Three-dimensional automatic quantitative analysis of intravascular ultrasound images

Intravascular ultrasound (IVUS) has established itself as a useful tool for coronary assessment, The vast amount of data obtained by a single IVUS stu dy renders manual analysis impractical for clinical use, A computerized met hod is needed to accelerate the process and eliminate user-dependency. In t his study, a new algorithm is used to identify the lumen border and the med ia-adventitia border (the external elastic membrane). Setting an initial su rface on the IVUS catheter perimeter and using active contour principles, t he surface inflates until virtual force equilibrium defined by the surface geometry and image features is reached, The method extracts these features in three dimensions (3-D), Eight IVUS procedures were performed using an au tomatic pullback device. Using the ECG signal for synchronization, sets of images covering the entire studied region and corresponding to the same car diac phase were sampled. Lumen and media-adventitia border contours were tr aced manually and compared to the automatic results obtained by the suggest ed method. Linear regression results for vessel area enclosed by the lumen and media-adventitia border indicate high correlation between manual vs, au tomatic tracings (y = 1.07 x -0.38; r = 0.98; SD = 0.112 mm(2); n = 88), Th ese results indicate that the suggested algorithm may potentially provide a clinical tool for accurate lumen and plaque assessment. (C) 2000 World Fed eration for Ultrasound in Medicine & Biology.