sedentary young and middle-aged men were not different in LV morphological parameters and systolic function. The PCr/ATP ratio (marker of phosphates metabolism) and the LV E/A peak flow ratio were lower in the middleaged sedentary than in the middle-aged physically active subjects. Parameters of LV systolic function and the PCr/ATP ratio were not different in the middle-aged and in the young trained men. Conclusion: Trained middle-aged subjects showed a better pattern of LV energy metabolism and of diastolic function than the sedentary counterparts; this could be a preliminary evidence that in long-lasting physical activity the ageing process of the heart is attenuated. B-455 Scientific Sessions (120 kV/200 mAs, 2.5 mm slice thickness covering the heart, in plane spatial resolution 0.625 mm) for calcium quantification and delayed contrast enhanced (DE) imaging (120 kV/600 mAs, 0.625 mm isotropic voxels) after 2 ml/kg Omnipaque 300 mg/ml, for infarct quantification, were obtained. Postmortem studies were used to confirm and measure extents of deposited calcium and infarction. Results: Deposited calcium was evident on non-contrast enhanced MDCT in the core of the infarction at 1week (13.6p2.7% of infarcted myocardium), but not at 2-4 hrs (0.8p0.4%). At 8 weeks small remnants of deposited calcium was found (2.7p0.7%), suggesting calcium resorption. At 1 week, there was a correlation between the extent of deposited calcium and infarction size (r=0.70). Attenuation of deposited calcium was greater (89p6 HU) than remote myocardium (36p3, P 0.05). Contrast media administration obscured the visualization of deposited calcium, because the differential contrast with surrounding infarcted tissue diminished on DE-MDCT. Hematoxylin eosin and calcium-specific staining (von Kossa) confirmed the extent of deposited calcium. Conclusion: MDCT characterized the spatial distribution of deposited calcium in infarcted myocardium and has the unique ability to monitor progression and regression of deposited calcium in reperfused infarction. B-458 15:03 Evaluation of valve dynamics as a new MRI parameter in the assessment of valvular aortic stenosis M. Weininger, F. Sagmeister, C. Ritter, F. Weidemann, M. Beissert, D. Hahn, H. KГ¶stler, M. Beer; WГјrzburg/DE ([email protected]) Purpose: To investigate a non-invasive assessment of the valvular response to the variation of flow during systole in severe valvular aortic stenosis using velocityencoded phase-contrast MRI (VEC-MRI) compared to invasive measurements and transthoracic echocardiography (TTE). Methods and Materials: 16 patients (8 male, 8 female; mean age 70p8) with severe aortic stenosis (echocardiographic orifice area 1.0 cmВІ) were examined using a 1.5 T MRI scanner and a standardized scanning protocol consisting of SSFP phase-contrast velocity imaging (VEC-MRI). Temporal changes of the aortic valve area (AVA), determined by manual planimetry of VEC-MRI images, were used to assess valvular dynamics by calculating the time-frame of the ejection period, which AVAs spent over 85% of the maximal AVA. Calculations were done by dividing the number of frames with AVA over 85% by all frames of the ejection period. MRI results were compared to invasive measurements according to the Gorlin formula (AVAGorlin) and the effective orifice area using TTE. Results: Values for time spent over 85% determined by VEC-MRI were 34p14%. Mean values of the effective orifice area (TTE) were 0.78p0.14 cmВІ and for the invasively calculated AVAGorlin 0.79p0.19 cmВІ. Comparing VEC-MRI to TTE and to AVAGorlin a significant correlation was found for both: r=0.61/p 0.05; r=0.70/p 0.01. Conclusion: In severe aortic stenosis, a high correlation was found between MRI measurements and clinical gold standards (TTE and invasive measurements). VEC-MRI seems to provide a new parameter to quantify aortic valve dynamics (opening and closing characteristics). It might help to evaluate the hemodynamic and physiologic severity of the stenosis. B-459 15:12 Initial experience with a low-dose protocol for prosthetic heart valve evaluation using a 256 detector-row CT P. Symersky1, R.P.J. Budde2, B.A.J.M. de Mol1, M. Prokop2; 1Amsterdam/NL, 2 Utrecht/NL ([email protected]) Purpose: CT is under investigation as a means for prosthetic heart valve (PHV) assessment. We report our initial experience with a 256-detector row CT (MDCT) for low-dose PHV imaging Methods and Materials: Eight patients with one or more PHV (7 mechanical and 2 biological prostheses; 7 aortic and 2 mitral) underwent cardiac ECG-gated 256-detector row CT (Philips iCT), using either (1) a novel low dose scan protocol with a low-dose (120 kV, 50-80 mAs) unenhanced retrospective scan followed by prospective gated CTA (120 kV, 200-250 mAs) at maximum valve opening and closure or (2) a standard retrospectively gated CTA (120 KV 600-700 mAs). Systematic PHV analysis using both static and dynamic images included the prosthesis (leaflet motion, thrombus), annulus (periprosthetic leak, pannus) and supra- and subvalvular anatomy (septal hypertrophy, false aneurysms). Results: Five patients were scanned using the novel scan protocol. The standard protocol was used in 3 because of arrhythmia, a relatively radiolucent biological valve or additional aortic imaging. Resultant mean dose was 3.55 and 8.25 mSv, respectively. Scan indications included elevated pressure gradient on echocardiography (n=5), suspected thrombus formation (n=2) or follow-up evaluation (n=1). All 9 valve prostheses were successfully visualized with limited artefacts. Prospective gating S242 A B C D E F G F H missed full opening in one biological valve. MDCT findings included: normal valve functioning (n=2), subvalvular calcification (n=3), narrowed left ventricular outflow tract (n=1), leaflet restriction (n=1) and subvalvular pannus tissue (n=2). Conclusion: 256-detector row CT using a low-dose protocol is a promising technique for prosthetic heart valve assessment that provides detailed anatomical information. B-460 15:21 MRI assessment of valve dynamics as a new predictor of left ventricular mass regression in patients with severe aortic stenosis before and after valve replacement therapy M. Weininger, F. Sagmeister, C.O. Ritter, F. Weidemann, M. Beissert, D. Hahn, H. KГ¶stler, M. Beer; WГјrzburg/DE ([email protected]) Purpose: To validate the hemodynamic and clinical relevance of a non-invasive MRI assessment of valvular dynamics in severe aortic stenosis by determining the leftventricular hypertrophy and regression of hypertrophy after valve replacement. Methods and Materials: 22 patients (13 male, 9 female, mean age 68p10) with severe aortic stenosis (echocardiographic effective orifice area, EOA, 1.0 cmВІ) were examined using 1.5 T MRI (SSFP phase-contrast velocity imaging, VECMRI; SSFP-cine-MRI) before and after valve replacement. Temporal changes of the aortic valve area (AVA), determined by planimetry of VEC-MRI images, were used to assess valvular dynamics by calculating the time-frame of the ejection period, which AVAs spent over 85% of the maximal AVA. MRI also determined left-ventricular hypertrophy (LVMI) before/after therapy, and left-ventricular mass regression (LVMR). MRI was compared to EOA and mean transvalvular pressure gradients (PG), determined by transthoracic echocardiography (TTE). Results: Values for time spent over 85% were 33p16%. Mean MRI values of LVMI before valve replacement were 94p22 g/mВІ, after valve replacement 72p17 g/mВІ. Extent of LVMR was -23p18 g/mВІ (-24%). Comparing VEC-MRI to left-ventricular hypertrophy significant correlations were found to LVMI before therapy (r=-0.622/ p=0.002) and LVMR (r=0.624/p=0.002). TTE mean values before/after therapy were: EOA 0.78p0.15 cmВІ/1.91p0.45 cmВІ; PG 52p18 mmHg/14p5 mmHg. Compared to TTE, MRI significantly correlated to EOA (r=0.482, p=0.023) and PG (r=-0.535, p=0.01) before therapy and to the extent of change of PG before/after therapy (r=0.49, p=0.022). Conclusion: MRI parameters of aortic valve dynamics are associated with LVMI and LVMR after valve replacement. MRI correlates with TTE parameters of hemodynamic severity and their postoperative changes. Scientific Sessions A B C D E F G H S243 Sunday Sunday, March 8 Scientific Sessions room A 2nd level room B 2nd level room C 2nd level room E1 entr. level room E2 entr. level room F1 entr. level room F2 entr. level room G/H lower level room I lower level room K lower level 07:00 07:00 07:30 07:30 08:00 08:00 08:30 CC 917 Cardiac Imaging “So you want to perform a cardiac CT H[DPLQDWLRQ"Вґ (p. 58) 09:00 09:30 CC 916 Spinal Imaging and Intervention New WHFKQLTXHV 5HDG\IRUWKH clinical use? (p. 58) NH 9 New Horizons Session 3ODTXH imaging (p. 59) RC 910 Musculoskeletal $UWKULWLV%DFNWR EDVLFV (p. 60) EВі 920a Interactive Teaching Session Colorectal cancer: Diagnosis, staging and follow-up (p. 61) EВі 920b Interactive Teaching Session Imaging in common clinical SUREOHPV Hematuria (p. 61) 08:30 SF 9a Special Focus Session 7KHQHZIDFH of pulmonary infections in Europe (p. 62) SF 9b Special Focus Session Soft tissue vascular malformations (p. 63) RC 913 Physics in Radiology MR-guided cardiovascular interventions (p. 64) SF 9c Special Focus Session Optimising imaging from fetus to adolescent (p. 64) 10:30 EM 3 ESR meets Croatia Breast imaging and interventional radiology in Croatia today (p. 69) 11:00 11:30 SS 1010 Musculoskeletal Knee and cartilage (p. 246) EВі 1020 Interactive Teaching Session Lung cancer: From plain ВїOPWR sectional imaging (p. 70) SS 1001a GI Tract Rectal cancer: MRI (p. 248) 10:30 SS 1007 Genitourinary Imaging of prostate cancer (p. 250) SS 1002 Breast US and follow-up after surgery (p. 252) SS 1001b Abdominal Viscera Liver and ELOLDU\V\VWHP MRI (p. 254) SS 1013 Physics in Radiology New advances in CT (p. 256) SS 1012 Pediatric Fetal and neuro imaging (p. 258) 12:00 Honorary Lecture 2 (p. 70) 13:00 SY 11 GE Healthcare Satellite Symposium (p. 527) SY 12 GE Healthcare Satellite Symposium (p. 527) 13:00 13:30 14:00 14:00 IIQ Image Interpretation Quiz 14:30 15:00 SY 17 Siemens Healthcare and Bayer Schering Pharma Joint Satellite Symposium (p. 528) SY 18 GE Healthcare Satellite Symposium (p. 529) SY 19 Siemens Healthcare Satellite Symposium (p. 529) SY 20 Hologic Satellite Symposium (p. 530) 14:30 15:00 15:30 15:30 16:00 16:00 16:30 (326ВЊVFLHQWLВїFH[KLELWLRQ registration WHFKQLFDOH[KLELWLRQ 17:00 CC 1217 Cardiac Imaging ,PDJLQJWKH diseased myocardium (p. 71) CC 1216 Spinal Imaging and Intervention Spinal intervention: 'RHVLWKHOS" (p. 71) SA 12 State of the Art Symposium Stroke management DURXQGWKH clock (p. 72) RC 1210 Musculoskeletal Hip (p. 73) EВі 1220 Interactive Teaching Session /\PSKRPDV Diagnosis, staging and follow-up (p. 74) RC 1207 Genitourinary 7KHXWHUXV Imaging and intervention (p. 74) SF 12a Special Focus Session Occupational lung diseases (OLD) (p. 75) RC 1211 Neuro Brain tumors (p. 76) RC 1213 Physics in Radiology 3K\VLFVDQG WHFKQRORJ\RI multi-modality imaging systems (p. 76) RC 1212 Pediatric Best practice for imaging WKH*,*8 tracts (p. 77) 16:30 17:00 17:30 18:00 18:30 19:00 S244 11:30 12:30 SY 14 Philips Healthcare Satellite Symposium (p. 528) SY 13 Toshiba Satellite Symposium (p. 528) 13:30 18:30 11:00 12:00 12:30 18:00 09:30 10:00 10:00 17:30 09:00 19:00 A B C D E F G F H Scientific Sessions room L/M 1st level room N/O 1st level room P 1st level room Q 2nd level room R 1st level room U 2nd level room W 2nd level room X 1st level room Y 2nd level room Z 2nd level 07:00 07:00 07:30 07:30 08:00 08:00 08:30 09:00 09:30 08:30 RC 914 Radiographers Professional Issues/ Education (p. 65) MC 919 Advances in CT and MRI in Major Trauma Musculoskeletal trauma (p. 66) RC 903 Cardiac CT vs MRI (p. 67) RC 907 Genitourinary Percutaneous stone H[WUDFWLRQ 6XFFHVVE\ team work (p. 68) RC 901 Abdominal and Gastrointestinal Steatosis in liver imaging (p. 68) WS 921 Image-Guided Breast Biopsy: How to do it WS 923 Cardiac CT PostProcessing and Analysis WS 924 Functional Imaging of Tumors: How to do it 09:00 09:30 10:00 10:00 10:30 11:00 11:30 10:30 SS 1014 Radiographers Education and TXDOLW\FRQWURO (p. 261) SS 1011 Neuro Interventional and vascular imaging (p. 263) SY 10 Bracco Satellite Symposium (p. 527) SS 1009 Interventional Radiology Aortic and SHULSKHUDO interventions (p. 265) SS 1003 Cardiac Coronary DQJLRJUDSK\ 7HFKQLTXHV HIВїFLHQF\ outcome (p. 267) WS 1021 Image-Guided Breast Biopsy: How to do it WS 1022 Experience Vascular Procedures Using Simulators EIBIR (The European Institute for Biomedical Imaging Research) WS 1024 Functional Imaging of Tumors: How to do it 12:00 11:00 11:30 12:00 SY 15 SuperSonic Imagine Satellite Symposium (p. 528) 13:00 12:30 SY 16 Bracco Satellite Symposium (p. 528) 13:00 13:30 13:30 14:00 14:00 SY 21 Philips Healthcare Satellite Symposium (p. 530) 14:30 15:00 WS 1121 Image-Guided Breast Biopsy: How to do it WS 1122 Experience Vascular Procedures Using Simulators WS 1124 Functional Imaging of Tumors: How to do it 14:30 15:00 15:30 15:30 16:00 16:30 17:00 RC 1214 Radiographers Forensic imaging (p. 78) RC 1206 Molecular Imaging and Contrast Media US contrast agents (p. 79) RC 1204 Chest Computeraided diagnosis LQWKHFKHVW (p. 79) SF 12b Special Focus Session Interventional MRI (p. 80) 16:00 CC 1218 Breast: From Basics to Advanced Imaging Detection and FKDUDFWHULVDWLRQ RIEUHDVW OHVLRQVE\05, (p. 81) WS 1224 Functional Imaging of Tumors: How to do it 16:30 17:00 17:30 17:30 18:00 18:00 18:30 18:30 19:00 19:00 A B C D E F G H S245 Sunday 12:30 Scientific Sessions 10:30 - 12:00 Room B SS 1010 Knee and cartilage Moderators: G.M. Allen; Oxford/UK E.E. Drakonaki; Iraklion/GR 10:30 Multicenter trial of preoperative knee MRI: Variability of diagnostic effectiveness S.P. Morozov, S.K. Ternovoy, A.V. Korolev, P.A. Felisteev, J. Maryasheva, I. Smitienko; Moscow/RU ([email protected]) Purpose: To analyze variability of preoperative knee MRI by means of multiinstitutional study and to investigate limitations of the diagnostic method. Methods and Materials: The study included 200 patients who had had MRI performed at 4 independent diagnostic centers. All patients were arthroscopically operated by 1 orthopedic surgeon. Diagnostic effectiveness of MRI was analyzed for each intra-articular structure (6 cartilage regions, both menisci, both cruciate ligaments) with stratification by diagnostic centers. Analysis of variability was based on identification of objective (type of MR system, imaging protocol) and subjective (incorrect interpretation) limitations. Clinical decision rules were developed on the basis of cost-effectiveness analysis. Results: Analysis of combined data provided highest MRI accuracy for posterior cruciate ligament tears (94%), patello-femoral and lateral femoral condyle cartilage defects (85; 81%). Highest PPV (94%) was found for anterior cruciate ligament tear. Highest PPV was found for anterior cruciate ligament tears (94%) and medial femoral condyle cartilage defects (87%). Highest NPV was found for posterior cruciate ligament tears (99%) and patello-femoral cartilage defects (87%). The greatest variations of sensitivity were found for diagnosis of posterior cruciate ligament tear and lateral tibial condyle defects. The greatest variations of specificity were found for diagnosis of anterior cruciate ligament and menisci tears. Major reasons for low diagnostic effectiveness were incomplete imaging protocol and misinterpretation of MRI symptoms. Conclusion: Preoperative MRI of knee joint is characterized by high variability of diagnostic effectiveness. Standardized imaging protocol and correct interpretation of MRI symptoms are pre-requisites for including MRI into clinical decision rules. B-462 10:48 Evaluation of knee cartilage with MDCT arthrography: Morphological assessment, study on washout and comparison with arthroscopy B. Graca, A. Gil-Agostinho, A. Marques, F. Santos-Silva, A. Nascimento, F. Caseiro-Alves; Coimbra/PT ([email protected]) Musculoskeletal B-461 B-463 10:39 MRI of the knee: Does field strength influence diagnostic accuracy and interobserver correlation? W.W. Krampla, M. Roesel, K. Svoboda, A. Nachbagauer, M. Gschwantler, W.F. Hruby; Vienna/AT ([email protected]) Purpose: The accuracy of the reports are taken for granted when a patient is referred for an MRI of the knee. In this paper, the inter-observer variance regarding the interpretation of internal structures of the knee was subjected to statistical analysis while taking the field strength of the apparatus into account. Methods and Materials: A total of 52 MRI studies of knee joints (acquired at 1.0, 1.5 and 3 Tesla scanners) were interpreted by 11 radiologists independently. Their reports were compared and inter-observer variance was calculated. The findings were compared with the intraoperative situs. Specificity and sensitivity were evaluated in the meniscus, cartilage and anterior cruciate ligament for each field strength. Results: Inter-observer correlation (kappa) ranges between 0.313 for the retropatellar cartilage and 0.597 for tears in the posterior horn of the medial meniscus. The values do not increase with the field strength. The number of false positive and false negative reports are highly dependent on the observer and do not correlate strongly with the technical equipment. Sensitivity ranges from 10% for tears of the anterior horn of the lateral meniscus to 87% for lateral chondral defects. Conclusion: Inter-observer correlation is generally low, although the diagnostic criteria are defined. The use of the classification scheme is strongly observer dependent and should be standardized by uniform training. The individual experience of the radiologist is of higher importance than the field strength of the MRI scanner. Purpose: To evaluate the diagnostic accuracy of arthrography with multidetector computed tomography (arthro-MDCT) in detecting hyaline cartilage abnormalities of the knee joint, using diagnostic arthroscopy as the gold standard. To investigate enhancement washout in articular cartilage. Methods and Materials: Knee arthro-MDCT images prospectively obtained in 23 patients (age range, 16-75 years; 12 female, 11 male) were evaluated for cartilage lesions. Unenhanced MDCT was followed by enhanced MDCT immediately and 150 min after administration of intra-articular iodinated contrast. Two radiologists analyzed the presence of lesions and CT enhancement washout on the cartilage surfaces. The sensitivity and specificity of arthro-MDCT for cartilage lesions and the Spearman correlation coefficient between arthrographic and arthroscopic grading were determined. CT enhancement washout was compared in cartilage without and with lesion (grade 1 or higher). Statistical analysis was performed with the Student t test. Results: At arthro-MDCT, sensitivities and specificities ranged between 72 and 74% for the detection of grade 2 or higher cartilage lesions, and between 85 and 81% for the detection of grade 3 or higher cartilage lesions. Spearman correlation coefficients between arthro-MDCT and arthroscopic grading ranged between 0.454 and 0.851. Mean enhancement washout of abnormal cartilage was higher than that of normal cartilage (18.8 HU p 62.9 [sd] vs -4.2 HU p 56.5, respectively; p .05). Conclusion: Arthro-MDCT is a valuable method for the assessment of cartilage lesions of the entire knee. Abnormal cartilage exhibits greater washout of contrast material than normal cartilage. The evaluation of CT enhancement washout may contribute positively to the characterization of cartilage lesions. B-464 10:57 T1 (Gd) gives comparable information as delta T1 relaxation rate in dGEMRIC evaluation of cartilage repair tissue S. Trattnig1, D. Burstein2, P. Szomolanyi1, K. Pinker1, G.H. Welsch1, T.C. Mamisch3; 1 Vienna/AT, 2Boston, MA/US, 3Berne/CH ([email protected]) Purpose: To evaluate the relationship between T1 after intravenous (IV) contrast administration (T1 (Gd)) and $relaxation rate (subtraction of inverse relaxation time T1 after IV Gadolinium (T1 (Gd)) and native inverse relaxation time T1) in the dGEMRIC technique of articular cartilage repair tissue. Methods and Materials: Thirty MR examinations after matrix-associated autologous chondrocyte transplantation (MACT) of knee joint with different post-operative intervals were examined at 3 T. T1 mapping using a variable flip-angle 3D-GRE was performed before and after contrast administration (dGEMRIC). T1 (Gd) and $R1 were calculated for repair tissue and