Automatic Alignment of Standard Views in 3D Echocardiograms Using Real-time Tracking

In this paper, we present an automatic approach for alignment of standard apical and short-axis slices, and correcting them for out-of-plane motion in 3D echocardiography. This is enabled by using real-time Kalman tracking to perform automatic left ventricle segmentation using a coupled deformable model, consisting of a left ventricle model, as well as structures for the right ventricle and left ventricle out ow tract. Landmark points from the segmented model are then used to generate standard apical and short-axis slices. The slices are automatically updated after tracking in each frame to correct for out-of-plane motion caused by longitudinal shortening of the left ventricle. Results from a dataset of 35 recordings demonstrate the potential for automating apical slice initialization and dynamic short-axis slices. Apical 4-chamber, 2-chamber and long-axis slices are generated based on an assumption of xed angle between the slices, and short-axis slices are generated so that they follow the same myocardial tissue over the entire cardiac cycle. The error compared to manual annotation was 8.4 ± 3.5 mm for apex, 3.6 ± 1.8 mm for mitral valve and 8.4 ± 7.4◦ for apical 4-chamber view. The high computational e ciency and automatic behavior of the method enables it to operate in real-time, potentially during image acquisition.