Q120.
Which following statement about detector is false?
(1.) scintillation detector convert x-ray into light, and than into electrical energy
(2.) gas detector converts x-ray directly into electrical energy
(3.) ceramic is often used as scintillator in photodiode
(4.) gas detector has high detection efficiency
Q121.
Which following statement about filtered back- projection is false?
(1.) often used in modern CT
(2.) referred to as the convolution method
(3.) it combines back-projection algorithm and filter
(4.) star artifact still can be seen
Q122.
Which of the following positions has to be used for criterion between front illuminated photodiode
detector method and back illuminated photodiode detector?
(1.) The position of illuminant
(3.) The position of light diode
Q123.
When we adjust window/level, many factors should be noticed. Exclude
(1.)
(2.)
(3.)
(4.)
Q124.
wide window should be used to tissue of greatly differing attenuation within the image
wide window often used to see brain image
narrow window is good at showing tissues with similar density
level should be centered near the average attenuation of the tissue of interest
4D image can be created in volume rendering technology of CT field. What is the fourth dimension?
(1.) length
Q125.
(2.) time
(3.) opacity
(4.) brightness
Which following statement about MTF (modulation transfer function)is true?
(1.)
(2.)
(3.)
(4.)
Q126.
(2.) The position of wire
(4.) The position of switching array
MTF=0 means the imaging system has produced the object exactly
MTF=1 indicates no transfer of object to image
MTF describe contrast resolution
MTF describe spatial resolution
Which is not the characteristic of HRCT?
(1.) can be applied any part of body
(3.) high spatial frequency algorithm
(2.) narrow beam collimation
(4.) small pixel size
Q127.
Which artifact don’t we usually see in modern CT scanner?
(1.) motion artifact
(2.) rings and band artifact
(3.) streak artifact
(4.) shading artifact
Q128.
Which statement is wrong about interpolation mathematical technique?
(1.) get some unknown value
(2.) usually use linear interpolation in CT
(3.) currently 360-degree linear interpolation algorithm is mostly used
(4.) currently 180-degree linear interpolation algorithm is mostly used
Q129.
If mAs per rotation is 100, pitch is 1.5. What are the effective mAs and CTDIvol?
(1.) 67, 0.67
Q130.
(2.) 200, 2
(2.) mA meter
(4.) magnetic plate
Which of the following is an incorrect multi slice CT?
(1.)
(2.)
(3.)
(4.)
Q133.
(2.) FOV
(4.) reconstruction algorithm
Which of the following factors is used to adjust contrast of CT images?
(1.) kVp meter
(3.) window width & level
Q132.
(4.) 200, 0.67
Which one doesn’t affect the longitudinal ( z-axis) resolution?
(1.) detector size
(3.) reconstruction interval
Q131.
(3.) 67, 2
It is possible to get several tomography same time.
It is possible to get isotropic images.
Cone beam X-ray is used.
The thickness of images is determined by FOV.
Which of the following is an incorrect CT detector?
(1.) The detector has the scintillation type and the gas type.
(2.) The curve linear detector has the better uniformity concerning the length of ray than the Linear
detector.
(3.) The scintillation type is better than the gas type for effectiveness of detection.
(4.) The gas detector has no way to reduce scattered rays.
Q134.
Which of the following explanations is a correct spatial resolution?
(1.) PSF (point spread function)
(3.) CTF (contrast transfer function)
(2.) LSF (line spread function)
(4.) (D) MTF (modulation transfer function)
Q135.
Which of the following explanations concerning direct oil cooling method of CT tube is incorrect?
(1.) It is contacted with insulating oil directly from outside of tube.
(2.) It is circulated by air from outside of tube.
(3.) The anode is directly contacted with insulating oil.
(4.) The cathode is directly contacted with insulating oil.
Q136.
Which of the following image processing is needed to convert collected measurement data from DAS to
raw data?