normal cartilage. MR exams were subdivided into three postoperative groups (24 months). Spearman correlation coefficients were calculated. Results: The correlation coefficients were highly significant between T1 (Gd) and $R1 for repair tissue (R: -969) and normal reference cartilage (R: -0.928). The correlation was highly significant for repair tissue in early, middle and late postoperative interval after surgery (R values: -0.986; -0.970 and -0.978). For both metrics, highly significant differences (P 0.01) between early follow-up and the two later groups for cartilage repair tissue were found. Conclusion: The high correlation between T1Gd and DR1 and the comparable conclusions reached utilizing either metric imply that T1 mapping before intravenous administration of MR contrast agent is not necessary for the evaluation of the repair tissue. This will help to reduce costs, inconvenience to the patients, simplify the examination procedure and make dGEMRIC more attractive for follow-up of patients after cartilage repair surgeries. B-465 11:06 Semiquantitative assessment of focal cartilage lesions of the knee: A comparison of fat-suppressed intermediate weighted fast spin echo and double echo steady state sequences at 3.0 T MRI F.W. Roemer1, C.K. Kwoh2, M. Hannon2, M.D. Crema1, C.E. Moore3, J.M. Jakicic2, S.M. Green2, Z. Dhina1, A. Guermazi1; 1Boston, MA/US, 2Pittsburgh, PA/US, 3 Houston, TX/US ([email protected]) Purpose: A multitude of dedicated cartilage sequences are available in modern MRI scanners, but it is unknown if these sequences are equally useful for semiquantitative scoring of focal defects. The aim of the study was to compare the assessment of focal cartilage damage using the double echo steady state (DESS)- and intermediate weighted fast spin echo (IW)-sequences on a 3.0 T MRI system. S246 A B C D E F G F H Scientific Sessions Methods and Materials: The JOG-study includes 177 subjects aged 35-65 with frequent knee pain and radiographic osteoarthritis. A 3.0 T MRI of both knees was performed at baseline. Cartilage status was scored according to the WORMS system using all the available five sequences. A total of 245 superficial or full-thickness focal defects were detected. In a consensus reading, the lesions were evaluated side by side using only the sagittal DESS- and IW-sequences. Lesion conspicuity was graded from 0-3. High or low signal changes adjacent to the defect were noted as present or absent and the sequence that depicted the lesion with the larger size was noted. Wilcoxon statistics were used to determine the differences between the two sequences. Results: Of the scorable lesions, 37 were in the medial tibio-femoral, 47 in the lateral tibio-femoral and 126 in the patello-femoral compartments. Conspicuity was superior for the IW sequence (P 0.001). The DESS sequence showed significantly more associated signal changes (P 0.001). The IW sequence depicted the focal lesions with larger size (P 0.001). Conclusion: The cartilage-dedicated DESS-sequence was inferior to the IWsequence in depicting the number and size of focal cartilage defects. More additional intrachondral signal changes were observed with the DESS, but the significance of this finding is unclear. B-466 11:15 MRI of retropatellar cartilage with 7T high resolution in volunteers and patients J.M. Theysohn1, O. Kraff1, S. Maderwald1, O. Bieri2, H.H. Quick1, M.E. Ladd1, S.C. Ladd1; 1Essen/DE, 2Basel/CH ([email protected]) B-467 11:24 MRI of the knee at 3 T - first clinical results with a highly resolved isotropic PD FS-weighted 3D-TSE-sequence M. Notohamiprodjo1, A. Horng1, M. Pietschmann1, W. Horger2, J. Park2, J. Raya Garcia del Olmo1, K.A. Herrmann1, M.F. Reiser1, C. Glaser1; 1Munich/DE, 2 Erlangen/DE ([email protected]) Purpose: To technically and clinically evaluate high-resolution knee-MRI at 3 T with an isotropic fat-saturated (FS) proton-density-weighted (PDw) 3D-TSEsequence. Methods and Materials: For technical evaluation the dominant knee of 10 healthy volunteers was examined with a sagittally oriented PD-FS 3D-TSEsequence (TR1200 ms/TE30 ms/voxel-size 0.53 mm3/acquisition-time 10:35 min) on a 3 T-scanner. 0.5, 1 and 2 mm thick multiplanar-reconstructions (MPRs) were performed in the three major planes. SNR, CNR and anatomical-detailvisualization (5-point-scale) were compared to high-resolution state-of-the-art 2D-TSE-sequences in 3 orthogonal planes (TR3200 ms/TE30 ms/voxel-size 0.36x0.36x3 mmВі/total acquisition-time 12:34 min). For clinical evaluation 60 patients with cartilage and meniscus pathologies were examined with the same techniques. Patient 3D-datasets were assessed using 1 mm-thick MPRs. 2 radiologists independently assessed detection of abnormalities and diagnostic confidence. Arthroscopic correlation was available for 18 patients. Statistical analysis was performed using 95%-confidence intervals, Wilcoxon-signed-rank-tests and Weighted-+. B-468 11:33 The association of prevalent medial meniscal mucoid degeneration and tears with cartilage loss in the medial tibiofemoral compartment over a 2-year period assessed with 3.0 T MRI M.D. Crema1, F.W. Roemer1, M.D. Marra1, A. Guermazi1, F. Eckstein2, M.-P. Hellio Le Graverand-Gastineau3, L. Li1, B.T. Wyman3, D.J. Hunter1; 1 Boston, MA/US, 2Salzburg/AT, 3New London, CT/US ([email protected]) Purpose: Mechanical impairment of the meniscus will alter the weight-bearing capacities of the joint and lead to damage to the articular surface. The aim of this study was to assess the association of different types of medial meniscal pathologies with cartilage loss in the medial tibiofemoral compartment. Methods and Materials: A total of 161 women with and without knee osteoarthritis participated in a longitudinal 24-month observational study. Sagittal and coronal spoiled gradient recalled acquisitions at steady state and sagittal T2-weighted fat-suppressed sequences were acquired. Four grades of meniscal lesions were assigned for the anterior horn, body and posterior horn: 0 (normal), 1 (mucoid degeneration), 2 (single tears), and 3 (complex tears/maceration). Cartilage morphometry was performed in different tibiofemoral subregions using segmentation and computation software. Multiple linear regression models (grade 0 as the reference group) were applied for the analysis with cartilage thickness loss as the outcome. The results were adjusted for age, BMI and medial meniscal extrusion. Results: Cartilage loss at follow-up in the medial tibia (0.04, P = 0.035) and the external medial tibia (0.068, P = 0.037) was significantly increased for compartments with grade 3 lesions only, compared to knees with non-pathologic menisci. Cartilage loss at the external medial tibia appears related to tears of the posterior horn (0.074, P = 0.025). Conclusion: The protective function of the meniscus appears to be preserved even in the presence of mucoid degeneration and/or single tears. Prevalent complex tears and meniscal maceration are associated with increased cartilage loss in the same compartment, especially at the posterior horn. B-469 11:42 Meniscal repair: MRI follow-up with clinical correlation A. AlcalГЎ-Galiano, B. Merry del Val, ГЃ. NГіvez, M. PГ©rez Atienza, J. Acosta, J. Ayala, M.J. ArgГјeso Chamorro; Coslada, Madrid/ES ([email protected]) Purpose: There are relatively few studies of imaging following meniscal repair, fewer with clinical correlation. Our purpose was to correlate postoperative appearance on conventional MR of sutured menisci with clinical findings. Methods and Materials: A total of 24 patients presenting longitudinal tears underwent arthroscopic repair, performed with resorbable arrows with “all-inside” technique, different sutures were added depending on the extension of tear (62 suture points total) from 2005 to 2008. Follow-up was with conventional MR and concurrent clinical examination; time since surgery was 6 months-3 years. Morphology and signal intensity were used to classify repaired menisci in 3 groups: group 0, normal or correctly healed; group I, signs not conclusive of retear; group II, failed healing or retear. Results: Seventeen cases (71%) are affected by medial meniscus and 7 (29%) by lateral meniscus. Eleven cases are affected by peripheral tears, 7 affecting body and posterior horn and 8 bucket-handle tears. In total, 58% are included in group 0, mostly peripheral tears of posterior horn, 41% in group I, and 8% in group II, both arthroscopically confirmed bucket-handle retears. Morphological and signal changes were significantly related to the extension of tear and number and type of sutures. Repaired bucket-handle tears displayed most evident signal alterations, “all-inside” resorbable devices produced subtle changes. All patients except 2 retears were clinically healed. Clinical correlation proved most helpful in group I. A B C D E F G H S247 Sunday Purpose: MRI plays a central role in the diagnosis of degenerative musculoskeletal diseases. The limitations in cartilage assessment at established magnetic field strengths of 1.5 T or 3 T, however, are well known. Detailed detection and classification of cartilage defects depend on high spatial resolution as well as high contrast between diseased and normal cartilage. We evaluated the potential benefit of 7T, compared to 1.5 T, in evaluating the retropatellar cartilage in volunteers and patients. Methods and Materials: Eight healthy volunteers and five patients with known retropatellar pathologies underwent PD/T2, MEDIC, DESS and SSFP (only 7T) at 1.5 (Avanto, 8-channel head coil) and 7T (Magnetom 7T, both Siemens Healthcare). The 7T sequences had been previously optimized with regard to spatial resolution and contrast (imaging time 8 min each). Volunteers were used to compare image quality at both field strengths and between three different transmit-receive coils (only at 7T). The best 7T coil with regard to SNR of the retropatellar cartilage was used in patients. Field strengths and sequences were graded based on cartilage details and visualization of pathologies (three-point scale). Results: Imaging with 7T provided higher resolution (0.35 x 0.35 mmВІ in-plane). SNR of the retropatellar cartilage at 7T was highest for the loop coil (SNR gain 1.8-3.6 in MEDIC, DESS and SSFP compared to the second best coil). Cartilage detail and pathology depiction were graded to be higher at 7T. PD/T2 coverage at 7T was limited by SAR. Conclusion: Depiction of cartilage structures and pathologies is improved at 7T. Imaging at 7T will add supplementary information to established field strengths for cartilage pathology, especially if dedicated coils are used. Results: Compared to 2D-TSE 1 mm-thick 3D-TSE-MPRs provided comparable SNR and CNR and superior visualization of small structures such as meniscalroots (3D-TSE:4.9p0.1; 2D-TSE:4.4p0.3; p 0.05). Arthroscopic correlation showed no significant differences between 2D- and 3D-sequences. One reader detected significantly more cartilage-abnormalities with the 2D-TSE-sequence (3D-TSE:133; 2D-TSE:151; p 0.05). Diagnostic confidence for Grade-III-meniscus-lesions was significantly higher in 3D-TSE for one reader (3D-TSE:4.88p0.34; 2DTSE:4.34.p0.94; p 0.05). Otherwise there were no significant differences regarding detection of abnormalities and diagnostic confidence. Intersequence-correlation was excellent (0.82-0.92), interreader-correlation good to excellent (0.71-0.80) and not significantly different for both sequences. Conclusion: 3 T enables time-efficient 3D-TSE-imaging of the knee at adequate SNR and CNR with excellent anatomical-detail-visualization. Detection and visualization of meniscus- and cartilage-pathologies is at least comparable to stateof-the-art 2D-TSE-sequences. 3D-TSE-sequences with consecutive MPR may become a valuable component of future knee-MRI protocols. Scientific Sessions Conclusion: Although still a challenge, there is high overall accuracy of MR evaluation of postoperative menisci considering both morphology and signal intensity, especially correlating image findings with clinical evaluation. MR also serves to evaluate concomitant complications. B-470 11:51 The relationship of high-riding Wrisberg ligament to complete discoid lateral meniscus J. Kim, S.-H. Choi, J. Kwon, G. Ahn, J. Hwang; Seoul/KR Purpose: To evaluate whether the high-riding Wrisberg ligament (HRWL) on complete discoid lateral meniscus (CDLM) causes the lateral meniscus tear (LMT) often. Methods and Materials: Among 4149 knee MR, 101 knees MR imaging had CDLM. One hundred twenty-one non-discoid lateral meniscus (NDLM) cases were enrolled as the control group. All patients had performed arthroscopic surgery for any kinds of intraarticular derangements (ID). The presence of the Wrisberg ligament (WL) and the attachment level of the WL on medial femoral condyle (high-riding Wrisberg ligament (HRWL), low-riding Wisberg ligament (LRWL)) were evaluated. The relationship between the incidence of ID and the attachment level of the WL on medial femoral condyle of CDLM and NDLM was analyzed. Results: One hundred forty-one patients had WL: 73 patients (35 LRWL, 38 HRWL) in CDLM and 68 (59 LRWL, 9 HRWL) in NDLM. There were fifty-four LMT in 141 Wrisberg (+) group and 23 LMT in 81 Wrisberg (-) group regardless of the shape of lateral meniscus. The WL only was not a significant factor for causing the LMT (P=0.14). There were twenty LMT on LRWL and 21 HRWL on CDLM, 8 LRWL and 5 HRWL on NDLM. The LMT was forty-one on CDLM and 13 on NDLM. LMT were more common in CDLM (P 0.001). The coexistence of HRWL and CDLM was the significant factor for causing the LMT (P=0.0173) by multiple logistic regression. Conclusion: The coexistence of HRWL and CDLM was a significant factor in causing the LMT. 10:30 - 12:00 Room C GI Tract SS 1001a Rectal cancer: MRI Moderators: C. Savoye-Collet; Rouen/FR S.O. SchГ¶nberg; Mannheim/DE B-471 10:30 Accuracy of USPIO-enhanced MRI for staging of rectal cancer: A multicenter study in expert and 3 regional centers M. Maas1, G.L. Beets1, M.J. Lahaye1, S.M.E. Engelen1, J.P.M. Dohmen2, G.R.J. Opdenakker3, D.M.J. Lambregts1, J.E. Wildberger1, R.G.H. Beets-Tan 1; 1 Maastricht/NL, 2Weert/NL, 3Roermond/NL ([email protected]) Purpose: Ultrasmall superparamagnetic particle ironoxide (USPIO) MRI is known to have high accuracy for predicting nodal metastases in various cancers. This prospective study evaluates diagnostic performance of MRI for predicting T-stage and N-stage with and without USPIO in primary non locally-advanced rectal cancer in both general and expert centers. Methods and Materials: From February 2003 to October 2007, 327 rectal cancer patients received USPIO-MRI 24 hours after infusion. Sequences were axial 2DT2WFSE, 3DT1WGRE & 3DT2*. Local radiologists predicted T-stage and N-stage, first on T2W, thereafter on USPIO-3DT2*. Separately, the expert double read each MR, on which selection for treatment occurred. Reference standard was histology. ROC-analysis for prediction of tumours limited to the bowel wall (pT1-2) and nodal involvement were performed. Interobserver agreement analyses were performed. Results: 130/327 were non locally-advanced patients and used for analysis (42/130 regional inclusions, 42/130 pN+). For T-stage PPV and NPV for non-experts were 87% and 67%, for experts 95 and 69%. For N-stage PPV and NPV for non-experts were 62 and 87%, for experts 47 and 92%. With USPIO PPV and NPV for N-stage were 57 and 95% for non-experts and 70 and 97% for experts. Conclusion: 1. MRI can predict tumors limited to the bowel wall (pT1-2) with high PPV for expert as well as non-experts, however, at the expense of NPV. 2. T2Wsequences (without USPIO) for nodal staging are insufficient for clinical decision making unless read by an expert. 3. Use of USPIO-3DT2* improved diagnostic performance for both expert and regional radiologists towards accurate selection of pN0. S248 A B C D E F G F H B-472 10:39 Diagnostic performance of USPIO-enhanced MRI for nodal staging in primary rectal cancer is dependent on the number of lymph nodes harvested at histology M. Maas, D.M.J. Lambregts, M.J. Lahaye, A.P. de BruГЇne, G.L. Beets, J.E. Wildberger, R.G.H. Beets-Tan; Maastricht/NL ([email protected]) Purpose: Nodal involvement in rectal cancer indicates poor prognosis. Preoperative knowledge of nodes could impact treatment choice. However nodal staging at histology is also associated with prognosis. 12-16 nodes are defined as “good harvesting”, less as “bad harvesting”. As part of a multicenter study accuracy of USPIO-MRI as a stratification tool for treatment of rectal cancer was evaluated. This study aims to assess whether there is difference in performance of USPIO-MRI with good vs bad node-harvesting. Methods and Materials: 117 primary rectal cancer patients were evaluated retrospectively. All patients underwent USPIO-enhanced MRI followed by TME. An expert reader predicted nodal status by USPIO-MRI using a confidence level score (0=definitely N- to 4= definitely N+), with histology as reference standard. Patients were categorised according to the number of lymph nodes harvested at histology (group 1=0-4 nodes, 2=4-8 nodes, 3=8-12 nodes, 4=12-16 nodes, 5=16-20 nodes, 6=/= 20 nodes). ROC-curve analyses were performed for the 6 groups. Results: AUC for group 1 (n=9) was 0.643, for group 2 (n=29) 0.830, for group 3 (n=32) 0.833, for group 4 (n=27) 0.917, for group 5 (n=12) 0.857, and for group 6 (n=8) 1.00. Conclusion: 1. Diagnostic performance of USPIO-MRI for nodal staging in rectal cancer increases with increasing number of nodes harvested at histology. 2. Best MR performance correlates with AUC of groups 4-6, confirming that optimal number of harvested nodes should be recommended = 12. 3. In case of suboptimal histological nodal staging (4-12 harvested nodes), nodal staging with USPIO-enhanced MRI would be more reliable for clinical decision making. B-473 10:48 Accuracy of Gadofosveset-enhanced MRI for predicting nodal status in primary rectal cancer D.M.J. Lambregts, G.L. Beets, A.G. Kessels, M.J. Lahaye, S.M.E. Engelen, M. Maas, A.P. de BruГЇne, J.E. Wildberger, R.G.H. Beets-Tan; Maastricht/NL ([email protected]) Purpose: Nodal involvement indicates poor prognosis in rectal cancer. Accurate assessment of nodes with MRI could allow tailored treatment according to individual risk. Our goal was to validate gadolinium-based contrast (Gadofosveset)-enhanced MRI for prediction of nodal status in primary rectal cancer patients. Methods and Materials: A total of 32 rectal cancer patients underwent MRI including T2W FSE (T2W) and Gadofosveset-enhanced T1W GRE. Patients were stratified into three treatment groups: total mesorectal excision (TME; n = 5), TME with neoadjuvant radiotherapy (n =1 0) and TME with neoadjuvant chemoradiation (CRT; n = 17). The latter underwent a second MRI post-CRT with additional assessment thereafter. An experienced reader predicted each node for benign or malignant on T2W and Gadofosveset-enhanced images respectively using a confidence level score (0=definitely benign, 1=probably benign, 2=possibly malignant, 3=probably malignant, 4=definitely malignant). Nodes were recorded on an anatomic map, used as a template for lesion by lesion comparison with histology. Receiver operator characteristics (ROC) curve-analyses were performed to compare diagnostic performance. Results: In 32 patients, 208 nodes were analysed, of which 47 positives in 14 patients. 