Automated Contour Tracking For High Frame-Rate, Full-View Myocardial Elastography In Vivo

摘要

Using a retrospective ECG-gating technique, an extremely high frame rate (up to 8kHz) was previously shown achievable for full-view (12×12mm{sup}2) myocardial elastography in murine left ventricles. The purpose in this paper was to isolate the left ventricle from other structures for better displacement and strain visualization. In-vivo experiments were performed in anesthetized normal and infracted mice. After manual selection of 40-50 points in the first frame of the cine-loop (corresponding to the R-wave), the myocardial contour was automatically tracked across the entire LV and throughout the full cardiac cycle, which correctly segmented the myocardial region of interest (ROI) for better interpretation. High precision of the displacement estimation, due to high frequency (30MHz) and high frame rate (up to 8kHz) available with this system, allowed for automated tracking of a manually-initialized myocardial contour over an entire cardiac cycle. The method of manually-initialized, automated contour tracking can further enhance the capability of the elastographic technique with minimal user intervention.