(1.) pre-processing
(3.) back projection
Q137.
(2.) convolution
(4.) post-processing
Which of the following factors can affect Z-axis geometric dose efficiency of MDCT based on the cone
beam geometry?
(1.) To minimize focal spot
(3.) The breadth of the fan beam
Q138.
Which of the following problems could occur when CT guided lung biopsy is conducted?
(1.) Lung metastasis
(3.) Pneumothorax
Q139.
(2.) 0.4%
(2.) kernel
(3.) algorithm
(4.) slip ring
(2.) effective resolution
(4.) spatial resolution
The principal reason to use high kVp during CT examination is…
(1.) fewer artifacts
(3.) improved spatial resolution
Q143.
(4.) 4%
Which of the following is increased with increasing spiral CT pitch?
(1.) axial resolution
(3.) contrast resolution
Q142.
(3.) 1%
For spiral CT, the high- voltage cable and signal cable are replaced by?
(1.) DAS
Q141.
(2.) Pleural effusion
(4.) Pneumonia
What is the subject contrast of white matter and gray matter when white matter has 42 HU and gray
matter has 46 HU in CT images?
(1.) 0.1%
Q140.
(2.) beam collimation
(4.) The number of detector cell
(2.) reduced scan time
(4.) reduced patient dose
A 40cm field of view is imaged using a 512 matrix and 10mm slice thickness, what is the approximate
voxel size ?
(1.) 4.2mm3
(2.) 5.8mm3
(3.) 7.8mm3
(4.) 10mm3
Q144.
A multislice CT image is obtained at 120kVp, 200mA, 2sec. the resulting anode heat load is
approximately ?
(1.) 500kHU
Q145.
(3.) 700Khu
(4.) 850kHU
What is the structure of the section marked with an arrow?
(1.) internal carotid artery
(3.) middle cerebral artery
Q146.
(2.) 650kHU
(2.) basilar artery
(4.) vertebral artery
These are the images of temporal bone CT. Which of the following explanations of examination method
& image display is correct?
(1.)
(2.)
(3.)
(4.)
bone algorithm, 1-2mm slice thickness, wide window width
standard algorithm, 3-5mm slice thickness, narrow window width
standard algorithm, 3-5mm slice thickness, wide window width
bone algorithm, 1-2mm slice thickness, narrow window width
Q147.
Choose the answer that point vertebral artery correctly.
(1.) A
Q148.
(2.) B
(3.) C
(4.) D
What is the structure of the section marked with an arrow?
(1.) INCUS
(3.) MASTOID AIR CELL
(2.) COCHLEA
(4.) INTERNAL ACOUSTIC CANAL
Q149.
What is the correct name of artifact marked with an arrow?
(1.) Edge gradient artifact
(3.) High contrast foreign body artifact
Q150.
(2.) Motion artifact
(4.) Aliasing artifact
What is incorrect explanation of images below?
mean: -106.21
max: -50
min: -250
stddev: 31.92
(1.)
(2.)
(3.)
(4.)
The study is implemented to measure amount of intra abdominal fat.
The HU of fat is +50.
The threshold of abdominal area is set up -50HU from -250HU.
Select wide display FOV including soft tissue surrounded the abdominal area, and scan with about
Q151.
Choose the correct combination of name and disease ?
(1.) Aorta - aneurysm
(3.) Pulmonary artery - embolism
Q152.
(2.) Aorta - embolism
(4.) Pulmonary vein - embolism
Choose the correct combination of 2nd and 4th enhancing order when ante-cubital vein contrast has
injected?
(1.) ① ②
(2.) ③ ④
(3.) ① ④
(4.) ② ③
Q153.
Which of the following explanations is incorrect?
(1.)
(2.)
(3.)
(4.)
Q154.
Which of the following explanations of disease that could guess from the image below is incorrect?
(1.)
(2.)
(3.)
(4.)
Q155.
This study is for intervention of HCC patient.