44/47 positive nodes were predicted correctly on Gadofosveset-enhanced MRI. Per lesion sensitivity was 93%, specificity 96%, PPV 88% and NPV 98%. Area under the ROC-curve (AUC) for Gadofosveset-enhanced imaging was better than for T2W imaging (0.979 vs 0.813, p 0.001). Per patient sensitivity was 93%, specificity 89%, PPV 87%, NPV 94% and AUC 0.917. Conclusion: Although larger multicenter studies are needed to confirm our results, Gadofosveset-enhanced MRI is accurate and promising for prediction of metastatic nodes in rectal cancer patients. B-474 10:57 Diffusion-weighted imaging assessment of lymph node metastasis in pelvis Y. Liang, E. Jin, Y. Zhang, W. He; Beijing/CN ([email protected]) Purpose: The goal of this study is to compare the routine MRI (T1WI and T2WI) and combined routine MRI with diffusion-weighted imaging (DWI) in the detection of lymph node metastasis in pelvis. Methods and Materials: A total of 53 patients with malignant tumor in pelvis who underwent MRI for local staging and received radical tumor excision soon after MRI were enrolled in the study. MRI transverse fat suppression T2WI, T1WI, dynamic Scientific Sessions enhanced T1WI and DWI (b = 1000 s/mm2) were performed using a 8-channel coil at a 3 T in all patients. The scan time of DWI is 1 m and 58 s. Tumor spectrum in the study included rectal adenocarcinoma (37 patients), rectal lymphoma (1 case), rectal carcinoid (1 case), prostate adenocarcinoma (9 patients) and endometrial caner (5 patients). Based on the pathologic result, the ability in the detection of lymphadenopathy in pelvis was compared between routine MRI sequences and routine sequences plus DWI. Results: Pelvis lymph node metastasis was found in 39 patients (73.6%) by pathology from excisional specimen and total 137 lymph nodes ranging from 0.2-1.3 cm were involved in cancer. Abnormal signal change on DWI was detected within tumor areas in 50 patients (94.3%). Lymph node metastasis had same signal change as primary tumor on DWI. The sensitivity and specificity for routine MRI in the detection of lymph node metastasis were 84 and 65%, while routine MRI combined DWI were 83 and 81%. Conclusion: DWI could help to detect the small lymph node metastasis in pelvis. Routine MRI combined with DWI may increase the accuracy of local tumor stage. B-475 11:06 Appearance of non-metastatic pelvic lymph nodes at diffusion-weighted imaging: A quantitative evaluation of apparent diffusion coefficient values P. Paolantonio1, R. Ferrari1, M. Rengo1, F. Vecchietti1, P. Lucchesi1, F. Vasselli2, A. Laghi1; 1Latina/IT, 2Rome/IT ([email protected]) B-476 11:15 Diffusion-weighted MRI for the diagnosis of rectal carcinoma: Preliminary results of a prospective study G. Engin, R. Sharifov, M. Gulluoglu, Y. Kapran, E. Balik, S. Yamaner; Istanbul/TR ([email protected]) Purpose: To evaluate the clinical value of diffusion-weighted magnetic resonance imaging (DW-MRI) to diagnose the primary carcinoma of rectum by measuring tumor and normal rectal wall apparent diffusion coefficient (ADC). Methods and Materials: Thirty-two cases, who had been histopathologically diagnosed as adenocarcinoma were evaluated with MRI prior to the treatment. MRI was applied with 1.5-Tesla MR (Symhony, Siemens Medical Solutions, Erlangen, Germany) instrument and pelvic phase array coil. DW-MRI was applied in all patients along with standard TSE imaging. TSE imaging was applied to T1W axial, T2W axial, sagittal and oblique coronal planes. In DW-MRI, inversion recovery echo-planar images (“IR” EPG) were obtained. B values were taken as 50, 400, 800 sn/mmВІ and ADC maps images were obtained. The mean ADC of tumor and normal appearing rectal wall was obtained using region of interest (“ROI”) in ADC maps images. Results: Mean ADC values obtained from rectal tumor and normal appearing rectal wall were found as 0.77 p 0.14 (range 0.58-1.16) x 10Ві mmВІ/sc ve 1.71 p 0.18 (range 1.31-2.03) x 10Ві mmВІ/sc, respectively. Statistically significant difference was found between these values (p 0.001). Furthermore, DW-MR images were found useful in distinguishing tumor from normal rectal wall. Conclusion: DW-MRI can contribute to TSE imaging in tumor diagnosis and border determination. 11:24 Evaluation of image quality and CNR values between 1.5 T and 3 T in rectal cancer J. Pernas, D. Hernandez, J. Otero, J. Monill, C. Perez, M. Menso; Barcelona/ES ([email protected]) Purpose: To compare the results of 1.5 T vs 3 T regarding the overall image quality, contrast to noise ratio (CNR), normal anatomic structures depiction and tumor and lymph nodes delineation in patients with rectal neoplasm. Methods and Materials: 40 patients with proven rectal cancer underwent pelvic MR. They were randomized 20 at 3.0 T/20 at 1.5T. The pelvis, using superficial coil, was imaged with T1WI in axial plane and T2WI in axial, coronal and saggital planes following the same imaging protocol. CNR was measured in T2WI axial at rectal tumor vs perirectal fat. The images were analysed retrospectively by three independent observers unaware of which MR machine was used. The overall image quality and other parameters regarding tumor and lymph nodes delineation and normal anatomic structures were evaluated using a consensuated grade scale (1-5). Results: Overall image quality was 1.7/5 for the 1.5 T and 3.7/5 for the 3 T. Scale grade artifact scored 1.8/5 for the 1.5 T and 2.2/5 for the 3 T. Discrimination between the signal of the tumor vs normal rectal wall scored 1.9/5 for the 1.5 T and 3/5 for the 3 T. Lymph nodes delineation scored 1.8/5 for the 1.5 T and 2.1/5 for the 3 T. CNR was 35.3 for the 1.5 T and 49.09 for the 3 T. Conclusion: 3 T obtained better overall image quality than 1.5 T in the depiction of the tumor, although a higher number of artifacts in the upper part of the pelvis were found in the 3 TMR. No significant differences were found regarding tumor and lymph nodes delineation, normal anatomic structures depiction and CNR. B-478 11:33 Whole-body MRI at 1.5 and 3 Tesla compared to FDG-PET-CT for the detection of tumor recurrence in patients with colorectal cancer G.P. Schmidt, A. Baur-Melnyk, J. Lutz, A. Haug, C.R. Becker, M.F. Reiser, K.A. Herrmann; Munich/DE ([email protected]) Purpose: To assess the diagnostic accuracy of whole body-MRI (WB-MRI) at 1.5 and 3 Tesla compared to FDG-PET-CT in the follow-up of patients suffering from colorectal cancer. Methods and Materials: 24 patients with a history of colorectal cancer and suspicion of tumor recurrence underwent FDG-PET-CT and WB-MRI at 1.5 (n=14) or 3 Tesla (n=10). Coronal T1w-TSE- and STIR-sequences at four body levels, HASTE-imaging of the lungs, T2w-TSE and contrast-enhanced T1w-sequences of the liver, brain, abdomen and pelvis were performed. Local recurrence, lymph node involvement and distant metastatic disease were assessed using radiological follow-up within 6 months as standard of reference. Results: 77 malignant foci in 17/24 patients were detected with WB-MRI and PETCT. Both modalities concordantly revealed 2 local recurrent tumors. PET-CT detected more lymph node metastases (sensitivity 93%, n=27/29) than WB-MRI (sensitivity 63%, n=18/29). PET-CT and WB-MRI achieved similar sensitivity for the detection of organ metastases with 80 and 78% (37/46 and 36/46). WB-MRI detected brain metastases in 1 patient, 1 false-positive local recurrence was indicated by PET-CT. Overall diagnostic accuracy for PET-CT was 91 and 83% for WB-MRI. Examination time for WB-MRI at 1.5 and 3 T was 52 and 43 min. Conclusion: FDG-PET-CT is the method of choice for integrated tumor imaging in the follow-up of colorectal cancer, especially for the diagnosis of lymph node metastases. WB-MRI is useful for the detection of organ metastases, especially to the liver, bone and brain. WB-MRI at 3 Tesla is feasible and provides overall scan time reduction at constant image resolution. B-479 11:42 Rectal carcinoma: MR imaging features with pathologic correlation before and after chemoradiation therapy V. Di Giacomo, R. Del Vescovo, I. Sansoni, L. Trodella, R. Grasso, L. Trodella, B. Beomonte Zobel; Rome/IT Purpose: To evaluate the extent and imaging appearance of rectal carcinoma before and after chemoradiation therapy using magnetic resonance imaging and to correlate the post-treatment MR imaging appearance with pathologic findings after surgical excision. Methods and Materials: A preoperative MRI in 20 patients with locally advanced adenocarcinoma of rectum was performed before and after a 5-week course of chemoradiation therapy. The protocol included turbo spin-echo T2-weighted MR imaging and spin-echo T1-weighted MR imaging with and without fat suppression. Post contrast T1-weighted sequences with fat suppression were also employed. Primary tumor and nodal involvement were evaluated by preoperative MR before A B C D E F G H S249 Sunday Purpose: To evaluate the appearance and conspicutity of non-metastatic pelvic lymph nodes at diffusion-weighted imaging (DWI) and to assess the range of apparent diffusion coefficient (ADC) values in healthy volunteers. Methods and Materials: A total of 40 healthy volunteers ranging in age between 23 and 45 years were included. All subjects underwent MR scan of the pelvis on a 1.5 T MR platform (Signa Hde; GE, USA). A TSE T2W sequence (TR: 4,500 msec; TE: 190 msec; matrix: 512 x 256; slice thickness 4 mm; Nex 4) and an SE-EPI-DWI sequence (TR 9,000 msec; TE: 87 msec; matrix 128 x 128; Fov 350 x 350 mm; slice thickness 5 mm; Nex 8 acq. time: 2 min 50 sec; b values: 0-1000) were acquired; ADC values were calculated on a per pixel basis. Image analysis was performed by two radiologists in consensus. A node-by-node matching comparison was performed between TSE T2W and b-1000 DW images. CNR between lymph node and adipose tissue on both TSE T2W images and b 100DW were compared using non-parametric Wilcoxon test (P 0.0001). For each node, the ADC value was measured using an ROI. Results: A total of 423 lymph nodes were recognized with minimum diameter ranging between 3.5 and 9.5 mm. A node-by-node matching between DWI sequence and TSE T2W images was possible for each lymph node. Lymph node CNR was significantly higher on heavy DWI with respect to TSE T2W images. The values of ADC were as follows: mean, 2.01 (DS 0.3) x 10-3 mm2/sec. Conclusion: Non-metastatic lymph nodes show high signal intensity on heavy DW images and are clearly identifiable, thanks to high conspicuity, with respect to surrounding tissues and structures. Mean ADC value of non-metastatic lymph node in our series was 2.01 (DS 0.3) x 10-3 mm2/sec. B-477 Scientific Sessions and after chemoradiation therapy: morphologic changes and nodal downstaging were recorded. Pathologic findings of resected tumors were compared to posttreatment MR imaging appearance to evaluate the accuracy of MR in the prediction of tumor stage, nodal downstaging and distance between tumor and circumferential resection margin. Results: Tumor shrinkage 30% was found in 10 (53%; 90% CI, 56-70%) of 20 patients; changes in MRI T stage occurred in 6 (15%; 90% CI, 5-25%) of 20 patients. All cases of tumor regression from the circumferential resection margin were found and confirmed at histologic examination. Nodal downstaging was observed in 10 (67%; 89% CI, 50-79%) of 17 patients. Conclusion: Our results suggest that MR imaging could be a useful diagnostic tool in the preoperative assessment of tumor size and nodal downstaging after chemoradiation therapy in patients with rectal carcinoma. The distance between tumor and circumferential resection margin can be assessed by MR with good accuracy. B-480 11:51 Can magnetic resonance imaging detect complete response after downsizing chemoradiotherapy for rectal cancer? M. Anderson, M. Betts, A. Slater, F.V. Gleeson; Oxford/UK ([email protected]) Purpose: To evaluate the utility of MRI to detect complete tumour response and differentiate from other responses. Methods and Materials: 30 patients with rectal cancer treated by downsizing CRT were selected from a pathological database to include approximately half complete or near (T2) complete response. Imaging was carried out on a 1.5 T scanner. Two experienced observers reported the studies independently. The tumour and nodal status was assessed. Response to chemotherapy was assessed on a five point scale, from disease progression to complete response. Histopathology was used as the reference standard. Sensitivity, specificity and accuracy were calculated. The agreement between radiological response and pathology was assessed with Cohen’s Kappa. Results: After CRT, there was T0 tumour in 23% (n=7/30) and T2 tumour in 20% (n=6/30). From comparison of pretreatment scan to pathology 26% (n=8/30) showed no response and 10% (n=3/30) had progressed. The sensitivity and specificity and accuracy for detecting T0 was 55, 76 and 70%, respectively, for observer 1 and 33, 62 and 33% for observer 2. Whilst there was excellent agreement between the observers for the T staging, kappa= 0.602, the agreement of each observer with pathology was poor, k= 0.31 and 0.27. There was good agreement in the assessment of progression, stable disease or partial response, with k= 0.5 and 0.56. Conclusion: MRI is unable to reliably detect T0 post CRT and cannot consistently distinguish this from T2 tumours. It is able to more accurately detect disease progression, stable disease or partial response. 10:30 - 12:00 Room F1 Genitourinary SS 1007 Imaging of prostate cancer Moderators: L. Pallwein; Innsbruck/AT A. Zubarev; Moscow/RU B-481 10:30 Multimodality imaging of prostate cancer J. Grimm, V. Ponomarev, P. Gregor, P. Brader, H. Hricak; New York, NY/US ([email protected]) Purpose: Prostate-specific membrane antigen (PSMA) is expressed on prostate cancer cells and correlating with disease aggressiveness. This antigen evoked interest as predictor for progression of prostate cancer since highest levels are seen in metastatic and higher-grade disease. Imaging of PSMA could therefore be very useful in detection and characterization of prostate cancer. For this purpose, we developed probes for multimodality imaging of PSMA. Methods and Materials: In silico modeling of phage-derived peptides binding to PSMA was performed to evaluate binding. Peptides were attached to magnetofluorescent nanoparticles. Binding to PSMA-expressing cells (LNCAP) was evaluated utilizing FACS. Mice bearing LNCAP and PC3 (PSMA-negative) tumors were injected with probe. Optical tomography and MR imaging was performed 24 hours later. A nonspecific intravascular optical probe (Angiosense, VISEN) was used to normalize for tumor vascularity. S250 A B C D E F G F H Results: Specific binding of the peptide was confirmed by incubating FITC-labeled peptide with LNCAP or PC3 cells at various concentrations. Increasing binding to LNCAP cells was observed with rising peptide concentration while binding to PC3 cells never exceeded the background. In vivo optical imaging revealed 8-times higher binding to the PSMA-expressing tumor as compared to control tumor. On MRI the T2 relaxation time was markedly lower in the PSMA-expressing tumor (DT2 of 28p9 ms). Histology confirmed the targeting of the particles to the PSMAexpressing tumor cells. Conclusion: A nanocompound probe for multimodality imaging of prostate cancer was developed. This probe allowed specific detection of PSMA-expressing tumors in vitro and in vivo and can be utilized to further characterize prostate cancer. B-482 10:39 Detection of prostate cancer with contrast-enhanced ultrasonographic micro-flow imaging: Comparison with conventional ultrasonography F. Li, S. Xie, J. Xia, J. Du, H. Li; Shanghai/CN Purpose: To evaluate the value of contrast-enhanced ultrasonography in detecting prostate cancer using micro-flow imaging (MFI) compared with conventional ultrasonography. Methods and Materials: A total of 65 patients with serum prostate- specific antigen levels higher than 4.00 ng/ml (4.01-86.94) were evaluated with transrectal grayscale, power Doppler, MFI ultrasonography examinations and then sonographically guided biopsy. MFI was performed using contrast agent SonoVue. Biopsy was performed at 12 sites of the base, the mid gland and the apex in each patient. When any of the three methods showed abnormality, the biopsy site was directed to the abnormal foci. Diagnostic efficiency of the three methods for prostate cancer detection was compared based on biopsy results according to the patient and biopsy site. Results: Overall, prostate cancer was detected in 230 (29.4%) of 780 specimens in 36 (55.3%) of 65 patients. MFI could detect more patients than gray-scale and power Doppler (P = 0.021 and P = 0.031, respectively); 6 (16.7%) of the 36 patients diagnosed with cancer were identified only by MFI. Based on the biopsy site, MFI had higher sensitivity and overall accuracy (80.0 and 83.1%) than gray-scale (46.9 and 76.8%) and power Doppler (37.4 and 74.6%) ultrasonography (P = 0.004 and P 0.001, respectively; P = 0.001 and P 0.001, respectively), while the specificity of MFI was 84.3%, lower than 89.3% for gray-scale and 90.2% for power Doppler ultrasonography (P = 0.004 and P 0.001, respectively). Conclusion: Based on the biopsy site, MFI could detect more prostate cancer patients and improve sensitivity and overall accuracy than conventional ultrasonography. B-483 10:48 Usefulness of a 3D T2-weighted turbo-spin-echosequence (VISTA) at 3 Tesla for a complete morphologic assessment of prostatic carcinoma: One-stop shop study C. Roy, A. Matau, G. Bierry, T. Charles, H. Lang; Strasbourg/FR ([email protected]) Purpose: To prospectively evaluate 3D T2wTSE sequence (VISTA) by comparison with multiple 2D T2w-T1w TSE for a complete morphologic prostatic carcinoma assessment. Methods and Materials: A total of 47 patients were examined for prostatic carcinoma staging at 3.0 T (Achieva, Philips) with a standard set including three orientations 2D T2wTSE (4,862 ms/80 ms, endorectal coil, 0.6 Г— 0.7 Г— 3.00 mm3, 4:42 min; axial T1wTSE (5 mm, 3:30 min) and 3DTSE (VISTA) TR/TE/FA : 2,113/200/120, 0.9 Г— 0.9 Г— 1.1 mm3, 4 : 58 min pelvic coil). Fat, peripheral zone, tumor SNR, as well as tumor-peripheral zone CNR were measured from ROI. Two radiologists correlated 3D VISTA with 2D rated image quality with contrast-ratio impression, signal homogeneity and artefacts, as well as prostatic capsule and lymph node visualization. Results: Fat, peripheral zone, capsule SNR and tumor-peripheral zone CNR were higher with 3D VISTA (774, 845, 168, 655 p 11) compared with 2DTSE (627, 490, 136, 446 p 15), respectively. Higher contrast images provided a perfect visualization of the prostatic capsule. Image quality, CNR and homogeneity of transverse,coronal and oblique orientations rated higher for VISTA than for 2D, but lower for the sagittal view (P 0.05). Minor flow artefacts did not alter the diagnostic confidence. Lymph nodes assessment was clearly better for shape and vessels differentiation. Interactive 3D MPR software toll providing multiplanar views was essential. Conclusion: At 3 T, a unique VISTA sequence with wide coverage and high contrast multiplanar images makes a confident evaluation of tumor-prostatic capsule, as well as survey of lymph nodes. It makes multiple 2D acquisitions unnecessary. Scientific Sessions B-484 10:57 Predictive value of digital rectal examination, prostate-specific antigen and combined MRI and MR spectroscopy of the prostate for results of subsequent biopsy in patients with previously negative prostate biopsy U.G. Mueller-Lisse, U.L. Mueller-Lisse, M. Seitz, C. Stief, M.F. Reiser, M.K. Scherr; Munich/DE ([email protected]) Purpose: To assess predictive values for results of subsequent prostate biopsy of combined MRI and MR spectroscopy of the prostate (MRI + MRS), digital rectal examination (DRE), and prostate-specific antigen (PSA) in patients with suspected prostate cancer (PCA) and previously negative prostate biopsy (pnpbx). Methods and Materials: Among 499 patients who underwent MRI + MRS with an endorectal-coil-body-phased-array-coil system at 1.5 T between 05/2003 and 04/2007, cases with suspicion of PCA at DRE or PSA ( 4 ng/ml), no previous treatment, pnpbx, and subsequent prostate biopsy in our institution were retrospectively analyzed. Results: Among 42 patients (age, 64p6 years, PSA 11.0p6.7 ng/ml, 2p1 pnpbx), subsequent prostate biopsy revealed PCA in 12 (29%, Gleason sum, 6p1). Respective positive and negative predictive values for PCA at subsequent biopsy were 6/14 (43%) and 22/28 (79%) for DRE, 6/18 (33%) and 18/24 (75%) for PSA (cut-off, 10 ng/ml), 12/32 (38%) and 10/10 (100%) for MRI + MRS, and 11/14 (79%) and 27/28 (96%) for MRI + MRS with signs of PCA in the peripheral zone of more than one half prostate sextant. Conclusion: After negative prostate biopsy, MRI + MRS may detect both patients who would not benefit from another biopsy and patients whose next biopsy is highly likely to show PCA. B-485 11:06 Assessing combination of diffusion coefficients, metabolic profiles and vascular maps on magnetic resonance imaging for prostate cancer detection S.F. Riches1, V.A. Morgan1, S. Sandhu1, C. Fisher2, G.S. Payne1, M. Germuska1, D.J. Collins1, A. Thompson2, N.M. deSouza1; 1Sutton Surrey/UK, 2London/UK ([email protected]) B-486 11:15 Improved detection of prostate carcinoma by integration of six different MR methodologies at 1.5 T K. Engelhard1, H.