A MULTIPLE ACTIVE CONTOUR MODEL FOR CARDIAC BOUNDARY DETECTION ON ECHOCARDIOGRAPHIC SEQUENCES

Tracing of left-ventricular epicardial and endocardial borders on echo cardiographic sequences is essential for quantification of cardiac fun ction. We designed a method based on an extension of active contour mo dels to detect both epicardial and endocardial borders on short-axis c ardiac sequences spanning the entire cardiac cycle, We validated the r esults by comparing the computer-generated boundaries to the boundarie s manually outlined by four expert observers on 44 clinical data sets, The mean boundary distance between the computer-generated boundaries and the manually outlined boundaries was 2.80 mm (sigma = 1.28 mm) for the epicardium and 3.61 (sigma = 1.68 mm) for the endocardium, These distances were comparable to interobserver distances, which had a mean of 3.79 mm (sigma = 1.53 mm) for epicardial borders and 2.67 mm (sigm a = 0.88 mm) for endocardial borders, The correlation coefficient betw een the areas enclosed by the computer-generated boundaries and the av erage manually outlined boundaries was 0.95 for epicardium and 0.91 fo r endocardium, The algorithm is fairly insensitive to the choice of th e initial curve, Thus, we have developed an effective and robust algor ithm to extract left-ventricular boundaries from echocardiographic seq uences.