Insert catheter into SMA and RHA.
HA is shown at image B.
The name of this study is lipiodol CT.
The organ indicated by arrow is gall bladder.
Acute cholecystitis symptom is accompanied.
Emergent surgery is needed.
This is contrast enhancing image of venous phase.
Which of the following statements is optimal for pelvis CT to examine bladder?
(1.)
(2.)
(3.)
(4.)
To
To
To
To
examine
examine
examine
examine
the
the
the
the
bladder
bladder
bladder
bladder
fully
after
fully
after
filled with urine
voiding of urine
filled with contrast
removing urine by catheter insertion
Q156.
Which of the following positions is appropriate for the suspected patient who has fracture of shoulder
and scapula in CT scan?
(1.) supine position with pronated both arms.
(2.) supine position with supinated both arms.
(3.) supine position with raised both arms.
(4.) supine position with bended both arms.
Q157.
What is the passage of injected contrast in myelography CT?
(1.) subdural space
(2.) epidual space
(3.) subarachnoid space
(4.) spinal cord
Q158.
This is the result of measured left ventricle’s function in phase of rest by using CT cardiac angiography.
Choose the best answer which can not aware directly from the image below?
(1.)
(2.)
(3.)
(4.)
Ejection Fraction
End Diastolic Volume
End Systolic Volume
coronary artery anatomy
Q159.
This is the image of ECG-gating cardiac CT that has been expended its limitation of application by
developing technology of MDCT. Which of following statements is incorrect with examination of
cardiac CT by ECT-gating?
(1.) For examination of the patient who has acute chest pain in emergency room
(2.) For pulmonary embolism W/U of the patient who has dyspnea symptom after operation
(3.) For W/U about embolism source of the patient who has cerebral infarction
(4.) For W/U about the mass which is found out in the lung
Q160.
Which of the following combinations is not appropriate?
(1.) 1st generation – Pencil beam
(3.) 3rd generation – Nutate-rotate (N-R)
Q161.
(2.) 2nd generation – Translate-rotate (T-R)
(4.) 3rd generation – Multislice CT
Which of the following statements is incorrect?
(1.) Single slice CT has a detector array only on the slice plane axis.
(2.) With multislice CT, multiple images are obtained with a single rotation.
(3.) With multislice CT, detectors with superior X-ray dose efficiency are required.
(4.) The detectors of multislice CT are exclusively asymmetric matrix.
Q162.
Which of the following statements is incorrect?
(1.) The number of cone-angle artifacts with multislice CT is high compared to single slice CT.
(2.) The number of partial volume artifacts with multislice CT is high compared to single slice CT.
(3.) Multislice CT allows shorter imaging times than with single slice CT.
(4.) Multislice CT allows wider imaging than with single slice CT.
Q163.
Which of the following is related to Multi slice CT?
a. Pencil beam
(1.) a, b, c
b. Cone beam
(2.) a, c
c. Water bath
(3.) b, d
d. DAS
(4.) a, b, c, d
Q164.
Which of the following correctly illustrates the diagram below?
(1.) Single array detector
(3.) Fixed array detector
Q165.
(2.) Matrix detector
(4.) Hybrid detector
Which of the following is the main cause of cone beam distortion in MDCT equipment?
(1.) Magnify of fan beam
(2.) Decreas of con beam width
(3.) The reduction of both the number of detector and the detection efficacy of decrease
(4.) X-ray forcus and detector row is not vertical to the axis
Q166.
Which of the following combinations is not appropriate?
(1.) Cathode – Tungsten
(2.) Characteristic X-ray – Anode target substance
(3.) Continuous X-ray – Beam hardening
(4.) Compton scattering – Knocked-on atom
Q167.
Which of the following combinations is not appropriate?
(1.)
(2.)
(3.)
(4.)
Q168.
