Validation of diagnosis capabilities of a pocket echoscopic device’s for heart investigations
Nazim Alimazighi,
1
MD ,
Patricia Reant, MD
1
PhD
Marina Dijos,
1
MD ,
Amira Zaroui,
1
MD ,
Aude Mignot,
1
MD ,
Marianne Lafitte,
1
MD ,
Xavier Pillois, MD1, Raymond Roudaut, MD1, Anthony DeMaria, MD PhD2, and Stephane Lafitte, MD PhD1
1 Hopital
Cardiologique Haut-Leveque, CHU de Bordeaux, Universite Bordeaux II, CIC-0005, Bordeaux-Pessac, France; 2 University of California at San Diego (UCSD), CA, USA
INTRODUCTION
 Recently, progressive electronic and computer miniaturization has succeeded in creating an ultrasmall echocardiograph which can be fully contained in the pocket of a laboratory coat. We hypothesized that,
based on greyscale imaging and color Doppler capabilities, this new pocket ultrasound device (PUD) (Figure 1) could accurately record diagnostic findings.
Ultrasound windows quality
Left ventricular (LV) function
OBJECTIVES
 This study was designed to investigate the feasibility and comparative accuracy of this ultrasmall
device to evaluate the cardiac structure and function by ultrasound.
good
normal
average
moderate
EF>60% 35%≤EF<60%
Segmental LV function
LV morphology
LV thickness
METHODS
 A total of 100 patients referred for conventional clinical indications underwent a standard
echocardiographic examination performed by a physician specialized in echocardiography.
Subsequently, a second physician blinded to the results obtained by the first observer performed an
evaluation using the PUD (Vscan, GE Medical Systems) on the same patients. Study end-points were
echocardiographic window quality, left ventricular (LV) morphology, function, hypertrophy, right
ventricular (RV), atrial and vena caval morphologies, aortic and mitral valvular disorders, and pericardial
structure. Results were assessed using a scale consisting of 3 grades (Table 1). Concordances were
calculated using the Cohen-Kappa test.
WT<12mm
insufficient
severe dysfunction
EF<35%
normal
normal
abnormal
dilated
EDD<58mm
EDD≥58mm
normal
hypertrophy asym. hypertrophy
normal
normal
normal
normal
normal
lack
lack
normal
dilated
dilated
dilated
abnormal
abnormal
slight
slight
slight
normal
normal
dilated
dilated
Ø ≤ 25mm
Ø > 25mm
WT≥12mm
Right ventricular (RV)
Left atrium (LA)
Right atrium (RA)
Aortic valve
Mitral valve
Aortic regurgitation
Mitral regurgitation
Pericardium
effusion
Vena cava
Abdominal Aorta
moderate severe
moderate severe
moderate severe
dilated + no resp. var.
(EF: LV ejection fraction, EDD: LV end-diastolic diameter, WT: LV Wall thickness)
Table 1: List of parameters obtained in the evaluation
RESULTS
 Table 2 presents concordances between PUD and standard echocardiographic machines.
 Concordance in image quality proved good with a kappa coefficient (K) of 0.71.
 LV function and morphology were normal in 68% and 81% of cases, respectively. Concordances
between systems were excellent for these parameters (K 0.91 and 0.96). (Figure 2)
 Concordance for LV hypertrophy was good (K 0.74).
 Fifteen patients exhibited RV dilation by full feature exam, which was detected by PUD in 93% of
cases.
 Concordances for mitral regurgitation grades were 0.90, 0.95, and 1.00, respectively.
 Of our patients, 18 and 19 presented pericardial effusion when using standard and PUD and
respectively. Figure 3 depicts concordances for quantitative abdominal aorta measurements.
20
y = 0,90x + 6,04
70
r = 0,84
p<0,001
15
2
11,96
10
5
Differences
VSCAN EF
60
50
40
30
0
0
10
20
30
40
50
60
70
80
-5
-10
20
-14,06
-15
10
-20
0
0
20
40
60
80
-25
Linéaire (TTE EF = f(VSCAN EF))
50
40
Bias = -1,05
4
3,775
3
30
20
2
1
0
-1 0
10
Lim of agreement (95%)
Figure 2 : Correlation (Figure 2a) and Bland-Altman analysis (Figure 2b) between
qualitative ejection fraction (EF) obtained with conventional TTE and PUD
20
30
40
50
60
-2
10
-3
-3,042
-4
0
20
40
60
-5
Means
Aorta Diameter TTE (mm)
Means
Differences
5
y = 0,96x + 0,29
r2 = 0,94
p<0,001
0
TTE EF
TTE EF = f(VSCAN EF)
Aorta Diameter VSCAN (mm)
80
6
60
Differences
90
Figure 1 : Vscan pocket ultrasound device
TTE = f(VSCAN)
Linéaire (TTE = f(VSCAN))
Differences
Bias = 0,3663
Lim of agreement (95%)
Figure 3 : Correlation (Figure 3a) and Bland-Altman analysis (Figure 3b) between
quantitative abdominal aorta measurements obtained with conventional TTE and PUD
Table 2: Results of the concordance analysis between conventional echocardiographic evaluation
and PUD, and between the two observers using PUD. Results for each diagnostic target are
displayed with the concordance value and the Kappa coefficient parameters
CONCLUSION
 This new pocket sized ultrasound device enabled scanning examinations which showed good concordance of diagnostic capability to standard full feature echocardiographic
instruments. This study validated the smallest pocket echoscopic device VSCAN, first ultraportable TTE with 2D black and white and color Doppler mode, which is easy to use
and transport, providing accurate measurements when operated by an experienced physician who wishes to complement patient evaluation in clinical practice.