-P. Hollenbach2, D. Engehausen1; 1NГјrnberg/DE, 2Erlangen/DE ([email protected]) Purpose: To determine the diagnostic valency of an optimized diagnostic MRprogram in detecting prostate cancer. Methods and Materials: 24 patients with elevated PSA levels (PSA 4 ng/ml) underwent endorectal MRI in a 1.5 T scanner (Magnetom Espree, Siemens Medical Solution Erlangen, Germany). Six different imaging techniques were applied. The program comprised T2-weighted (T2w) protocols, T2/T2*-mapping protocols, a EP- B-487 11:24 Clinical significance of endorectal MR in prostate cancer patients for nerve sparing radical prostatectomy: Retrospective analysis in 386 patients H.-P. Schlemmer, M. Mlynczak, M. Rothke, M.P. Lichy, U. Vogel, D. Schilling, A. Stenzl, C.D. Claussen; TГјbingen/DE Purpose: To evaluate the clinical significance of standardized high-spatial resolution T2w endorectal MRI in patients with prostate cancer for planning nerve sparing radical prostatectomy. Methods and Materials: In total, 386 patients with biopsy-proven prostate cancer (mean age 62.7 years) were included who all underwent standardized endorectal MRI before radical prostatectomy (mean time interval 13 days). MR examinations were performed at 1.5 T using a commercial available endorectal and body phased array coil. Standardized high-resolution transverse and coronal T2w TSE sequences were applied and evaluated by experienced radiologists in clinical routine applying conventional imaging criteria. Radiological and histopathological reports were retrospectively compared and analysed including data of PSA, Gleason score and grading. Results: Mean value of PSA serum level was 8.9 ng/ml, pathologic Gleason Score 6.7 and of Grading 2.3. Organ-confined disease was found by pathology in 267 patients (69%). In total, 82% of these patients had multifocal tumors involving both lobes (stage T2c). Nerve sparing for at least on side of the prostate could be achieved in 78% of the patients. Positive predictive value of MR for organ-confined disease (extracapsular extension) was 78% (71%). Bilateral (unilateral) nerve sparing was achieved in 46% (32%) of the patients in case when MR described organ-confined disease whereas in 31% (46%) of the patients when MR discribed extracapsular extension. Conclusion: Most of surgical candidates present with multifocal tumors involving both lobes of the prostate. Endorectal MRI is an useful predictor for extracapsular tumor extension and positively influences the success of bilateral nerve-sparing surgery. B-488 11:33 Contrast-enhanced colour Doppler-targeted prostate biopsy for prostate cancer detection: Results of 2,008 men L. Pallwein, F. Aigner, W. Jaschke, V. Spiss, M. Mitterberger, F. Frauscher; Innsbruck/AT Purpose: To compare the prostate cancer detection rate of contrast-enhanced colour Doppler ultrasound-targeted biopsy with grayscale US-guided systematic biopsy in a series of 2,008 men. Methods and Materials: In a 4-year period, 2,008 male screening volunteers with a total prostate-specific antigen of 1.25 ng./ml. or greater and free-to-total prostatespecific antigen less than 18% were included. Mean patient age was 60 +- 9.3 years and mean PSA value was 6.5 +- 14.7 ng/ml. Two independent examiners evaluated each patient and a single investigator performed five or fewer contrast-enhanced targeted biopsies into the hypervascular regions in the peripheral zone during intravenous infusion of the US contrast agent SonoVue. Subsequently, another examiner performed ten systematic prostate biopsies. The cancer detection rates of the two techniques were compared. Results: Overall, cancer was detected in 559 patients (28%), including 476 (24%) by contrast-enhanced targeted biopsy and in 410 (20%) by systematic biopsy. Cancer was detected by targeted biopsy alone in 149 patients (27%) and by systematic A B C D E F G H S251 Sunday Purpose: To compare diffusion, metabolic and vascular characteristics in histologically-defined prostate tumour with non-tumour and determine which parameters detect tumour most accurately. Methods and Materials: Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-W, diffusion-weighted, 2-D chemical shift and dynamic contrast-enhanced images were acquired. At prostatectomy, transversely sectioned fresh slices and stained whole-mounts with histologically-defined tumour outlines were photographed. These tumour regions (TU) were mapped to the corresponding T2-W image and apparent diffusion coefficients (ADC), choline/citrate ratios (Cho/Cit) and vascularity obtained for TU, normal peripheral zone (PZ) and central gland (CG). ROC curves determined the combination of parameters with highest sensitivity and specificity for prostate cancer detection. Results: In TU= 1 cm2, ADC and Cho/Cit were significantly different compared with non-TU PZ+CG (p=0.003), PZ alone (p 0.001) and CG alone (p=0.046). TU vascularity was increased in TU compared with PZ+CG (initial area under the gadolinium curve (IAUGC):p=0.012, forward rate constant (Ktrans):p=0.011, return rate constant (Kep):p=0.036 and PZ alone (IAUGC:p=0.007, Ktrans:p 0.001, Kep:p=0.011) but not CG. Combined ADC and IAUGC were significantly better than either parameter alone (p = 0.001), combined ADC and Cho/Cit was significantly better than ADC (p=0.001) but not Cho/Cit (p=0.175) and combined Cho/Cit and IAUGC was significantly better than IAUGC (p 0.001) but not Cho/Cit alone (p=0.338). All three parameters together did not improve sensitivity and specificity further. Conclusion: Combination of any two functional parameters provides highest sensitivity and specificity for prostate cancer detection and is significantly better than any technique alone. Using a third parameter does not improve this further. based diffusion weighted-imaging (DWI) protocol (b-values:50,400,800) including a calculated apparent diffusion coefficient map (ADC), a 3D-T2w SPACE protocol, a 3D-CSI spectroscopy protocol and a dynamic contrast enhanced imaging (DCE) protocol based on a 3D-GRE-sequence (VIBE). The diagnosis was confirmed by TRUS-guided biopsy in 20 patients and MRI-guided biopsy in 4 cases by performing 8 biopsy cores in each patient. The examination time was 75 minutes. Results: Cancer was found in 13 cases at histology, 11 patients showed benign conditions as benign prostate hyperplasia (BPH) and chronic prostatitis. For cancer detection the combination of T2w-, diffusion-, spectroscopic- and T2-mappingimaging yielded the highest sensitivity. A lower sensitivity, but a higher specificity in cancer depiction could be evaluated by adding T2/T2*-mapping, spectroscopicand DCE-imaging to T2w-imaging protocols. When all six imaging modalities were applied, a sensitivity of 86% and a specificity of 90% in tumor detection could be achieved. Conclusion: The demonstrated MR protocol integrating six different MR methodologies can improve prostate cancer detection and raise the probability of further tumor negative biopsy results but is time consuming. The method can be a valuable instrument for selecting candidates either for a repeated prostate biopsy or PSA controlled watchful waiting. Scientific Sessions biopsy alone in 83 (15%). The detection rate for targeted biopsy cores (10.8% or 961 of 8,880 cores) was significantly better than for systematic biopsy cores (4.5% or 923 of 20,080 cores, P 0.001). Conclusion: These largest data in literature show that contrast-enhanced colour Doppler-targeted prostate biopsy is superior to systematic prostate biopsy in a screening population. 10:30 - 12:00 B-489 Moderators: W. Buchberger; Innsbruck/AT M. Mellado; Pamplona/ES 11:42 Prospective randomised control trial: Impact of combined un-enhanced and dynamic contrast-enhanced MRI prior to TRUS biopsy in patients being investigated for a raised PSA J.T. Smith, B. Crabtree, S. Bacon, D. Wilson, P. Harnden, B. Carey; Leeds/UK ([email protected]) Purpose: Straight to biopsy is currently the gold standard in investigating patients with a raised PSA. As PSA is not specifically raised in patients with prostate cancer, the majority of biopsies do not identify adenocarcinoma. We set out to investigate whether CEMRI in addition to T2W imaging prior to biopsy increased the cancer diagnostic yield. Methods and Materials: Local ethics approval was obtained. 40 consecutive unselected patients referred for biopsy were randomised to either straight to biopsy (control arm) or CEMRI + T2W prostate imaging prior to biopsy (interventional arm). Results: Both control and interventional arms were equally represented with 20 patients. Mean age, PSA and size of gland were 65 years, 11 ng/L and 57 cc in the control arm and 67 years, 11 ng/L and 66 cc in the interventional arm. 6 patients in the control arm and 5 patients in the interventional arm were found to have cancer. In the control arm: 162/171 (95%) were untargeted biopsies and 9/171 (5%) targeted biopsies. 16/162 (10%) of the untargeted biopsies were positive for cancer and 3/9 (33%) targeted biopsies were positive for cancer. In the interventional arm: 144/170 (85%) were untargeted biopsies and 26/170 (15%) were targeted biopsies. 15/144 (10%) of the untargeted biopsies were positive for cancer and 6/26 (23%) targeted biopsies were positive for cancer. Conclusion: There is no value in using CEMRI plus T2W imaging prior to prostate biopsy in unselected patients being investigated for a raised PSA. B-490 11:51 Dynamic-contrast-enhanced MRI and MR-guided biopsy in the detection of local recurrence after radiation therapy for prostate cancer D. Yakar, T. Hambrock, J.J. FГјtterer, H. Huisman, E. van Lin, J.O. Barentsz; Nijmegen/NL ([email protected]) Purpose: To assess the potential value of 3 T MR-guided biopsy of tumor suspicious regions (TSR) on 3 T dynamic-contrast-enhanced (DCE) MRI to detect prostate cancer recurrence following radiotherapy. Methods and Materials: In this pilot study, 17 patients with prostate cancer previously treated with radiotherapy ( 1 year before) underwent an endorectal coil 3 T MRI (Siemens, Trio Tim, Germany) following three consecutive rises in PSA. Two radiologists in consensus determined the TSR from DCE-MR images. An MR biopsy device (Invivo, Germany) was used in conjunction with a phased array coil to perform prostate biopsies under 3 T MR guidance. Anatomical landmarks and features on T2-weighted turbo spin echo and TRUE-FISP images were used to translate prior-determined TSR for biopsy. A total of 14 patients received MR-guided biopsies, while 3, due to evidence of metastatic disease, did not. Results: The average duration of MR-guided biopsies was 30 min. In total, 50 biopsy cores of 27 different TSR were obtained. The median number of cores taken per patient was 3 (range 2-5). Prostate cancer was found in 12/14 (86%) patients and 20/27 (positive predictive value of 74%) were positive for tumor on biopsy. One TSR contained normal tissue, one TSR contained residual tumor with radiotherapy effects, while 5/27 of the remaining TSR contained radiotherapy-induced reactive atypia. No procedure-related complications occured. Conclusion: This pilot study shows that 3 T MR-guided biopsy of TSR on 3 T DCE-MRI has a potential value in improving the detection of local prostate cancer recurrence following radiotherapy. S252 A B C D E F G F H Room F2 Breast SS 1002 US and follow-up after surgery B-491 10:30 The role of second-look ultrasound in evaluating suspicious breast MRI lesions A. Russo, G. Carbognin, C. Calciolari, V. Girardi, R. Pozzi Mucelli; Verona/IT ([email protected]) Purpose: To estimate the value of second-look US detection of suspicious lesions diagnosed by contrast-enhanced breast MRI. Methods and Materials: We reviewed the final reports of 498 MRI. Recommendations for second look were given in 50 patients (10%), who underwent MRI for preoperative staging of known cancer (36), scar tissue evaluation (7), studying equivocal mammographic-ultrasound findings (3), monitoring response to neoadjuvant chemiotherapy (1), screening in women with familial cancer (1) and studying breast implants (2). We tabulated the results of subsequent US, pathologic diagnoses from surgery and from biopsies performed after second look. Results: Of 50, 36 (72%) additional MRI lesions were identified by second look. Biopsies were carried out in 25/36 patients with US findings: 10 were shown to be positive for malignant lesion (27% of sonographic findings). Of 50, 14 (28%) were not identified by second look. Surgery was carried out for 4/14 with no US findings and MR guided-biopsy in 1/14:4 was shown to be positive for additional malignant lesion (28% of sonographic occult findings), (two of category 4 and two of category 5 according to MRI BI-RADS). Conclusion: There are no differences in the rates of malignancy for suspicious MRI lesions, US detected (27.7%) and US occult (28.5%) at second look. Given the benefits of US-guided biopsy, second-look US is a reasonable initial approach, but the lack of US detection does not negate the need for biopsy of suspicious MRI lesions, especially considering our study population and MRI BI-RADS categories. B-492 10:39 The challenge of imaging dense breast parenchyma: Is MR mammography the technique of choice? A comparative study with X-ray mammography and ultrasound S. Cagioli, F. Pediconi, A. Roselli, V. Dominelli, M.L. Luciani, V. Casali, C. Catalano, R. Passariello; Rome/IT ([email protected]) Purpose: To establish the value of magnetic resonance imaging (MRI) of the breast relative to X-ray mammography and ultrasound for breast cancer evaluation in women with dense breast parenchyma. Methods and Materials: A total of 238 women with dense breast parenchyma (BI-RADS 3 or 4) who were suspicious for breast cancer or inconclusive for the presence of breast lesions based on clinical examination, ultrasound or X-ray mammography and who underwent breast MRI at 1.5 T before and after administration of 0.1 mmol/kg gadobenate dimeglumine were evaluated. Lesions considered malignant on breast MRI (BI-RADS 4 or 5) were evaluated histologically; the final diagnosis of other patients was based on a 12-18-month follow-up. The diagnostic performance (sensitivity, specificity, accuracy and positive and negative predictive values) of each technique was determined and compared (chi-square test). Results: At final diagnosis, 121/238 (50.8%) women had confirmed malignant lesions, whereas 117 (49.2%) had benign or no lesions. Significantly (P 0.015) better diagnostic performance was achieved with breast MRI (diagnostic accuracy 95.4 vs. 57.2% for X-ray mammography and 72.3% for ultrasound). Among 97 women who underwent all three techniques, more lesions were detected with breast MRI (n = 135) than with X-ray mammography (n = 85) and ultrasound (n = 107) and the diagnostic confidence was greater. Breast MRI detected more cases of multifocal, multicentric and contralateral disease and fewer misdiagnoses occurred. Conclusion: Breast MRI is more effective than X-ray mammography and ultrasound for the detection of breast cancer in women with dense breast parenchyma. Scientific Sessions B-493 10:48 The value of second look ultrasound as a confirmatory method for incidental enhancing lesions found on breast MRI F. Pediconi, A. Roselli, V. Dominelli, S. Cagioli, M.L. Luciani, V. Martino, C. Catalano, R. Passariello; Rome/IT Purpose: To evaluate the role of second look high-resolution ultrasound for the identification of incidental enhancing lesions detected on preoperative breast MRI that have no X-ray mammographic or palpable correlate. Methods and Materials: Between January 2004 and March 2006, 182 patients with confirmed breast cancer based on conventional X-ray mammography or US underwent breast MRI with 0.1 mmol/kg gadobenate dimeglumine for breast cancer staging. Patients with incidental lesions on breast MRI underwent a second look high-resolution US examination directed at the site of the incidental finding. Comparison between the two imaging modalities was performed. Results: Breast MRI detected 55 additional enhancing lesions in 46/182 patients that were not seen on X-ray mammography or first look US. Of these 55 additional lesions, 43 corresponding lesions were detected on second look US. US-guided biopsy or US-guided wire localisation followed by excisional biopsy subsequently confirmed that 19 of these 43 lesions were malignant. Treatment planning was altered for four patients with multicentric cancer and seven patients with multifocal cancer based on combined breast MRI and US findings. The 12 lesions detected on CE-MRM for which a corresponding lesion was not detected on second look US were evaluated on MR-guided biopsy or re-assessed by CE-MRM after 3 months. One of these 12 lesions was confirmed as malignant. Conclusion: Direct second look US is a confirmatory method for incidental findings in breast MRI. The likelihood of carcinoma is higher for lesions with a US correlate than for lesions without a US correlate. B-494 10:57 Purpose: To determine the performance of an additional ultrasound examination to mammography in case of breast density ACR 3 and 4 in symptomatic or women at risk. All patients were examined in the project “quality assurance in breast cancer diagnosis” (the QuaMaDi Project). In Schleswig-Holstein/Germany this processorientated and comprehensive quality management project was implemented to improve the standard of breast cancer diagnosis. Methods and Materials: A prospective cohort between 2001 and 2005 with a total of 59,514 patients and 102,744 mammograms was initiated. Breast ultrasound was indicated in all women with ACR III and IV, in addition to a suspicious clinical examination and in cases of masses in mammography. Abnormalities were defined positive if biopsy findings revealed malignancy, and negative if biopsy findings or all examinations turned out to be benign. Results: Overall 116 mammographically occult breast cancers were diagnosed by ultrasound out of 62,006 cases (1.9/1000 examinations). Additionally, 12.8% breast cancers were detected by mammography + US (1019 cancers) vs mammography alone (903 cancers). In group ACR III/IV supplementary 15.9% cancers were found by additional US than mammography alone. Conclusion: Supplementary US to mammography vs mammography alone resulted in a significant breast cancer detection rate increase of 15.9% in case of ACR 3 and 4. B-495 11:06 Real-time virtual sonography improves localization of suspicious lesions on breast MRI at second-look sonography S. Nakano, K. Fujii, K. Yorozuya, M. Yoshida, T. Fukutomi, T. Ishiguchi; Aichi-gun/JP ([email protected]) Purpose: To assess the value of real-time virtual sonography (RVS) for localization of suspicious lesions on breast MRI. Methods and Materials: A total of 92 patients underwent breast MR, 55 patients for staging of known breast cancer, and 37 patients for including abnormal findings on conventional images. All the patients were examined using MMG, US, and RVS enabling both US and MRI cutaway images of the same site, displaying these images in real time. Breast MR images were obtained on a 1.5-T imager in the supine position using a flexible body surface coil. Results: A total of 119 lesions were evaluated with RVS at diagnosis and before surgery. The overall sensitivity for detecting primary breast tumors was 74% B-496 11:15 Can microvascular imaging of breast lesions using microbubbles accurately distinguish benign from malignant lesions? P.G. Sorelli, D.O. Cosgrove, W. Svensson, N. Zaman, K. Satchithananda, N.K. Barrett, A.K. Lim; London/UK ([email protected]) Purpose: Fundamental and Doppler imaging of solid breast masses cannot accurately distinguish malignant from benign lesions. We investigate whether microvascular enhancement with ultrasound imaging can aid in distinguishing between benign and malignant lesions and correlate these findings with histology. Methods and Materials: 15 patients were recruited from Rapid Diagnostic clinics with palpable breast lumps. Following informed consent, 5 mls of the microbubble SonoVue were injected intravenously. Digital clips of the enhancement of the lesion were obtained using a high frequency, low mechanical index specialised bubble mode using a 7.5 MHz probe. Clips were reviewed by an experienced Consultant radiologist who scored each lesion on the following characteristics: benign vs malignant, homogeneous vs heterogeneous enhancement, the presence or absence of focal defects, well vs ill-defined structure and vascular morphology score (VMS). Statistical analysis was carried out using the Mann Whitney U and Chisquare tests. Results: 15 solitary lesions were examined. 