Slip ring – Power supply
DAS – Fixed part of the gantry
X-ray tube – Rotating part of the gantry
Bow-tie filter – Elimination of scattered radiation
Which characteristic is not appropriate for a high-voltage generator?
(1.) The
(2.) The
(3.) The
(4.) The
Q169.
tube
tube
tube
tube
voltage
voltage
voltage
current
ripple should be sufficiently high.
waveform rise and fall time should be sufficiently short.
should be stable.
should be stable.
Heat units for a constant-potential x-ray tube are given by:
(1.) kVp x mAs.
(3.) 1.4 x kVp x mAs.
(2.) Joules/1.4.
(4.) Joules x 1.4.
Q170.
Which of the following is not related to collimator?
(1.) Slice thickness
(3.) Radiation dose
Q171.
(2.) Detection ability of the detector
(4.) Transmission width of the X-ray
Which of the following statements is incorrect?
(1.) The CT number is a comparative value where water is 0 and air is -1000.
(2.) Reducing the width of the window improves the contrast.
(3.) Reducing the width of the window makes it easier to observe bone and lung fields.
(4.) Raising the window level makes the image density darker.
Q172.
If the linear attenuation coefficient of a certain substance is twice the linear attenuation coefficient of
water, which of the following substances is the closest?
(1.) Air
Q173.
(2.) 512 mm
(4.) 100 mm
(2.) kV
(4.) atomic number
(2.) bladder
(3.) spleen
(4.) fat
In chest CT , what is the window level (HU) in lung window?
(1.) 100
Q177.
(3.) 320 mm
What the highest CT number (no contrast medium)?
(1.) liver
Q176.
(4.) Bone
What the factor to calculate the CT number?
(1.) linear attenuation coefficient
(3.) mAs
Q175.
(3.) Muscle
When pixel size is 0.5 mm and the matrix is 512, how big is the FOV generally?
(1.) 256 mm
Q174.
(2.) Fat
(2.) 40
(3.) -100
(4.) -400
Which of the following combinations is not appropriate?
(1.) Sinogram vertical axis – View
(2.) Projection – Inverse Radon transform
(3.) Aliasing – Low sampling frequency
(4.) Linear attenuation coefficient – Density of the substance
Q178.
The revision of offset & calibration file, logarithm processes and the standardization are performed at
which stage?
(1.) pre-processing
(3.) back projection
(2.) post-processing
(4.) convolution
Q179.
The x-ray beam is heavily filtered in CT scanners to:
(1.) Increase the x-ray output.
(3.) Improve spatial resolution.
Q180.
What causes the "Cupping" artifact on a CT image?
(1.) Decline of linearity
(2.) Decline of contrast resolution
(4.) An error of reconstruction Algorithm
(3.) Decline of uniformity
Q181.
Choose the most important feature which must be implied in order to obtain a heart image with the
minimal motion.
(1.) High voltage of over 150kV
(3.) Low voltage of under 50mA
Q182.
(2.) ECG gating
(4.) Used axial scan mode
What is the patient motion artifacts?
(1.) streaks
Q183.
(2.) Reduce the beam-hardening artifact.
(4.) Improve low-contrast resolution.
(2.) shading
(3.) rings
(4.) bands
Which of the following combinations is not appropriate?
(1.) Segment reconstruction – Multiple heartbeats
(2.) Number of segments – Heart rate
(3.) ECG dose modulation – Exposure reduction
(4.) Prospective ECG-gated scanning – High heart rate
Q184.
Which of the following statements about CT-AEC is incorrect?
(1.) With patient size AEC, the X-ray dose can be controlled based on the difference in X-ray
absorption according to the size of the subject.
(2.) With Z-axis AEC, the X-ray dose is controlled by analyzing the anatomy of the subject along the
body axis with a scanogram.
(3.) 3D dose modulation includes a method in which X-ray output is modulated with each 1/4 rotation
of the X-ray tube.
