Tracking of the left ventricle in contrast enhanced echocardiography by anisotropic filtering and active contours algorithm

Contrast agents together with second harmonic imaging improve endocardial border detection in echo images. Aim of the study was to assess whether non linear anisotropic filtering after segmentation of gradient vector flow (GVF) based active contour algorithm can be applied on contrast echo images for automatic detection of left ventricular (LV) contours. LV volumes were measured in 20 subjects by Cine Magnetic Resonance (MR) and transthoracic second harmonic echo after intravenous administration of the contrast agent Levovist. Contrast echo images were analyzed both manually and automatically; MR images were automatically analyzed. LV volumes were calculated according to Simpson's rule. A good correlation with MR volumes was found for manual LV volumes (r.93 and .92 for end diastolic and end systolic volumes, respectively, p <.05). A still good correlation was found for the automatically assessed volumes in both phases (r=.90 and .91, p <05). Thus automatic endocardial border delineation by anisotropic filtering and GVF based active contour algorithm is feasible on contrast echo images. This method may represent an approach for automatic endocardial border analysis in ultrasonic imaging.