7 were malignant and 8 benign histologically. 8 patients underwent surgery, 3 core biopsy and 4 fine needle aspiration (FNA). The calculated sensitivity for the procedure was 100%, with 37.5% specificity. The overall mean VMS and mean VMS for localisation, vessel pattern and density were higher in the malignant lesions compared to the benign lesions. Conclusion: The results of our study have not shown any additional benefit in the use of contrast enhanced ultrasound over conventional triple assessment. The positive trend seen in the higher mean VMS for the malignant tumours needs further investigation with a larger cohort of patients. B-497 11:24 Ultrasound of the surgical specimen in early stage breast cancers: Accuracy in the evaluation of resection margins V. Londero, A. Linda, C. Zuiani, M. Panozzo, R. Fazzin, M. Bazzocchi; Udine/IT ([email protected]) Purpose: To evaluate the accuracy of the US surgical specimen in the assessment of the status of resection margins after breast-conserving surgery. Methods and Materials: Sonographic examination of 29 surgical specimens of US-detectable malignant tumors was performed. Distance of the lesion from the specimen margins in radial directions was measured and compared with the distances measured on pathologic examination. Positive pathologic margins were defined when invasive or intraductal carcinoma was found within 2 mm of the specimen margin. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of US were calculated considering a 10-mm and 4-mm cut-off for the assessment of margins’ status. Results: The median sonographic size of neoplasms was 12 mm (6-35 mm). Of 116 margins (4 per lesion), pathology demonstrated 18 positive and 98 negative margins. Considering the 10-mm cut-off, US identified 17 positive and 99 negative margins, showing sensitivity, specificity, PPV and NPV of 22.2%, 86.7%, 23.5% and 85.8%, respectively. Considering the 4-mm cut-off, US identified 3 positive and 113 negative margins with a sensitivity of 11.1%, specificity of 98.9%, PPV of 66.7% and NPV of 85.8%. False-negative results were more frequent in case of invasive lobular carcinoma (21.4%) and presence of intraductal component (42.8%). Conclusion: Sonography demonstrated a poor performance in the evaluation of the status of surgical margins; however, due to its high NPV, both with 10-mm and 4-mm cut-off, it might be helpful in confirming complete excision of a US-detected neoplasm and in ruling out the presence of invasive ductal carcinoma at surgical margins. A B C D E F G H S253 Sunday Additional ultrasound to mammography in case of breast density ACR III/IV: Is there a higher detection rate of breast cancer in an analysis of 102,744 diagnostic processes? F.K.W. Schaefer, A. Katalinic, P.J. SchГ¤fer, B.M. Order, C. Wefelnberg, W. Jonat, I. Schreer; Kiel/DE ([email protected]) (43/58) for MMG, 93% (54/58) for US, 97% (56/58) for MRI, and 97% (56/58) for RVS, respectively. A virtual MPR image of the target tumor was displayed under good condition correspondence with the US image in all patients. MRI-detected suspicious lesions (BI-RADS 4) were found in 61 lesions which were not expected from the previous conventional techniques. Of these, 48% (29/61) of suspicious lesions (SL) could be identified only on repeated US, but 90% (55/61) of SL could be identified easily using the RVS system (P 0.05). Histologically, 9.8% (6/61) of SL were invasive carcinoma. Conclusion: The present results suggest that RVS appears to be not time consuming technique which can identify a large part of incidental MRI findings, and can accurately select the cases in which MRI-guide biopsy are required. Scientific Sessions B-498 11:33 Evaluation of mammographic diagnosis of breast cancer recurrence in transversus abdominis muscle flap reconstructions L. Johnston, M. Buckley, S. Refsum; Belfast/UK ([email protected]) Purpose: Breast cancer recurrence in transversus abdominis muscle (TRAM) flap reconstructions is low and diagnosis on mammogram alone is very low. The study was undertaken to evaluate this premise based on the experience in our institution. Methods and Materials: All patients who had TRAM flap breast reconstruction from January 1999 to March 2008 were identified from the Breast Service database. Any recorded recurrences were validated using the Clinical Oncology Information System (COIS). Results: A total of 59 patients had TRAM flap reconstructions. One patient was excluded from the study as she had an additional silicone implant. Only one patient was found to have local recurrence and this was diagnosed clinically. No patient was diagnosed with recurrence on mammogram alone. Five patients were deceased and all were diagnosed with metastases not related to TRAM flap recurrences. The remainder of the patients were undergoing annual clinical and mammographic surveillance. Conclusion: This study supported the premise that breast cancer recurrence in TRAM flap reconstruction is low and that the mammographic detection rate of nonpalpable recurrence alone is very low, being zero in our study. Therefore, the usefulness of post TRAM flap reconstructions mammogram surveillance in the evaluation of these patients requires further evaluation. B-499 11:42 Computerized analysis of breast lesions using mammography and breast ultrasonography M. Lyra, C. Skouroliakou, S. Lyra, C. Georgosopoulos; Athens/GR ([email protected]) Purpose: The aim of this study is to extract texture descriptors of breast lesions from mammographic and ultrasonic breast images, in order to evaluate the combined use of these two imaging modalities in the computerized classification of breast lesions. Methods and Materials: A total of 65 lesions (20 cysts, 30 benign solid masses and 15 malignant solid masses) were manually segmented from the mammograms and the ultrasonic images. Four Haralick’s descriptors (homogeneity, contrast, energy and correlation) were calculated as texture features of the segmented lesions. Stepwise logistic regression and binary logistic regression were applied in order to automatically classify breast lesions for different data combinations: a. taking into account only the ultrasonic images, b. considering only the mammograms and c. using data from both modalities. Results: Classification success rate was higher (95%) when texture descriptors extracted from both imaging modalities were used to construct the classification model. A success rate of 89% was achieved when the ultrasonic images were used, while the classification model based on the mammographic images reached an 80% of successfully classified lesions. Conclusion: Computerized analysis of ultrasonic and mammographic images has the potential to contribute to the diagnostic accuracy of distinguishing between benign and malignant lesions of the breast, through the implementation of CAD systems. B-500 11:51 Breast imaging in patients after bilateral breast augmentation with new injectable filler materials A. Artmann, N.A. BГ¶hm, M. Geishauser, E. Rummeny; Munich/DE ([email protected]) Purpose: Breast augmentation with hyaluronic acid gel (HAG), a new filler material, is becoming a more frequently performed cosmetic surgery method. So far, no data exist regarding the diagnostic accuracy of different breast imaging methods in women after HAG augmentation. The aim of this study was to report first experiences with multi-modality diagnostic breast imaging in symptomatic patients with HAG. Methods and Materials: Five women (age range, 35-48 years) underwent HAG injection. The patients were referred to our breast imaging service, 3 months to 2 years post treatment, because of pain, unknown nodularity and newly palpated lumps. Mammography, ultrasound and 3D-(Gd)-enhanced (1.5 T) T1-w FLASH MR mammography with a dedicated breast coil were performed. Results: One patient was diagnosed with multicentric breast cancer (BC), two had fibroadenomas and two had gel migration. In mammography, the radiographically dense HAG impaired the depiction of BC and fibroadenomas. Ultrasound failed to identify all breast cancers, but detected two fibroadenomas. However, because S254 A B C D E F G F H of the irregularly distributed HAG, assessing lesion features with ultrasound was difficult, especially for the differentiation between benign and malignant masses. MRI detected and correctly classified BC and fibroadenomas. Fast spin echo T2weighted images were the best for gel localization and displacement. In combination with dynamic contrast-enhanced T1-w images and subtraction images, suspicious enhancing masses were differentiated from HLA pockets. Conclusion: Breast MRI seems to be the most effective imaging tool after breast augmentation with HAG, because it allows to differentiate accurately between gel pockets and breast masses and helps to detect gel migration. 10:30 - 12:00 Room G/H Abdominal Viscera (Solid Organs) SS 1001b Liver and biliary system: MRI Moderators: B.J. Op de Beeck; Antwerp/BE C.S. Reiner; Zurich/CH B-501 10:30 Evaluation of liver iron concentration (LIC) in patients with thalassemia and sickle cell disease at 3 T in comparison to 1.5 T F.P. Junqueira1, G.M. Cunha1, A. Coutinho1, T.M. Doring1, A.A. Carneiro2, J.L. Fernandes3, R.C. Domingues1; 1Rio de Janeiro/BR, 2RibeirГЈo Preto/BR, 3 Campinas/BR ([email protected]) Purpose: To determine the liver iron concentration (LIC) using relaxometry (T2*) at 3 T and to compare to 1.5 T. Methods and Materials: The measurement of the relaxation time T2* (known as relaxometry) from MRI images can be used for evaluation of the iron concentration in the liver. MRI images of 12 patients were obtained at two different MR field strengths, 1.5 T and 3 T, using a GRE sequence applying 15 different echoes. T2* measurements were performed at both field strengths and compared by combining the data through linear regression. The LIC at 1.5 T was calculated using the calibration equation established by a phantom at 1.5 T and a correction factor (the slope of the previously linear combined T2*) was applied to the T2* values at 3 T to measure the LIC at 3 T. The results were tested for linear relationship. Results: The combined T2* data of all subjects at 1.5 and 3 T showed high linear relationship (R = 0.98, P 0.001). The curve of the linear fit had a slope of 1.41 p 0.08. The calculated LIC covered a range from 1.5 to 21 mg/g and the slope of the combined data at different field strengths was 0.88 p 0.11 (R = 0.98, P 0.001). Conclusion: The calculated LIC at 3 T shows a high linear relationship to the 1.5 T measurement. A correction factor has to be applied at 3 T when compared to a calibrated 1.5 T scanner. Keywords: MRI, T2*, liver iron concentration (LIC), thalassemia B-502 10:39 Magnetic resonance imaging and magnetic resonance angiography of the liver and hepatic vasculature in patients with hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber-disease) A. Massmann1, P. Fries1, M. Wirth1, U.W. Geisthoff2, A. Buecker1, G.K. Schneider1; 1 Homburg a.d. Saar/DE, 2Cologne/DE Purpose: To evaluate liver involvement in patients with hereditary hemorrhagic telangiectasia (HHT). Methods and Materials: 230 patients (mean age: 46.9; male 9; female 134) with HHT, or first-degree relatives, underwent non-contrast and contrast-enhanced (Gd-BOPTA 0.05 mmol/kg bodyweight) MRI of the liver for detection of hepatic manifestations of HHT. Results: MRI revealed 38/230 patients (mean age: 57; male 8; female 30) with hepatic and vascular pathologies related to HHT. Hepatomegalia and hepatic arterio-venous malformations (HAVM) were found in 28/38 and 21/38 patients, respectively. Right-heart-insufficiency (RHI), due to HAVM, was present in 9 patients, who did not suffer from hemodynamically relevant pulmonary AVM (PAVM). An enlarged diameter of the hepatic artery (HA) correlated with increased nodular hyperplastic changes of the liver (19 patients), a lower RHI-rate, and inversely with the diameter of the portal vein. Conclusion: HHT-patients with a hepatomegaly and nodular hyperplastic changes of the liver most likely have shunts at the sinusoidal level. Direct arterio-venous and arterio-portal shunts are associated with an almost normal liver size without hyperplastic changes. The increased arterial blood supply to the liver could explain the Scientific Sessions nodular hyperplastic changes similar to the mechanism of focal overgrowth of liver tissue discussed in the development of FNH. HAVM causing hyperplastic nodules do not result in direct hemodynamical left-to-right-shunts, while HAVM without hyperplastic nodules is likely to cause RHI, even in the absence of PAVM. Consequently, RHI might not be treated sufficiently by embolization of PAVM alone. B-503 10:48 Accurate differentiation between small or atypical hemangiomas and cystic or hypervascular metastases using ferucarbutran-enhanced MRI A. Ba-Ssalamah, S. Machat, N. Bastati, S. Baroud, C. Kulinna, C.J. Herold, W. Schima; Vienna/AT ([email protected]) B-504 10:57 Diffusion-weighted MRI for assessment of hepatic metastases: Comparison with superparamagnetic iron oxide (SPIO)-enhanced imaging H. Kim, J. Yu, D. Kim; Seoul/KR ([email protected]) Purpose: The aim of this study was to validate diffusion-weighted imaging (DWI) as a substitute for superparamagnetic iron oxide (SPIO)-enhanced MRI for assessment of hepatic metastases. Methods and Materials: A total of 86 hepatic metastases in 22 patients were subjected to a retrospective analysis for detection rate on the DWI and SPIO-enhanced MRI. DWI using spin-echo planar sequence (b factors of 50, 400 and 800 sec/mm2) was performed before and after SPIO injection, and SPIO-enhanced T2*-weighted images (SPIO-T2*) were compared with pre- and post-SPIO DWI (SPIO-DWI) by two independent radiologists. Individual lesions were subjectively scored for the conspicuity of the lesion using a five-grade scale (0-4). All lesions were divided into two groups (group 1, 1 cm; group 2, r1 cm in the longest dimension). Results: Regardless of the size of the lesions, all the conspicuity scores of DWI were lower than that of SPIO-T2* (P 0.05), except for SPIO-DWI with b factor of 50 sec/mm2 (P = 0.732). For lesions smaller than 1 cm, DWI with b factor of 50 sec/mm2, and SPIO-DWI with b factor of 50 sec/mm2 and 400 sec/mm2 showed no significant difference in lesion conspicuity to SPIO-T2* (P = 0.06, 0.68, 0.35). Even in DWIs, SPIO-DWI showed significantly higher conspicuity scores than precontrast DWI regardless of the size of b factors in all lesions (P 0.05). Conclusion: Despite the comparable value for the subcentimeter hepatic metastases between the DWI using small b factors and SPIO-T2*, precontrast DWI cannot substitute for SPIO-enhanced imaging for assessment of overall hepatic metastases. 11:06 Colorectal liver metastases: Detection with SPIO-enhanced MR imaging in comparison with gadobenate dimeglumine-enhanced MR imaging and CT imaging K. Hekimoglu1, Y. Ustundag2, H. Engin2, O. Erdem2; 1Ankara/TR, 2Zonguldak/TR ([email protected]) Purpose: The aim of this prospective study was to compare the diagnostic role of superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging (MRI) versus gadobenate dimeglumine (Gd)-enhanced MRI and computed tomography (CT) investigations for the detection of liver metastases of colorectal cancer. Methods and Materials: A total of 30 patients with liver metastases enrolled in this study and 78 colorectal metastatic liver lesions were evaluated with dynamic CT imaging, Gd-enhanced MRI and SPIO-enhanced MRI. Agreement between the readers and three algorithms were analysed by Kappa statistics. Differences between the lesion detection ratios of the methods were analysed by two proportion z test. Sensitivity values were also calculated. Results: Interobserver agreement between two reviewers (R1, R2) with kappa analysis was found to be the best for the three modalities. Kappa values were 0.866, 0.843 and 1.0, respectively. For all the 78 liver colorectal metastases, SPIOenhanced MRI detected all lesions with two reviewers (100% sensitivity). This sensitivity value was higher than Gd-enhanced MRI, and there was a significant difference (P 0.05). Gd-enhanced MRI depicted 71 lesions and this modality could not detect 7 lesions with two reviewers (91% sensitivity). This modality had moderate sensitivity, and this value was greater than in CT imaging, so there was a significant difference also (P 0.05). Dynamic triphasic CT imaging detected 64 (R1) and 65 (R2) lesions. This modality had the lowest sensitivity (R1:0.82, R2:0.83 respectively). Conclusion: Colorectal liver metastases were best detected with SPIO-enhanced MR imaging against Gd-enhanced MR imaging and CT imaging. For diagnosing suspected colorectal liver metastases, this could be the primary alternative modality. B-506 11:15 The 3.0 T MRI of the liver with a volumetric interpolated breath-hold technique in comparison to MDCT: Preliminary results W.K. Matzek, N. Bastati-Huber, S. Baroud, C. Kulinna, C.J. Herold, W. Schima, A. Ba-Ssalamah; Vienna/AT ([email protected]) Purpose: To compare gadolinium-enhanced T1w 3D, GRE breath-hold sequence (volumetric interpolated breath-hold examination or VIBE) for 3.0 T MRI with contrast-enhanced MDCT in the detection and characterization of focal liver lesions (FLL) by using consensus evaluation and other findings as the reference standard. Methods and Materials: A total of 43 patients (22 men, 21 women; mean age 58 y) with 114 FLLs were examined in either 16- or 64-row MDCT (Sensation, Siemens) and 3.0 T MRI (Trio, Siemens). Two observers reviewed the dynamic contrast-enhanced MDCT and dynamic gadolinium-enhanced VIBE for FLL detection and characterization. The reference standard for diagnosis was obtained from consensus review by the observers of both modalities, pathologic data and follow-up imaging. The results of the contrast-enhanced MDCT and gadoliniumenhanced VIBE were compared. Results: From a total of 114 FLLs (78 malignant, 34 benign), only 100 lesions were detected by MRI (88%) at a consensus review. Only 92 lesions were detected by MDCT (81%), and the difference between both modalities was not statistically significant. Gadolinium-enhanced VIBE achieved an accuracy of 90 versus 78% for MDCT in FLL characterization. Conclusion: Gadolinium-enhanced T1wVIBE at 3.0 T is equal to MDCT in FLL detection, however superior in characterization of focal liver lesions. B-507 11:24 Accuracy of retrospective multimodality image fusion between 18 F-FDGPET and MRI in patients with malignancies of the upper abdomen O.F. Donati, C.S. Reiner, T.F. Hany, B. Marincek, D. Weishaupt; Zurich/CH ([email protected]) Purpose: To evaluate the accuracy of retrospective rigid image fusion between 18 F-FDG PET and MRI of the upper abdomen. Methods and Materials: Image fusion of PET and MRI was performed in 30 patients with suspected malignancy of the liver or pancreas. Using a commercially available image fusion tool capable of rigid manual point-based registration, PET-Images were retrospectively fused by matching eight homologous points in MRI studies and in the CT-part of PET/CT. Two separate readers (R1, R2) assessed accuracy of image registration by determining the distances in the x-, y- and z-direction as A B C D E F G H S255 Sunday Purpose: To evaluate the efficacy of ferucarbotran-enhanced MRI in the differentiation of cystic or hypervascular metastases from small or atypical hemangiomas of the liver using either the histopathologic results or long-term follow-up as standard of reference. Methods and Materials: A total of 112 focal hepatic lesions in 32 patients (20 m, 12 f, mean age 67.8 years) with clinical history of malignant disease and previous equivocal CT or US examinations were evaluated using unenhanced and ferucarbotran-enhanced MRI. The SI pattern of each kind of lesion was assessed and categorized into 3 categories: high SI on unenhanced T2-w TSE FS images with significant SI loss on ferucarbutran-enhanced T2-w TSE FS images and increase of SI on ferucarbutran-enhanced delayed 3D T1-w GRE images (category A), high SI or moderate to low SI on unenhanced T2-w TSE FS images, respectively, without SI change on both ferucarbutran-enhanced T2-w TSE FS and delayed-3D T1-w GRE images (categories B and C). Results: Lesions were categorized as follows according to the final diagnosis: 48 hemangiomas (category A), 12 cysts (category B), and 52 metastases (category C). The only lesions showing