(4.) With CT-AEC, setting the standard deviation is required for the equipment of all manufacturers.
Q185.
Which of the following is an incorrect statement of the dose reduction effectiveness by dose modulation?
(1.) Decrease dose by low voltage
(3.) Decrease dose by Z-axis of patient
Q186.
Which of the following combinations is not appropriate?
(1.) BHC – Head
(2.) Quantum denoising filter – Smoothing filter
(3.) Streak artifact – Pelvic region
(4.) Cupping artifact – Beam hardening correction
(2.) Decrease dose at cadio systolic
(4.) Decrease dose by patient diameter
Q187.
Which of the following is not shown on the image below?
(1.) Cerebellum
th
(3.) 4 ventricle
Q188.
(2.) Lateral ventricle
(4.) Petrous bone
Select the correct CT number on the section marked ‘A’ on the image below.
(1.) About 200 ~ 250
(3.) About -80 ~ -90
(2.) About 0 ~ 20
(4.) About -500 ~ -600
Q189.
Below is a three dimension image of intracranial blood vessel. Name the section marked with ‘A’.
(1.) Vertebral artery
(3.) Anterior cerebral artery
Q190.
(2.) Middle cerebral artery
(4.) Basilar artery
Choose the correct answer for the sections marked ‘A’ and ‘B’.
a
b
(1.) a: cochlea
b: auditory ossicles
(3.) a: auditory ossicles
b: vestibule
(2.) a: cochlea
b: vestibule
(4.) a: auditory ossicles b: cochlea
Q191.
Which of the following is not shown on the PNS image?
(1.) Frontal sinus
(3.) Inferior concha
Q192.
What disease is illustrated in the anatomical structure on the image below?
(1.) Aorta - aneurysm
(3.) Pulmonary artery – embolism
Q193.
(2.) Maxillary sinus
(4.) Nasal septum
(2.) Aorta - embolism
(4.) Pulmonary vein - embolism
Which of the following is the correct explanation of the pathway of contrast media which has injected on
the pedal?
(1.) IVC - Rt.atrium - Rt.ventricle - Pulmonary vein - pulmonary artery - Lt. atrium - Lt. ventricle Aorta
(2.) IVC - Rt.atrium - Rt.ventricle - Pulmonary artery - pulmonary vein - Lt. atrium - Lt. ventricle Aorta
(3.) SVC - Rt.atrium - Rt.ventricle - Pulmonary artery - pulmonary vein - Lt. atrium - Lt. ventricle Aorta
(4.) SVC - Rt.atrium - Rt.ventricle - Pulmonary vein - pulmonary artery - Lt. atrium - Lt. ventricle Aorta
Q194.
Which of the following in an incorrect statement on the chest structure?
(1.) Rt lung – 3 lobes – 10 segment
(2.) Lt lung – 2 lobes – 8 segment
(3.) Rt lung – major fissure – minor fissure
(4.) Lt lung – major fissure – minor fissure
Q195.
Which of the following is an incorrect explanation of the pathway from big to small?
(1.) Aorta
– Artery - Arteriole
(2.) Venacava – Vein - Venule
(3.) Trachea – Bronchi - Bronchioles
(4.) Trachea – Bronchioles - Bronchi
Q196.
Which of the following is enhanced last on the image below?
(1.) ①
(2.) ②
(3.) ③
(4.) ④
.
Q197.
Choose the incorrect statement for the image below.
(1.)
(2.)
(3.)
(4.)
It was scanned to evaluate the fat in the abdomen.
It was scanned with high resolution.
The threshold of abdomen was adjusted between -250HU and -50HU.
The 10mm of slice thickness and large FOV were used to display whole soft tissues around
abdomen.
Q198.
Which of the following correctly names the section marked with an arrow?
a. A-urinary bladder
b. B-prostate gland
c. B-seminal vesicle.
d. C-rectum
(1.) a, b
Q199.
