Automatic tracking of local myocardial motion by correlation weighted velocity method

In this paper, we propose a new method for automatically tracking the motion of local region in left ventricular myocardium by means of ultrasonic pulsed Doppler signal. This method consists of a velocity detection procedure based on correlation weighted mean instantaneous velocity and a motion tracking procedure employing a myocardial elastic model. Most of ultrasonic pulsed Doppler signals observed in clinical diagnosis contain considerable amount of speckle noise, which causes detection error of velocity. The detection error is accumulated in the motion tracking procedure and yields obviously incorrect motion trajectory. The procedure of correlation weighted mean velocity is aimed to reduce the velocity detection error and the myocardial elastic model is used to avoid the accumulation of the error to keep track of the motion of the myocardium in reasonable accuracy. The result of evaluation test shows that this method is able to improve the accuracy of tracking approximately 40% relative to a conventional CLS approach.