a significant increase in SI on postcontrast T1-w 3DGRE images were hemangiomas on average by 60% (p 0.001). The only lesions showing a significant decrease in SI on postcontrast T2-w TSE FS images were hemangiomas on average by 40% (p 0.001). Conclusion: The combined signal intensity pattern on ferucarbutran-enhanced T2-w and T1-w helps to accurately differentiate small or atypical hemangiomas from cystic or hypervascular metastases. B-505 Scientific Sessions well as the 3-dimensional distance between 4 and 6 anatomical landmarks. Quality of fusion was graded using a three-point grading scale (1, poorly fused; 2, satisfactory fused; 3, correctly fused). Results: Mean time of registration per patient was 2.04 min. Objective registration assessment showed errors between 3.18-6.31 mm in x-axis [mean 4.16 mm (R1); 4.26 mm (R2)], 3.6-9.27 mm in y-axis (mean 6.18 mm; 5.8 mm) and 3.69-11.51 mm in z-axis (mean 5.16 mm; 5.59 mm). The error in 3-dimensional distances between points was 7.25-16.76 mm (mean 9.68 mm; 10.54 mm). In visual assessment, most fusions were graded to be satisfactory or correctly fused [R1, R2: grade 3, 11/30 (36.7%), 22/30 (73.3%); grade2, 13/30 (43.3%), 8/30 (26.7%); grade1, 6/30 (20%), 0/30 (0%)]. Fusions were mostly comparable to hybrid PET/CT fusions. All of the registrations were defined as “diagnostic” by both readers. Conclusion: Retrospective rigid image fusion of PET and MRI of the upper abdomen is feasible without adaptation in image acquisition protocols and shows sub-centimeter registration errors. B-508 11:33 Accuracy of preoperative T- and N-staging of gallbladder carcinoma using gadolinium-enhanced dynamic MRI S. Kim, J. Lee, J. Lee, S. Kim, J. Han, B. Choi; Seoul/KR ([email protected]) Purpose: To evaluate the performance of dynamic gadolinium-enhanced (Gd-E) MRI in the T- & N- staging of gallbladder cancer (GBC). Methods and Materials: 60 patients with surgically resected and pathologically confirmed as GBCs were enrolled in this study. All patients were examined preoperative, Gd-E dynamic MRI. The T2 HASTE, T1 weighted in-/opposed phase and Gd-E dynamic MRI were independently evaluated by two observers. They graded their diagnostic confidence for: 1) loss of low SI on T2WI for differentiating rT1b from bT1a lesions 2) disruption of outer ring of the GB wall on T1WI for diagnosing rT3 lesions, and 3) delayed subserosal enhancement for rT2 lesions using a 5-point scale and evaluated final T-&N-stage of the GBCs. ROC analysis was performed for evaluating diagnostic value of each findings. Interobserver agreement was evaluated with kappa statistics. The sensitivity, specificity and overall accuracy of T- & N- staging were evaluated. Results: Az values for diagnosing 1) rT1b GBC on T2WI were 0.904 and 0.910, 2) rT3 GBC on T1WI were 0.907 and 0.819, and 3) rT2 GBC on delayed phase were 0.915 and 0.862, respectively. The interobserver agreement was good (k=0.793). The overall accuracy of T-&N-staging were 80 and 76.7% in observer 1, and 66.7 and 73.3% in observer 2, respectively. Az value of diagnostic ability to differentiate rT1b from bT1a lesions were 0.874 and 0.840 in each observer (p = 0.0001). Conclusion: The diagnostic ability to differentiate rT1b from bT1a lesions using Gd-E dynamic MRI was acceptable and this result can help for preoperative surgical planning. B-509 11:42 Diagnostic value of magnetic resonance cholangiography in the identification of biliary tract strictures after liver transplantation S. Kinner, A. Dechene, S.C. Ladd, P. Hunold, G. Gerken, T. Zoepf, J. Barkhausen, T.C. Lauenstein; Essen/DE Purpose: Post liver transplantation biliary obstruction is frequently caused by strictures of the anastomoses or the intra- and extrahepatic bile ducts. Our study aimed to assess the diagnostic accuracy of magnetic resonance cholangiography (MRC) for the detection and characterization of post liver transplant biliary strictures (PTBS) using endoscopic retrograde cholangiography (ERC) as the standard of reference. Methods and Materials: A total of 59 liver transplant patients (median age 49 years; 28 female, 31 male) with biliary obstruction were included in this blinded prospective study. MRC was performed on 1.5 T scanner using 2D single shot RARE as well as high-resolution navigator-corrected 3D MRC sequences in all patients within 48 h prior to ERC. MRC and ERC were interpreted independently by two trained radiologists and two gastroenterologists, respectively. The presence of strictures and their localisation were assessed. Results: ERC showed relevant PTBS in 47/59 patients, while MRC identified stenoses in 48/59; 23/47 patients presented anastomotic strictures (AST), 18/47 patients ischemic type biliary lesions (ITBL) and 6/47 patients a combination of both kinds of lesions in endoscopic retrograde cholangiography. As compared to 16/18 cases of ITBL, 19/23 cases of AST were identified correctly by MRC. MRC overestimated/ misjudged stenosis more often in ITBL than in AST. Conclusion: MRC is able to detect biliary stenoses in general with a slight tendency to overestimation. However, in the presence of central stenoses, MRC is able to assess the peripheral ducts even more precisely than ERCP. S256 A B C D E F G F H B-510 11:51 MRI of biliary tract complications in liver transplant recipients: “Cast” in ischemia-type biliary lesions is bright in T1w P. Hunold1, S. Kinner2, A. DechГЄne2, T. Zoepf2, T.C. Lauenstein2, S.C. Ladd2, J. Barkhausen1; 1LГјbeck/DE, 2Essen/DE ([email protected]) Purpose: Biliary tract complications after liver transplantation (LTx) including ischemic type biliary lesions (ITBL) are common. However, ITBL remain a diagnostic challenge. “Cast” - bile tract obstructing epithelial cell debris - being one correlate of ITBL is difficult to detect with non-invasive imaging techniques. Aim of this study was to evaluate the accuracy of MRI for the detection of intrabiliary cast compared to endoscopic retrograde c holangiography (ERC). Methods and Materials: Fifty-nine patients (34 males; 49 p 14 years) suspicious of ITBL underwent ERC 640 p 991 days after cadaveric or living-donor LTx. Within 48 h prior to ERC, 1.5 T liver MRI was performed using the following protocol: T1w 2D FLASH, T2w HASTE, T2w TSE, 2D-RARE MRCP, navigator-gated 3D high-resolution MRCP, dynamic Gd-enhanced T1w 3D VIBE fs, T1w 2D FLASH fs post Gd. The different MRI sequences were compared to ERC in detecting ITBL and cast. Results: ERC confirmed ITBL in 28 cases, cast was found in 11 of those. ITBL was consistently confirmed and excluded by both, ERC and MRCP in 24 and 19 pts., respectively. In 14 pts., MRCP diagnosed ITBL while ERC did not. ERC detected cast in 14 pts., MRCP only in 5 of them, additionally yielding 4 false positives. However, pre-contrast T1w images detected cast as hyperintense structures in 11/14 pts with cast at ERC. Conclusion: Cast as a correlate of ITBL appears hyperintense on non-enhanced T1w images. The combination of MRCP and T1w sequences yields higher diagnostic value than MRCP alone making imaging of ITBL more reliable. 10:30 - 12:00 Room I Physics in Radiology SS 1013 New advances in CT Moderators: A. Noel; Vandoeuvre-les-Nancy/FR K. Perisinakis; Iraklion/GR B-511 10:30 CT image reconstruction with extended z-range R.P. Grimmer1, M. Oelhafen2, U.V. Elstroem3, M. KachelrieГџ1; 1Erlangen/DE, 2 Baden-DГ¤ttwil/CH, 3Aarhus/DK ([email protected]) Purpose: Extend the reconstructable z-range in cone-beam CT. Methods and Materials: For circular cone-beam CT the Feldkamp algorithm is most commonly used. In most applications projection data from 360В° or more are available. Usually only those slices are reconstructed where each pixel is viewed under the full 360В° range. Yet cone-beam reconstruction is possible whenever a voxel has been viewed by at least 180В°. There are slices that receive contributes from less than 360В° but from more than 180В°. These should be reconstructed in order to make better use of the dose and to extend the z-range. We developed and evaluated an algorithm that reconstructs also those slices: the extended Feldkamp algorithm (xFDK). In comparison to other algorithms that solve the same problem, xFDK does neither require multiple convolutions nor multiple backprojections and is therefore much more efficient. To evaluate xFDK we used the geometry of the Varian-OBI scanner (fan-angle=15В°, cone-angle=11В°, FOM=26 cm) but our findings also apply to other C-arm CT scanners. Simulated and clinical patient data were processed. Results: For our geometry, xFDK extends the z-range by 13% with nearly identical image quality. Image quality was evaluated in terms of image noise, spatial resolution and artifacts. xFDK was successfully applied to clinical patient data. Conclusion: xFDK increases the reconstructable z-range in a computational efficient way. Dose usage with xFDK is increased by 10 to 20% (depending on the scanner geometry) compared to standard Feldkamp approaches that are in use in today’s flat-panel CT scanners. Scientific Sessions B-512 10:39 A new method to assess spatial resolution in CT R. Grimmer, M. KachelrieГџ; Erlangen/DE ([email protected]) Purpose: To assess the point spread function (PSF) and the modulation transfer function (MTF) of a CT scanner using a single measurement and standard reconstruction parameters. Methods and Materials: To quantify the spatial resolution in CT, one typically performs separate measurements for the lateral and the longitudinal PSF. Many procedures further require reconstructions with very small voxel sizes, e.g. when wire phantoms are scanned. This, however, may already change the shape of the PSF. We propose to measure a sphere, perform a standard image reconstruction and evaluate profiles through the sphere surface. The radial symmetry of CT scanners allows to reduce the dimensionality of the PSF from three to two by radial averaging. It is shown in this paper that the resulting two-dimensional profiles can be decomposed into a radial and a longitudinal component by two-dimensional parallel-beam filtered backprojection. Our method was evaluated using simulations and flat panel cone-beam CT measurements of a homogeneous sphere. Results: The longitudinal and radial PSFs, and the corresponding MTFs, highly agree with those obtained with conventional methods, for both the simulations and the measurements. Figures of merit extracted from the curves, such as the full width at half maximum of the PSF or the 10% value of the MTF, differ by less than 5% between the new method and the conventional approaches. Conclusion: Our technique, which requires only one standard measurement and standard reconstruction of a sphere, accurately quantifies the spatial resolution of a CT system. Therefore, it appears as a superior alternative to existing methods. B-513 10:48 Improved cardiac CT angiography using a motion-compensation reconstruction technique U. van Stevendaal, J. von Berg, C. Lorenz, H. Schmitt, P. Forthmann, M. Grass; Hamburg/DE ([email protected]) B-514 10:57 A dedicated rawdata-based metal artifact reduction method for flatdetector CT D. Prell, Y. Kyriakou, W.A. Kalender; Erlangen/DE ([email protected]) Purpose: Metal implants cause non-linear artifacts in the reconstructed image. We evaluated the efficiency of a dedicated metal artefact reduction (MAR) approach for flat-detector CT (FD-CT). Methods and Materials: Our MAR approach uses 3D segmentation of the metal in the initially reconstructed 3D volume. Sub-volumes are backprojected onto the detector to identify the metal in the projection data and to replace it by 2D linear interpolation before reconstruction. Subsequently, standard Feldkamp reconstruction is performed. Performance was evaluated by phantom and patient measurements on a C-arm FD-CT system (Artis Zeego, Siemens Healthcare, Germany). Data was acquired B-515 11:06 CT metal artifact reduction with scout-view assisted metal localization S. Prevrhal1, G. Du1, T. Funk2, B.M. Yeh1; 1San Francisco, CA/US, 2Newark, CA/US ([email protected]) Purpose: Metal causes artifacts in CT images that can render them nondiagnostic. Localization of metal is the first step in most metal artifact reduction schemes and is often performed in natively reconstructed images at large computational cost. The hypothesis of our work was that simple CT scanogram (scout) views provide accurate localization of metal in the projection data without the need for preliminary native image reconstruction, cutting reconstruction time in half. Methods and Materials: Phantoms of one- and two-sided chrome-cobalt hip replacements with adjacent lesions were imaged on a 16-slice CT scanner. Userassisted segmentation of the hip prostheses in the scout views was transferred to the spiral data sets to identify metal sinusoidal trace regions. After automatic refinement of the metal traces they were replaced with per-projection linear interpolation of non-metal projections and edge-smoothing and reconstructed with either filtered backprojection (FBP) or iterative expectation-maximization reconstruction (EM). Performance was quantified by signal-to-noise (SNR) and percent accuracy error (PAE) by comparison to reference images with the prostheses removed in three representative regions of interest (ROIs). Results: Both EM and FBP metal artifact reduction reconstruction achieved satisfactory metal artifact suppression with average PAE errors of 4.5% and 5.5%, respectively versus 7.1% for native images and SNR improved to 40.3 (EM) and 21.1 (FBP) versus 16.5 (native). Conclusion: The new artifact suppression design adds minimal computational overhead to non-metal artifact reduction reconstruction and improves images so that previously obscured fine details are revealed. B-516 11:15 Hyperfast cone-beam spiral CT image reconstruction M. KachelrieГџ, S. Steckmann, M. Knaup; Erlangen/DE ([email protected]) Purpose: To increase the reconstruction speed for exact and approximate conebeam spiral CT image reconstruction. Methods and Materials: Cone-beam spiral CT image reconstruction is computationally highly demanding. Most computations are required for the backprojection. Compared to reconstructions from circular scans there is a significant complication: the illumination of each voxel, i.e. the range of angles the voxel is seen by the X-ray cone, is a complex function of the voxel position. A voxel-specific weight w (x, y, z, a) needs to be multiplied to each voxel (x, y, z) at each projection angle a. This weight function has no analytically closed form and must be determined numerically. Storage of the weights is prohibitive due to the large number of entries. We propose an algorithm that utilizes the spiral symmetry and removes the z-dependence from w which now reduces from a 4D to a 3D function. Image quality is evaluated using a clinical cone-beam reconstruction algorithm combined with our new backprojection approach to reconstruct patient data acquired with a clinical CT scanner. Results: Our backprojection processes 81 images per second (5122 pixels) on a standard PC. It is 11x faster than our optimized reference reconstruction that does not make use of the spiral symmetry. Spatial resolution and image noise are identical to the reference images. Visually, the patient images do not show any differences. Conclusion: Hyperfast spiral cone-beam CT image reconstruction is possible with standard PCs using our approach. The speed-up can also help to bring iterative image reconstruction with reduced patient dose levels to clinical routine. A B C D E F G H S257 Sunday Purpose: Challenges for image reconstruction in cardiac CT arise from the rather fast cardiac motion and inconsistent data that are associated with cardiac gating combined with helical scanning. We present a motion-compensated reconstruction (MCR) method that can suppress motion blurring and yield improved data utilization, which can either increase the signal-to-noise ratio (SNR) or lower the required dose for retrospective gating. Methods and Materials: As a first step, low-pitch helical data are reconstructed at low resolution at numerous phase points through the cardiac cycle. As a second step, an automatic cardiac adaptive surface model is applied to each reconstructed phase and, from these surfaces, a motion-vector field is calculated for each voxel in the region of interest. Finally, a motion-compensated reconstruction is carried out using those projections, which cover the cardiac phases for which the motionvector field has been determined. The method has been successfully applied to clinical data sets acquired with a Philips Brilliance 64 CT scanner. Results: Motion artifacts are reduced clearly and coronary arteries can be depicted appropriately even in phases of relatively strong motion. Since larger gating windows can be used for reconstruction without loss of sharpness, the images show a better SNR than results obtained with reconstruction algorithms without compensating the motion. Conclusion: Motion-compensated reconstruction is feasible by employing 4D heart model adaptation for the motion estimation. The method has the potential to offer significant improvement in the imaging of the heart and to provide 4D object motion information for functional analysis. for tissue-equivalent phantoms (QRM GmbH, MГ¶hrendorf, Germany) and different human body regions. Accuracy of correction (spatial resolution, noise) was investigated in subtraction and noise images and by comparison of reference images without metal inserts. Different regions of interest (ROIs) were evaluated for noise assessment and CT value consistency. Results: Metal artifacts were efficiently reduced both in phantom and patient images and a comparison of CT values of the corrected with the reference image confirmed consistent CT values (deviations of up to 800 HU were reduced to below 40 HU). Noise reduction to the noise level measured in the corresponding reference image was achieved in a similar manner. No resolution losses were caused in areas at a distance greater than 2 mm to the implant. Detectability of low-contrast objects was improved. Conclusion: MAR can improve the quality of FD-CT images containing metal artifacts and allow medical diagnosis of areas close to the metallic prosthesis. Scientific Sessions B-517 11:24 Advanced statistical reconstruction algorithm for CT dose reduction J. Hsieh, F. Dong, J. Fan, B. Li, M. Kulpins, J.-B. Thibault, X. Tang; Waukesha, WI/US ([email protected]) Purpose: CT dose reduction is an important issue. Although iterative reconstruction (IR) offers substantially improved image quality at reduced dose, computational complexity is beyond the reach for many applications. We present an advanced statistical reconstruction (ASR) that offers significant dose reduction while providing reconstruction speed suitable for daily clinical usage. Methods and Materials: We first condition the projections to remove bias introduced in the logarithmic operation under photon starvation conditions. An initial image based on the filtered backprojection (FBP) is generated and image update operation is performed in two sequential steps: an iterative regularization and an image update based on comparison between measured and synthesized projections. Simplified system matrix is used for speed. The update process stops after a pre-determined criterion is met. ASR is significantly different from existing IR in which both the difference and the regularization terms are used to produce the cost function for updating. Results: Phantom and patient studies were conducted. Phantom studies show that ASR offers a 50% dose reduction while maintaining spatial resolution compared to an FBP algorithm. Clinical studies demonstrate that ASR produces images of similar quality at half the radiation dose as compared to FBP at full dose. ASR was implemented on a hardware that generates images at significantly higher than 10 images/s. Conclusion: We present an ASR algorithm that offers significant dose reduction while maintaining image quality. ASR provides better visualization of small anatomical structures as compared to FBP. Its computational advantage over conventional IR algorithms is demonstrated. B-518 11:33 A novel spatiotemporal filter for artifact and noise reduction in CT R. Raupach, H. Bruder, B. Schmidt, E. Klotz, T.G. Flohr; Forchheim/DE ([email protected]) Purpose: To reduce the radiation dose of CT perfusion scans and dynamic CTAs and to improve the CT number stability for cardiac perfusion exams. Methods and Materials: We present a new spatiotemporal filter (STF) with various applications. After reconstructing a time series, images were decomposed into multiple spatial frequency bands (FBs). A temporal convolution was performed separately for each band with FB-dependent filter width. Final images were derived by recombining the FBs. Two different applications were examined: (1) For CT perfusion or dynamic CTAs, narrow (broad) temporal filters were used at low (high) frequencies in order to preserve the temporal resolution of the time density information, but reduce pixel noise. (2) For cardiac perfusion, different cardiac phases were reconstructed as a time series. As opposed to 1, temporal convolution was broad (narrow) in the low (high) FBs in order to preserve details at maximum temporal resolution. Results: Method 1 allowed for noise reduction of typically 60%, or equivalently, increasing the contrast to noise ratio (CNR) by a factor of 2.5. The time density function was significantly improved in terms of statistical fluctuations without deteriorating its temporal resolution. Method 2 reduced CT number variations due to partial scans by a factor of 3, yielding more accurate time density information. Conclusion: The STF improves image quality for dynamic CTAs and CT perfusion, which can be utilized in terms of radiation dose reduction or increased spatial resolution at the same CNR. In the second operation mode, more accurate cardiac perfusion evaluation is enabled by the STF. B-519 11:42 Evaluation of concepts for spiral CT imaging with high-pitch values in DSCT D. Ertel1, H.