(2.) b, c
(3.) c, d
Which of the following is suspected on the image below?
(1.) Cholecystitis
(3.) Renal cell carcinoma
(2.) Pyelonephrosis
(4.) Pancreatitis
(4.) a, b, d
Q200.
Where is the fracture shown on the image below?
(1.) Cuboid
Q201.
(3.) Calcaneus
(4.) Talus
(3.) Trapezium
(4.) Trapezoid
Where is the fracture shown on the image below?
(1.) Scaphoid
Q202.
(2.) Navicular
(2.) Capitate
What is the structure of the section marked with an arrow?
(1.) C1(atlas)
(2.) C2(axis)
(3.) C4
(4.) C6
Q203.
Name the anatomical structure indicated by the arrow.
(1.) Inferior Vena Cava Filter
(3.) Graft
Q204.
(2.) Gelform
(4.) Balloon catheter
Which of the following explanations of CT-AP and CT-HA is not appropriate?
(1.) CT-AP is a portography method where a contrast agent is introduced from the superior mesenteric
artery or other vessel.
(2.) Hepatic cysts are not densely stained with either CT-AP or CT-HA.
(3.) It is necessary to use more contrast agent with CT-HA than with CT-AP.
(4.) Classic hepatocellular carcinoma is more densely stained with CT-HA.
Q205.
Which of the following explanations of a head examination is not appropriate?
(1.) In order to obtain sufficient contrast in the brain substance, it is desirable to set conditions such that
the standard deviation of the image is from 3 to 5.
(2.) Beam hardening and partial volume effects are typical problems.
(3.) Epidural hematoma shows a high absorption crescent shape.
(4.) The thalamus is a favored site for hypertensive intracerebral hemorrhage.
Q206.
Which of the following explanations of TDC is not appropriate (other factors being the same)?
(1.) The
(2.) The
(3.) The
(4.) The
heavier the body weight, the
heavier the body weight, the
faster the speed of injection,
faster the speed of injection,
lower the peak CT number.
longer the time until a peak forms.
the higher the peak CT number.
the shorter the peak is maintained.
Q207.
What disease is shown in image No.1 in the supplement (simple, arterial phase, portal phase, balance
phase)?
(1.) Hepatic hemangioma
(3.) Hepatic cyst
Q208.
What is the factor does not use in perfusion CT?
(1.) MTT
Q209.
(2.) Hepatocellular carcinoma
(4.) Hepatic abscess
(2.) CVB
(3.) CVF
(4.) CVT
Which of the following statements concerning the relationship between the viscosity and osmotic
pressure of contrast agents is incorrect?
(1.) The viscosity of nonionic monomers is greater than that of nonionic dimers.
(2.) The viscosity of nonionic dimers is greater than that of ionic monomers.
(3.) The osmotic pressure of nonionic monomers is less than that of ionic monomers.
(4.) The osmotic pressure of nonionic dimers is less than that of nonionic monomers.
Q210.
Which of the following is not appropriate as a high-risk factor in adverse reactions to contrast agent?
(1.) Sex
(3.) Asthma
Q211.
Which of the following response is not appropriate if the agent leaks from the blood vessel?
(1.)
(2.)
(3.)
(4.)
Q212.
If the agent is being injected, stop injection immediately.
Administer antihistamine medication according to the amount leaked.
If the amount of leakage is small and not a problem, find a new route and resume injection.
If compartment syndrome is suspected, consult a specialized physician.
Which of the following is an incorrect statement of the vital sign?
(1.)
(2.)
(3.)
(4.)
Q213.
(2.) Heart disease
(4.) Allergic reaction to contrast agent
The beating of the pulse in adult is 60~80/min
There are body temperature, breath, blood pressure, and the beating of the pulse
A normal systolic blood pressure in adult is 110-140mmHg
A hypertensive diastolic blood pressure is 60mmHg..
When urticaria appears after the iodine contrast media is injected, what medicine is prepared?
