Fig. 1.

Cross-sectional images of 3D TEE image volumes at diastole (left and center) and systole (right), illustrating the challenges specific to mitral leaflet segmentation. The yellow arrows point toward points on the annulus, showing that there is no image-based boundary between the mitral leaflets and adjacent tissue to which the leaflets are attached. The green arrows point towards the posterior leaflet at diastole, which is often pressed against the ventricular wall and is characterized by signal dropout. The pink arrow points to the coaptation zone of the leaflets at systole, showing there is no intensity-based demarcation between the anterior and posterior leaflets. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)