-J. Lee1, J.U. Krause1, T. Flohr2, W.A. Kalender1; 1Erlangen/DE, 2 Forchheim/DE ([email protected]) Purpose: For dual-source CT systems, scan time per volume can be decreased and temporal resolution increased. Just the same, pitch values can be increased compared to single-source CT systems. We evaluated the performance of spiral CT with pitch values of up to 3.0. Methods and Materials: Measurements were performed using a dual-source CT (SOMATOM Definition, Siemens, Forchheim) with 0.33 s rotation time for pitch values of 0.35, 0.5, 1.0, 2.0 and 3.0. We assessed the slice sensitivity profile (SSP) and the temporal modulation transfer function (t-MTF) [Ertel et al. Radiology 2008; 248 (3) 1013-1017]. Additionally, scanning of the cardiac region was performed in S258 A B C D E F G F H pigs, which were scheduled for cardiac exams, with a pitch value of 3.0 for visual assessment. Results: Resolution in the z-direction remained essentially constant even for increased pitch values with a slight decrease for a pitch of 3.0; the 10% value of the MTF curve of the SSP amounted to 12.30 (p = 0.35), 12.09 (p = 0.5), 12.39 (p = 1.0), 12.03 (p = 2.0) and 11.41 (p = 3.0) [lp/cm]. The in-plane t-MTF was not affected by the pitch value meaning constant temporal resolution independent of pitch. CT images of the in-vivo pig scans confirmed good image quality at p = 3. Conclusion: CT imaging with a pitch value of up to 3.0 can provide unimpaired image quality with respect to spatial and temporal resolution in DSCT. Scan time can thereby be decreased significantly. Applications to cardiac imaging with lower dose appear possible. B-520 11:51 Ring artifact correction methods for flat-detector CT D. Prell, Y. Kyriakou, W.A. Kalender; Erlangen/DE ([email protected]) Purpose: Imperfect calibration or defect detector elements may cause concentric ring artifacts in CT images. We evaluated two ring artifact correction methods for flat-detector CT (FD-CT) and their effectiveness in phantom studies and in clinical examples. Methods and Materials: We present a comparison of two post-processing ring artifact correction methods for FD-CT, based on different thresholds and adaptive, distance-depending median filterings of the reconstructed slices. While the first method works in Cartesian coordinates, the second performs a transformation to polar coordinates. Measurements were performed on a C-arm FD-CT system (Artis Zeego, Siemens Healthcare, Germany). In a water phantom, standard deviations and CT values were measured in central and peripheral regions of interest (ROIs). The correction algorithms were applied to measurements with different acquisition angles, i.e. partial scan (218°) and full scan (360°) and different detector pixel binning (1 x 1, 2 x 2 and 4 x 4). Patient data sets were used for performance validation. Results: Ring artifacts were efficiently reduced both in phantom and patient data. Standard deviations corresponding to image noise were reduced by up to 20%. Homogeneity (IEC 61223-3-5 standard) was increased by 25%. Correction worked superior in 360° scans compared to 218° scans for both methods. The best image quality was achieved using polar coordinates for correction, but needed additional computational time. Conclusion: Both correction methods improve the quality of FD-CT images containing concentric ring artifacts with negligible impact on image resolution and at acceptable computational costs. The correction via polar coordinates worked superior to correction in Cartesian coordinates. 10:30 - 12:00 Room K Pediatric SS 1012 Fetal and neuro imaging Moderators: O. Flodmark; Stockholm/SE R.R. van Rijn; Amsterdam/NL B-521 10:30 Fetal cardiovascular MRI: Steady-state free precession sequences and angio-MR sequences for the management of fetuses with congenital cardiac malformations S. Savelli, M. Di Maurizio, A. Tomei, F. Fierro, F. Ventriglia, L. Manganaro; Rome/IT Purpose: To assess the feasibility of steady-state free precession sequences (SSFP) sequences and angio-MR sequences to evaluate congenital heart disease (CHD). Methods and Materials: A total of 43 pregnant women with 43 fetuses with a previous diagnosis of congenital heart disease were examined using fetal MRI with SSFP static and dynamic images to evaluate the heart and vessels and with T1 GE angio-MR sequences to assess the aorta. Both direct and indirect signs of CHD were investigated and in all cases MRI findings were compared with postnatal echocardiograms or autoptic findings considered as the standard of reference. Results: A cardiac disease was diagnosed in 42/43 fetuses by postnatal echocardiograms (40) and autoptic findings (2) and disclosed in 1 fetus. In all cases, MRI imaged the fetal heart identifying cardiac anomaly in 38 fetuses, missing the diagnosis in 4 fetuses and disclosing the pathology in1 fetus. In two fetuses Scientific Sessions with ventricular septal defects, angio-MR excluded a possible association with coartaction of the aorta; in one fetus with a hypoplastic left heart syndrome, angio-MR detected an associated coartaction of the aorta. Direct signs permitted the diagnosis in 24 fetuses, both direct and indirect signs in 7 fetuses and only indirect signs in 9 fetuses. Conclusion: Fetal cardiovascular MRI evaluation is a valuable tool to investigate abnormal cardiac conditions and to corroborate US diagnosis and exclude possible associated cardiac and extracardiac abnormalities. B-522 10:39 Assessment and imaging features of lymphangiomas in fetal MR C. Koelblinger, P.C. Brugger, S. Nemec, D. Bettelheim, C.J. Herold, D. Prayer; Vienna/AT ([email protected]) B-523 10:48 MRI with diffusion-weighted imaging and apparent diffusion coefficient assessment in the evaluation of placental changes during gestation F. Fierro, A. Tomei, M. Di Maurizio, F. Coratella, S. Savelli, L. Manganaro; Rome/IT Purpose: To investigate the placental ageing evaluating the changes of signal intensity and the measurement of placental tissue apparent diffusion coefficient (ADC) value of normal placenta in relation to various gestational ages. Methods and Materials: A total of 102 pregnant women (Age range 18-44, mean 29 years) with 105 fetuses (gestational age range 19-40, mean 25 weeks) underwent MRI for suspected disorders in several organs. A multiplanar study of fetuses was obtained by using T2-weighted sequences and echo planar imaging (EPI); notwithstanding the diagnostic question, in every study also the placenta was included. Diffusion-weighted images and ADC maps were evaluated and placental tissue ADC value was calculated for all fetuses divided into three groups based on gestational age (I group: from 20 to 26 gestation week; II group: 27-33; III group: 34-40). Patients with suspected utero-placental insufficiency or placental anomalies were excluded. Results: In the quantitative evaluation of normal placenta, MRI showed an inverse correlation between ADC values on ADC maps and gestational age (GA). ADC values had a range from 800 to 2,500 µm2/s and showed a decrease in the first group, a stationary phase in the second group and a new decrease in the third one. Moreover, a qualitative evaluation of diffusion-weighted images demonstrated that the signal intensity of the normal placenta appeared more hypointense in relation with the placental ageing. Conclusion: Diffusion-weighted imaging (DWI) with ADC mapping can be useful for the evaluation of normal placenta and may become a tool of assessing normal placental development by measurement of placental tissue ADC values. 10:57 Fetal functional MRI on 1.5 T and 3 T: Changes of R2* in the fetal brain and lung during hypoxia M. Frisch, J. Yamamura, H. Kooijman, K. Hecher, G. Adam, U. Wedegaertner; Hamburg/DE ([email protected]) Purpose: To compare delta R2* in the brain and the lung of fetal sheep during hypoxia obtained with different field strength (1.5T versus 3.0T). Methods and Materials: Measurements of the fetal sheep brain and lung were performed on 17 pregnant ewes at a 1.5T (n = 8) and a 3.0T (n = 9). On both scanners, a T2*-weighted single-shot gradient-echo EPI-sequence (3.0T: TE = 30 msec, 1.5T: TE = 50 msec) was used to measure T2*-weighted images ($R2*) in the brain and lung of the fetal sheep during control and hypoxia. Fetuses were chronically instrumented with a carotid catheter to measure the fetal arterial oxygen saturation (FetSO2). $R2* was correlated with FetSO2, and linear regression analysis was performed. Results: A total of 32 examinations on 17 ewes were performed (1.5T: n = 7 brains, n = 7 lungs; 3.0T: n = 9 brains, n = 9 lungs). At 1.5T, FetSO2 was reduced from 84% during control to 10% during hypoxia. The $R2* was -3.9 1/s in the brain and -5.4 1/s in the lung. At 3.0T, the FetSO2 was reduced from 71.2% during control to 8.7% during hypoxia. The $R2* was in the brain -5.8 1/s in the brain and -6.9 1/s in the lung. $R2* in brain (1.5T: r = 0.93, p = 0.0005; 3.0T: r = 0.82, p = 0.0007) and lung (1.5T: r = 0.61, p = 0.04; 3.0T: r = 0.86, p = 0.0003) correlated significantly with FetSO2. Conclusion: At both field strengths an alteration of the BOLD signal intensity during hypoxia was identified in fetal brain and lung. Changes in $R2* in the brain and lungs are proportional to the field strength. B-525 11:06 Human ear development demonstrated by in-vivo fetal MR N. Hachemian, P. Brugger, M. Weber, D. Prayer; Vienna/AT ([email protected]) Purpose: The aim of this study was to illustrate the development of the fetal ear with MR metric data. Methods and Materials: A total of 208 unsedated fetuses from singleton pregnancies with assumed normal auditory development were examined on a 1.5 T unit using T2-weighted 2-4 mm thick coronal sections through the temporal bone. Five age groups were defined: A: 16-20 gestational week (GW), B: 21-25 GW, C: 26-30 GW, D: 31-35 GW and E: from 36 GW until the date of birth. Measured parameters included the length of the auricle (LA), the widest diameter of the cochlea (WDC), the semicircular canals and ducts (WDSCD) and the largest width of one semicircular duct (LWSD). Results: The mean LA differed significantly between group A (11.25 mm) and C (17.27 mm), A and D (19.07 mm), A and E (22.47 mm), and B (14.85 mm) and E (22.47). The WDC (A: 4.82 mm, B: 4.77 mm, C: 5.05 mm, D: 5.08 mm and E: 4.85 mm) did not differ significantly between the groups. The WDSCD showed significant differences between A (10.83 mm) and C (13.60 mm), A and D (14.99 mm) as well as between A and E (15.99 mm). Furthermore, the comparison between B (12.24 mm) and D (14.99 mm), B with E (15.99 mm) and that of C (13.60 mm) with E (15.99 mm) showed siginificant differences. The LWSD showed no significant difference in the post-hoc test by Hochberg between A (2.44 mm), B (2.68 mm), C (3.07 mm), D (3.63 mm) and E (3.08 mm). Conclusion: The presented normal values will be helpful in the evaluation of fetal ear pathology. However, larger sampling sizes will be necessary to define percentile curves. B-526 11:15 MR imaging of intra- and extracranial haemorrhage in the neonate: Birth injury or non-accidental injury? L.I. Wallis, S.V. Gandhi, M.F. Smith, M.N.J. Paley, P.D. Griffiths, E.H. Whitby; Sheffield/UK ([email protected]) Purpose: Subdural haematomas in infants are associated with non-accidental head injury. We sought to establish the frequency and natural history of subdural haemorrhages in asymptomatic term neonates and whether the presence of intracranial bleeds is reflected in an increased number of extracranial bleeds and if the delivery method influenced this. Methods and Materials: Term babies were imaged within 48 hours of delivery using a 0.2 T MRI scanner. Obstetric details were recorded retrospectively from the patient’s notes. A neonatal radiologist recorded the incidence of subdural or subgaleal haemorrhage and cephalohematoma. Statistical analysis used normal vaginal delivery (NVD) as the baseline. A B C D E F G H S259 Sunday Purpose: To evaluate the imaging findings of lymphangiomas diagnosed with fetal MRI. Methods and Materials: MR scans of six fetuses with postnatally proven lymphangiomas were evaluated. MR imaging was performed between the 18th and 35th gestational week at 1.5 T using a cardiac phased-array coil. MR evaluation included: number, size and signal intensities (T1w ,T2w, EPI) of the cysts, thickness of the septae, margins, presence of blood breakdown products, change in size or signal intensity (three patients with multiple examinations), exact expansion of the lesions to the adjacent anatomical structures and concomitant pathological findings. Results were compared with postpartum clinical assessment and MR or ultrasound in five patients. Histologic specimens were available in three patients. Results: One retroperitoneal, two thoracic and three cervical lymphangiomas (diameters between 3.3 and 12 cm) were found in our series. All lesions consisted of macrocysts and additional solid appearing parts were found in three lymphangiomas. Blood breakdown products were found in one lesion. Two patients showed concomitant pathologies. Concerning tumor expansion, agreement with postpartal imaging and/or surgery was excellent. In cases with cervical lesions, the trachea was not distorted, making an EXIT procedure unnecessary. One pregnancy was terminated on the basis of imaging findings. Conclusion: Fetal lymphangiomas display the same MR features as postnatal ones. Intrauterine MR characterization of such lesions include exact delineation, detection of associated and/or concomitant pathologies and differential diagnosis against other cystic pathologies. Patient management may be altered with respect to the type and/or time of treatment, and to the continuation or termination of pregnancy. B-524 Scientific Sessions Results: Imaging of 494 neonates: NVD (n = 269), forceps (n = 35), ventouse (n = 65), failed ventouse and subsequent forceps (n = 29), elective caesarean section (n = 49) and emergency caesarean section (n = 47) revealed 38 subdural haemorrhages (7.7%). Of these, 19 were NVD, 3 forceps deliveries (odds ratio = 1.23), 6 were forceps after attempted ventouse delivery (OR = 3.4; P = 0.02), 8 followed ventouse delivery (OR = 1.96) and one followed emergency caesarean section (OR = 0.38). All had resolved by the 4 week rescan with no reoccurrence to date. The distribution of subgaleal haemorrhage (n = 18) and cephalohaematoma (n = 11) followed that of subdural haemorrhage. Conclusion: High numbers of clinically silent intracranial and extracranial haemorrhages occur most frequently in instrumental deliveries and resolve spontaneously without detrimental effects within 4 weeks. Subdural haemorrhages after 4 weeks of age are therefore not related to birth injury and traumatic causes must be considered. B-527 11:24 Periventricular leukomalacia in preterm children: Gray and white matter and cerebrospinal fluid changes assessed with MRI L.C. Tzarouchi, L.G. Astrakas, A.K. Zikou, V. Xydis, P. Kosta, S. Andronikou, M.I. Argyropoulou; Ioannina/GR ([email protected]) Purpose: To assess total volume of GM, white matter (WM) and cerebrospinal fluid (CSF) and individual volume of 116 GM areas in patients with PVL. Methods and Materials: Using a T1-weighted three-dimensional spoiled gradientecho sequence, total GM, WM and CSF volume was evaluated in 10 preterm born subjects (gestational age 31.7p4.2 weeks and corrected age 27.8p21.7 months) with MRI findings of PVL and in 46 age-matched preterm controls. Volumes of 116 GM areas were calculated after their segmentation using the Statistical Parametric Mapping (SPM5) and the Individual Brain Atlas Statistical Parametric Mapping (IBASPM) software packages. Results: Total CSF volume was higher (300.8p56.2 cm3) and WM volume was lower in PVL patients (182.1p40.5 cm3) than in normal subjects (219.0p61.8 cm3, 222.9p67.2 cm3, respectively), p 0.05. No significant difference was found in total GM volume. Significant volume differences were found between patients and controls in specific GM areas: Frontal Superior Orbital 3.6p0.6 cm3, 3.1p0.7 cm3, p=0.03, Posterior Cingulum 2.0p0.5 cm3, 1.5p0.2 cm3, p 0.001, Lingual 9.7p1.7 cm3, 8.2p1.3 cm3, p=0.003, Putamen 2.5p0.6 cm3, 1.7p1.4 cm3, p 0.001, Thalamus 2.6p0.9 cm3, 1.8p0.4 cm3, p 0.001, respectively. Conclusion: Patients with PVL present increased CSF and decreased WM volume. GM segmentation reveals increased volume of the putamen, thalamus and of individual GM areas related with the WM the most affected from PVL. Development of extensive cortical connections and/or persistence of transient fetal connections may be proposed as a mechanism of brain reorganization. B-528 11:33 Age related gray matter changes in preterm subjects: A MRI study L.C. Tzarouchi, L.G. Astrakas, A.K. Zikou, M. Papastefanaki, V. Xydis, S. Andronikou, M.I. Argyropoulou; Ioannina/GR ([email protected]) Purpose: To assess individual volume of 116 GM areas in normal preterm born children. Methods and Materials: Sixty seven preterm born children (corrected age: 12.7p9.9 months, gestational age: 32.9 p2.3 weeks) with normal structural MRI were included in the study. Using a T1-weighted high resolution three-dimensional spoiled gradient echo sequence, volumes of 116 GM areas were calculated after their segmentation using the Statistical Parametric Mapping (SPM5) and the Individual Brain Atlas Statistical Parametric Mapping (IBASPM) software packages. Non linear regression analysis assessed age dependency of volume data for every GM area. The model used was the monoexponential function y=A-B*exp (-x/C) where y: volume at corrected age x, A: volume at the end of maturation, B: total change and C: rate of change. The 99% of the final volume (A99%) was reached at time t (99%) =-C*ln (0.01*A/B). Results: All supratentorial GM areas followed the monoexponetial function model reasonably but the pallidum and cerebellar structures had a poor goodness of fit. Volume increase of the individual GM areas followed a caudal to cephalad and a dorsal to ventral pattern. Thalamus, putamen and caudate nucleus reached A99% earlier than most cortical GM areas. Visual cortex, postcentral and precentral cortices reached A99% earlier than parietal, frontal and temporal cortices. Conclusion: GM volume changes follow age related maturational changes of the regional white matter. Maturation of white matter tracts connecting cortical and subcortical GM may be at the base of GM volume increase. S260 A B C D E F G F H B-529 11:42 Hypoxia, intradural hemorrhage and subdural bleeding in the pediatric and perinatal post-mortem - are they related? A study combining the use of autopsy and post mortem magnetic resonance E.H. Whitby, A. Sprigg, M. Cohen; Sheffield/UK ([email protected]) Purpose: To describe the occurrence of intradural (IDH) and subdural (SDH) hemorrhage in pediatric and perinatal deaths using a combined approach with autopsy, histology and post mortem magnetic resonance (PM MRI). Methods and Materials: Retrospective review of the post mortem examination and PM MRI findings in the central nervous system of 42 cases. The MRI was conducted with a 1.5 T magnet with fast spin-echo T2 weighted images. The gross dissection of the brain was performed using a posterior approach. The brain and spinal cord were fixed in 20% buffered formalin at 37° for 4 to 6 days before histology. Results: Acute hypoxia was present in 14/42 cases on the histology and the PM MRI. IDH was identified by histology in 35 cases: diffuse in 17 and focal in 18 cases. 