(1.) Pain killer
(3.) Anti-inflammatory gent
(2.) Antihistamines
(4.) Anti-biotics
Q214.
Which of the following statements is incorrect?
(1.) Increasing the tube voltage reduces image noise.
(2.) Increasing the tube voltage reduces the difference in linear attenuation coefficient (µ).
(3.) Beam hardening is due to the fact that CT is a continuous X-ray.
(4.) Increasing the tube voltage improves the spatial resolution.
Q215.
Which of the following statements is incorrect?
(1.) Increasing the tube current increases the number of X-ray photons.
(2.) Increasing the tube current reduces image noise.
(3.) Increasing the tube current improves the spatial resolution.
(4.) Increasing the tube current improves low contrast resolution.
Q216.
Which of the following statements is incorrect?
(1.) Using thin slices mitigates the partial volume effect.
(2.) Using thin slices mitigates results in improved low contrast resolution.
(3.) Using thin slices mitigates dark band artifacts at the back of the skull.
(4.) Using thin slices improves the spatial resolution along the body axis (Z axis).
Q217.
Which of the following statements concerning helical scans with single slice CT is incorrect?
(1.) The sensitivity distribution along the body axis takes on a rectangular shape.
(2.) The greater the pitch factor, the thicker the effective slice.
(3.) Increasing the pitch factor has no effect on image noise.
(4.) Resolution along the body axis differs with 360° interpolation reconstruction and 180° opposed
beam interpolation.
Q218.
Which of the following statements concerning multislice CT is incorrect?
(1.) Increasing the number of detector arrays increases the effect of cone angle.
(2.) The smaller the smallest element of the collected slice, the worse the X-ray dose efficiency.
(3.) For image reconstruction, two-dimensional filtered backprojection (2D-FBP) is used irrespective of
the number of detector arrays.
(4.) After scanning, the thickness of each image slice can be changed.
Q219.
Which of the following statements is incorrect?
(1.) The reconstruction factor is a frequency filter for mitigating blurring during back propagation.
(2.) The high frequency accentuation factor improves low contrast resolution.
(3.) The high frequency accentuation factor improves spatial resolution.
(4.) A wide window is used to observe images using a high frequency accentuation factor.
Q220.
Which of the following statements is incorrect?
(1.) It is possible to identify the location where artifacts resulting from data collection abnormalities
occur from the shape of the artifact and the sinogram.
(2.) Cupping and capping artifacts are streak-shaped artifacts.
(3.) Windmill artifacts are specific to helical scans.
(4.) Artifacts due to the effects of cone angle are specific to multislice CT.
Q221.
Which of the following explanations concerning low contrast resolution is incorrect?
(1.) The greater the quantum number of the X-ray, the better.
(2.) The greater the electrical noise and system noise, the lower it is.
(3.) It is not affected by the reconstruction factor.
(4.) CNR is one method of evaluating low contrast resolution.
Q222.
Which of the following explanations concerning spatial resolution is incorrect?
(1.) The greater the focus size of the X-ray tube, the better.
(2.) It is affected by the ratio between the focus of the X-ray tube, the focus center distance, and the
distance between detectors.
(3.) Increasing the number of views improves the spatial resolution.
(4.) High resolution is obtained with offset reconstruction.
Q223.
A tube with a small focal spot:
(1.)
(2.)
(3.)
(4.)
Q224.
Can use a higher kVp.
Decreases the heat-loading capability of the tube.
Improves low-contrast resolution.
Improves beam-hardening artifact.
The spatial resolution of a CT scanner is affected by all of the following except:
(1.) Detector-to-detector spacing.
(3.) The scanner cycle time.
Q225.
(2.) The display matrix size.
(4.) The x-ray tube focal spot size.
Which of the following statement is correct?
(1.)
(2.)
(3.)
