Computerized evaluation of echocardiographic stress tests in patients with poorly visualized endocardium using analysis of color-encoded contrast-enhanced images.
OBJECTIVE
We hypothesized that real-time color encoding of contrast-enhanced images would allow objective detection of stress-induced wall motion abnormalities (WMA).


METHODS
We studied 117 patients with poorly visualized endocardium undergoing dobutamine stress tests. Color-encoded images (Philips, color kinesis) were obtained at rest and peak stress in four standard views during i.v. infusion of Definity. Images were reviewed without color overlays by two expert readers, who graded regional wall motion as normal or abnormal. In 101/117 patients (86%), in whom contrast enhancement allowed endocardial tracking, regional fractional area changes were calculated from the color overlays, and thresholds for calling a stress-induced WMA were optimized in a randomly selected subgroup of 34 patients (ROC analysis) to achieve maximum agreement with expert grades. This computerized detection of stress-induced WMA was then tested prospectively in the remaining 67 patients, using the expert grades as a "gold standard".


RESULTS
20/67 patients had resting WMA and 13/67 patients developed WMA at peak stress. The automated technique detected stress-induced WMA in at least one vascular territory with a sensitivity, specificity and accuracy of 0.80, 0.65 and 0.69, while the level of agreement between the two experts was 0.62, 0.91 and 0.85, respectively.


CONCLUSIONS
Analysis of color-encoded, contrast-enhanced images allows objective, accurate, automated detection of stress-induced WMA in patients with poor acoustic windows.
Mor-Avi
Victor
V
Section of Cardiology, Noninvasive Cardiac Imaging Laboratory, University of Chicago MC5084, 5841 S. Maryland Avenue, Chicago, IL 60637, USA. vmoravi@medicine.bsd.uchicago.edu
Sugeng
Lissa
L
Weiss
Robert J
RJ
Toledo
Eran
E
Weinert
Lynn
L
Bouchard
Tina
T
Spencer
Kirk T
KT
Lang
Roberto M
RM
D002316:Cardiotonic Agents; D003116:Color; D003287:Contrast Media; D004280:Dobutamine; D025401:Echocardiography, Stress; D004562:Electrocardiography; D004699:Endocardium / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005466:Fluorocarbons; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007262:Infusions, Intravenous; D012372:ROC Curve; D012680:Sensitivity and Specificity
D002316:Cardiotonic Agents; D003287:Contrast Media; D005466:Fluorocarbons; D004280:Dobutamine; C042852:perflutren