12/17 cases with diffuse IDH were less than a week old. IDH was either more prominent or only present in the posterior falx and tentorium. Eleven cases (all with diffuse IDH on histology and 10 with features of hypoxia on histology and at PM MRI) had a small SDH seen at autopsy and on PM MRI. Conclusion: IDH is not an uncommon finding in the pediatric and perinatal post mortem. When diffuse, IDH was frequently associated with hypoxia. In 12 of 17 cases with diffuse IDH, there was also an SDH. Further studies are needed to confirm the cause of our observed association among hypoxia, IDH and SDH hemorrhage in children dying of natural causes. B-530 11:51 A new image database on physiological brain iron accumulation in pediatrics: An in vivo MR study using susceptibility-weighted phase imaging T. Nishiguchi, K. Mochizuki, Y. Inoue; Osaka/JP ([email protected]) Purpose: To better understand disease-related, excessive iron deposition in the brain, it is necessary to know the physiological course of ferrous iron accumulation. The purpose of this study was to establish baseline phase data for brain tissues by susceptibility-weighted phase imaging (SWI-&). Methods and Materials: Forty-four pediatric patients (M:F=32:12, range in age 0-22) were examined at 1.5 T using SWI-& (TR/TE/flip angle: 48/40/20; resolution: 0.7, *0.9, *1.6 mm). The regions evaluated were the both sides of motor cortex (MC), putamen (PUT), globus pallidus (GP), caudate nucleus (CN), thalamus, (T), substantia nigra (SN), red nucleus (RN) and dentate nucleus (DN). Phase shift data were analyzed by age, gender, and hemispheric factors for each region using a biochemical mixed linear model (BM). Results: At birth, no accentuated phase shift due to iron was noted on SWI-&. Positive phase shifts due to iron accumulation were first detected at 4.5, 37, 23, 56, 67, 35, 56, and 106 months in the MC, PUT, GP, CN, T, SN, RN, and DN, respectively. These were significantly earlier than those on spin-echo T2-weighted images (SE-T2). There was no statistically significant effect by gender or the hemispheric factors. A correlation between phase shifts and the BM suggest the possibility of detecting iron below 5 mg/dl, a significantly lower level compared to 10 mg/dl on SE-T2. Conclusion: SWI-& is highly sensitive for detecting physiological iron content in the brain and would provide a new imaging baseline for disease-related iron deposition and gray- and white-matter contrasts. Scientific Sessions 10:30 - 12:00 Room L/M Radiographers SS 1014 Education and quality control Moderators: M. Golebiowski; Warsaw/PL K. Knapp; Exeter/UK B-531 10:30 A new model of trauma training and simulation for radiographer students L.I. Hansen, I.-J. Aandahl, K.G. Vikestad, J.B. Dormagen; Oslo/NO ([email protected]) B-532 10:39 From harmonics to harmonisation: European ultrasound education J. Dodgeon1, A. Sykes1, R. Ribeiro2, L. Lanca2, T. Johannesen3; 1Salford/UK, 2 Lisbon/PT, 3Oslo/NO ([email protected]) Purpose: The purpose of this study is to create awareness on the theory of medical abdominal diagnostic ultrasound, to create awareness on the opportunities for advanced practice, to assist the teaching staff in developing their skills and competencies and to develop provision within their own countries and to initiate development of joint European courses. Methods and Materials: The current usage of diagnostic ultrasound has created a rising demand in training for ultrasound users. This, allied with a lack of uniformly accepted standards, creates a potential problem for ensuring future operator competency and therefore accuracy of medical interventions. To help address these problems, we developed a 2-week iIntensive programme supported by EU funding from the lifelong learning programme, and aimed at postgraduate health-care practitioners from European countries with different approaches to ultrasound practice and education. This ground-breaking course also offered the development of opportunities for staff members of the partner institutions, since joint course design and delivery enable sharing of educators’ skills and competencies. Results: The 2-week intensive programme was delivered at the University of Salford in the UK and attended by students from the UK and from institutions in Norway, Portugal, and Sweden. Overall, student evaluations were very positive; 100% felt the course increased their knowledge of physics and the “core skills” for diagnostic ultrasound, and most (77-92%) thought their knowledge and skills had improved. Conclusion: The highly positive evaluations and outcomes of this project have stimulated much interest across participant institutions and countries, and prove the value of international healthcare education. 10:48 Tuning learning outcomes and competences for radiography courses in Europe A. Henner1, A. Vinorum2, V. Challen3, A. Vieira4; 1Oulu/FI, 2Oslo/NO, 3Lancaster/UK, 4 Lisbon/PT ([email protected]) Purpose: Degree profiles in radiography vary throughout Europe, including requirements for first post-competencies arising from different national traditions and ways in which the profession has developed. The Higher Education Network for Radiography in Europe (HENRE), through the use of the tuning methodology, has spearheaded recommendations and descriptors for radiography competencies and learning outcomes for the first and second higher education tuning cycles. Methods and Materials: An electronic questionnaire with rating scales for subjectspecific and generic competencies based on the results of the HENRE I project was completed by academics, students and clinicians in European countries. A number of other stakeholders were consulted, including radiography societies and universities providing wide professional and educational experience. Results: Recommendations for expected work loads expressed in ECTS for first and second cycles with an explanation as to the differences between clinical practice and clinical placement are made. The questionnaire (795 answers from 18 counries) showed that all specific competencies received scores higher than 2.96 (scale 0-4) for 1st cycle education with a high correlation among academics, students and clinicians. Groups gave high scoring to competencies related to optimizing radiation dose management, informing and instructing patients appropriately and team work. For generic competencies, the following were scored higher than 3.66 (scale 0-4) for all three groups showing a high correlation i.e. the capacity for applying knowledge in practice and concern for quality Conclusion: The tuning template for radiography provides recommendations for expected workloads including scientific areas in the curriculum and the identification of generic and subject competencies. B-534 10:57 Self-assessment as a part of clinical audits in radiology A. Henner, S. Mattila, M. Huovinen, A. Servomaa; Oulu/FI ([email protected]) Purpose: Radiological units in Finland have been audited once. Now, the second audit cycle is going on. One of the key areas is self-assessment. The purpose of this study is to point out by examples how to make self -assessment in radiological X-ray departments as a part of clinical audits. Methods and Materials: Radiographers and radiologists produce optimisation of image quality and dose in several health centres as a part of everyday work. Dose optimisation is done by different methods: by using programs of the equipments, by regulating the AEC (automatic expose control) and critically analysing the use of grid. Results: Self-assessment can be done by analysing own, present practices, improving and testing them and by making a valid documentation. Digital imaging technique offers a lot of possibilities to optimise dose and image quality e.g., in digital mammography by using low dose technique instead of standard. In Lumber spine lateral examination, 16% and in hip joint 27% dose decrease was achieved by testing the AEC and using its possibilities (plus /minus) in a proper way. The use of air gap (30 cm) instead of a grid in hip joint axio- lateral project decreased skin dose by two-- thirds. PACS system offered opportunity to analyse the quality of images afterwards. Conclusion: Self-assessment is a part of everyday work. All members of the staff as a team should do it regularly, in different areas. It is useful, gives new ideas and offers a possibility to develop the quality of your own department. B-535 11:06 The role of clinical assessment in radiography education across Europe M.D.J. Davis; Dublin/IE ([email protected]) Purpose: Explore the role of clinical asessment in radiography education across Europe. Methods and Materials: To identify if there is a clinical assessment system in place. To identify whether such a system is formal or informal. If it is formal, how does it impact on the students exit qualification. To identify who undertakes the assessment and if they are trained for the role. The aim of this investigation was to identify the role of clinical assessment in radiography education across Europe. A questionnaire was devised by members of the subgroup and placed on the HENRE website. Higher education institutions (HEIs) offering courses in radiography across Europe were requested to access the website and complete the questionnaire. Results: A total of 27 replies were received and analysed. The results demonstrated that all students undertake a formal system of clinical assessment of their practice A B C D E F G H S261 Sunday Purpose: To measure the learning effect of trauma simulation training for radiographer students. Methods and Materials: A 2.5-day long trauma course was tailored for 46 third year radiographer students from the local University College. We involved experienced professionals in lectures and practical training. In the simulation centre of a major Scandinavian trauma hospital, a realistic trauma scenario was presented for each group of two students. The students were set tasks related to various difficulties: acquisition was disturbed, exposure was inferior, organs were cut on the film, patient was getting unstable and the team leader was getting impatient. X-ray exposure was simulated and samples of acquisition failures were demonstrated. Debriefing with a positive focus was performed afterwards. A questionnaire (1-no agreement to 5-thorough agreement) on the evaluation of the course relevance, trauma understanding, the students’ self-evaluation and the teachers’ ability to encourage the students was filled up. The control group consisted of 19 radiographer students who had undergone standard trauma education at another radiographer college. Results:The comparison between the trauma simulation group and the control group revealed significant differences in rating the relevance of the trauma education (4.8 versus 2.4), the educational contributions to trauma understanding (4.7 versus 2.6), the self-evaluation of being part of the trauma team (3.7 versus 2.0) and the teachers’ ability to encourage the students to learn more about trauma (4.3 versus 1.9, all P 0.001). Conclusion: Trauma simulation training for radiographer students revealed a considerable learning effect. This concept should be integrated into standard radiographer education programs. B-533 Scientific Sessions in order to determine if they are competent to practice. This followed a period of clinical practice which ranged from 385 hours to 2400 hours. All institutions had a system of assessment which the student has to pass to be able to practice in radiography. There was a wide range of marks awarded for clinical assessment which contributed to their qualification. This ranged from 0% up to 50% of the award. Clinical assessments were undertaken by trained assessors in the vast majority of cases (93%). These assessors were from both the clinical department and academic institutions in almost equal proportion. Conclusion: All students undertook a formal clinical practice assessment as a requirement to practice once qualified. The range of hours for their clinical experience was vast ranging from 385 to 2400 hours. Ninety-three percent of all assessors were trained for their role by a formal system of training and the assessment role was undertaken by both clinical and academic staff in equal proportions. B-536 11:15 Common assessment scheme for undergraduate radiographers in the north of England K.G. Holmes1, S. Boynes2, C. Sloane1, A. Westmoreland3, N. Crohn3, A. Newton-Hughes4, A. Hyatt5, M. Elkington5, H. Robinson6; 1Lancaster/UK, 2 Bradford/UK, 3Leeds/UK, 4Salford/UK, 5Sheffield/UK, 6Preston/UK ([email protected]) Purpose: In 2006, the Northern Group of Universities delivering undergraduate education met to discuss the assessment of students’ clinical skills in the hospital environment. It was decided that the system at all universities could be improved and a common assessment �tool’ should be devised to improve this element of clinical assessment. Methods and Materials: Programme leaders and clinical coordinators from universities met to discuss the value and efficacy of their undergraduate workplace clinical assessment tool. It was decided that most of the current tools used had areas for development to enable them to better discriminate clearly between students who were safe to practice and those who were not. Over a period of 18 months, an assessment tool was developed to assess the student’s safe and proficient practice in the workplace. The tool was refined at two regional meetings where delegates from the participating universities, radiographic departments, service users and the Strategic Health Authority were represented. After the initial pilot, the tool was refined and will be re-evaluated. Results: A common workplace assessment tool was devised, which is either being piloted or adopted in seven universities in the North of England. Conclusion: The presentation illustrates how universities can work collaboratively to develop a common clinical skills assessment tool for radiography. The assessment tool has been well received by clinical staff and students and appears to be a robust and effective tool for assessing the proficient practice of students in the hospital environment. B-537 11:24 The importance of feed-back due to the quality in radiographers’ image production K. Hillergård; Jönköping/SE ([email protected]) Purpose: Digitalisation of X-ray departments has influenced contact between radiologists and radiographers. The radiologist might even be situated in another country making evaluation. Communication has been regarded important to obtain and increase image quality. A fear has been presented among radiographers that lack of feed-back might have negative consequences in image quality and knowledge development. The aim of this paper is to find out whether feed-back is necessary and how. This is a new research field. Much has been written about importance of feed-back, however, not connected to radiographers and digitalisation. Methods and Materials: A qualitative ethnographic approach is used. This method is effective to investigate custom and silent knowledge. By using open-ended interviews and observations the possibilities to focus both in details and comprehensive perspectives is possible. What are the objectives making the radiographer content with the exam? Is feed-back given today, how and what is regarded necessary? Results: Analyze was made by using Actors Network Theory. The result shows a huge complex heterogeneous network regarding objectives of satisfaction. Communication with radiologist, colleagues and patient and also documentation and feed-back is pointed out as important. The lack of communication and feed-back from radiologists in the digital environment is expressed. Conclusion: To engross knowledge it is necessary to have constantly recurring personal feed-back. An electronic messenger system could be used as a supplementary tool for instant feed-back. Lacking radiologists, I recommend collegial reviews. Building a system for this will be the topic of my next paper. S262 A B C D E F G F H B-538 11:33 Radiographer-acquired and radiologist-reviewed ultrasound examination: Agreement with radiologist’s bedside evaluation C. Tapper1, L. Thorelius2, A. Knutsson1, Ö. Smedby1; 1Linköping/SE, 2Herlev/DK ([email protected]) Purpose: A growing demand for ultrasound examinations and higher quality requirements motivate searching for routines that combine the diagnostic accuracy of radiologist-performed examinations with the economical advantages of sonographer-performed examinations. One possible approach is to use strictly standardized acquisition and documentation schemes that give the radiologist access to all the relevant information after the examination. A recently introduced method (“standardized method”), combining acquisition by a radiographer, documentation as standardized cine-loops and review by a radiologist, was compared with the formerly used routine (“traditional method”), where the diagnosis is made bedside by the radiologist. Methods and Materials: In 64 polyclinic patients, the kidneys (n = 27) or the gallbladder (n = 37) was examined with both the standardized and the traditional method. The off-line review was always made by a different radiologist than the bed-side examination. The radiologist’s findings of hydronephrosis, tumours, cysts, echogenicity and cortical thickness (in the kidneys) and wall thickness, concrements and polyps (in the gallbladder) were compared between the methods with respect to agreement (proportion of agreement and kappa coefficient) as well as systematic differences (McNemar test). Results: The findings on kidney examination showed a median agreement between the two methods of 87% (70-100 %; kappa = 0.68-1.0), and those on the gallbladder examination showed an agreement of 94% (86-100%; kappa = 0.65-1.0). There were no significant systematic differences between the methods. Conclusion: The satisfactory agreement indicates that ultrasound examinations performed by a radiographer and analyzed off-line by a radiologist may be an alternative to bedside examinations by a radiologist. B-539 11:42 Balancing diagnostic image quality with entrance dose and filtration in computed radiography: An European perspective T. Lehnert, M. Kissner, R. Hammerstingl, J.O. Balzer, M.G. Mack, T.J. Vogl; Frankfurt a. Main/DE ([email protected]) Purpose: In this study, image quality was based on required clinical criteria, in order to investigate to what degree entrance dose could be lowered and what kind of added filtration can be used without impinging on radiologist confidence levels in diagnosing. Methods and Materials: Images were taken of extremities from a cadaver using stepwise decreasing dose levels and variation of added filtration (no added filtration, aluminum, aluminum/copper) under digital projection radiography (Kodak DirectView CR950). Four radiologists were presented the images in a blinded fashion and rated each with an image quality score from 1 to 9 indicated very satisfied and 1 as very unsatisfied indicating loss of diagnostic value. Dose levels (DL) considered were 100, 75, 50 and 25% of the normal and customary X-ray techniques used for the particular body part and projection. Results: Without added filtration, image quality mean score was rated with 6.3 (DL 100%), 5.5 (DL 75%), 5.1 (DL 50%) and with 4.3 (DL 25%). An added aluminum filtration induced an image quality mean score of 5.8 (DL 100%), 5.9 (DL 75%), 4.7 (DL 50%) and of 3.4 (DL 25%). Using aluminum/copper filtration, image quality mean score was rated with 5.9 (DL 100%), 5.8 (DL 75%), 4.6 (DL 50%) and with 2.9 (DL 25%). Conclusion: It is possible, in the case of extremities, to lower entrance doses up to 75% of the
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