(4.)
if
if
if
if
the
the
the
the
width
width
width
width
of the
of the
of the
of the
pixel
pixel
pixel
pixel
increase, the
increase ,the
increase, the
increase, the
noise
noise
noise
noise
decrease, but spatial resolution
increase ,but spatial resolution
increase ,but spatial resolution
increase, but spatial resolution
decreases
decreases
decrease
increase.
Q226.
Which of the following statement is correct?
(1.) the noise increase with the dose increase
(2.) the noise increase with the inverse square root of the dose
(3.) the noise decrease with the inverse square root of the dose
(4.) the noise increase with the dose decrease
Q227.
What is the most commonly used descriptor of spatial resolution?
(1.) point spread function
(3.) contrast transfer function
Q228.
(2.) line spread function
(4.) modulation transfer function
Which of the following is the correct explanation of using the small focal spot?
a. Increase the spatial resolution
b. Decrease patient’s radiation dose
c. Decrease the sharpness
d. Increase X-ray out-put
Q229.
(1.) a
(2.) a, b
(3.) a, b, c
(4.) a, b, c, d
Which of the following is/are the correct factor/s that affects the z-axis geometric dose efficiency of
MDCT based on cone beam geometry?
a. The size of focal spot
b. beam collimation
c. The width of fan beam
d. The number of detector cell
(1.) a
Q230.
(2.) a, b
(3.) a, b, c
Which of the following is measured on the image below?
(1.) High contrast resolution
(3.) Noise
(2.) Low contrast resolution
(4.) Linearity
(4.) a, b, c, d
Q231.
Which of the following statements is incorrect?
(1.) Carcinogenesis is the main concern in terms of the probabilistic effects of CT radiation exposure.
(2.) With CTDI100, if the evaluated slice is thick (X-ray beam width), there is a concern that the dose
may be underestimated.
(3.) Indices for the dose shown on CT equipment include CTDIvol, DLP, and dose efficiency.
(4.) ECG dose modulation is a function for optimizing image quality and exposure based on body size.
Q232.
In CT, to measurement the radiation dose, what is the easiest and probably the most accurate?
(1.) CTDI
Q233.
(3.) TLD
(4.) CTRH
(3.) mSv
(4.) rad
What is the SI unit of an effective dose?
(1.) mR
Q234.
(2.) MSAD
(2.) mGy
Which of the following is an incorrect statement on the CT dose unit?
(1.) CT dose index (CTDI) is measured with pencil type ionchamber.
(2.) CTDIW is the concept of average dose that are collected both 2/3CTDIW of center part and
1/3CTDIW of surrounding part.
(3.) In conventional CT scan, CTDIVOL is CTDIW multiply packing factor.
(4.) Dose length product(DLP) is CTDIvol multiply scanned distance and unit is mGy.cm
Q235.
Name the phantom used for dose calculation by the Monte Carlo simulation.
(1.) Acryl phantom
(3.) Hermaphrodite phantom
Q236.
(2.) Anthropomorphic phantom
(4.) Water phantom
Which of the following is an incorrect statement on the effective dose?
(1.) It is a weighting factor to tissue and organ considering probability influence of biological
dimension
(2.) It is a unit for the dose evaluation of CT equipment
(3.) It is an index to reflect the radiation dangerous
(4.) It is the amount of absorbed average energy (J/kg) per unit mass
Q237.
Which of the following combinations is not appropriate?
(1.) MWM – Patient information
(2.) Dual injector – Saline flush
(3.) Workstation – Server processing system
(4.) Liquid crystal display – Phosphor
Q238.
What is the volume rendering method that express the whole volume information not surface of structure
that one voxel has many density values.
(1.) MIP
Q239.
(2.) Min IP
(3.) VRT
(4.) SSD
Which of the following enables the observation of the internal organs in the CT virtual endoscope?
(1.) Perspective drawing
(3.) Fly around
(2.) Fly through
(4.) Non-perspective drawing