RESTORATION OF RADIAL OPTICAL FLOWS IN ECHOCARDIOGRAPHIC SEQUENCES

In this paper, we suggest a one-dimensional (scalar) approach to the method of optical flows for estimating the contracting/expanding motion in echocardiographic image sequences of the left ventricle. Provided that the method's output is a “valid” estimate of the radial velocity component, it offers, at an equivalent spatial resolution, a significant computational saving compared to the traditional method. An evaluation of the validity is carried out by comparison of the results of the two methods on the basis of a normalized mean square deviation. The one-dimensional method then seems to reproduce radial velocities similar to the ones obtained by using the traditional method.

In order to analyze the scalar velocity estimates, we can summarize them as time series representing the motion of different parts of the cardiac wall. By comparing features in the radial motion from different sectors of the left ventricle and from different heart cycles, the presented system offers a useful tool for identification and characterization of ischemia in the cardiac function.