Estimating epicardial dynamics from the motion of coronary high curvature segments and bifurcation point regions in cineangiography

Several years ago, Y. Kong et al. (Am. J. Cardiology, vol. 27, p. 529-37, 1971) have shown that the motion of coronary bifurcations closely follows the underlying epicardial motion and therefore could be clinically used as landmarks to study cardiac contraction abnormalities. Here the authors introduce a method that uses single plane cineangiograms to compute this motion, by tracking landmark segments such as bifurcations and high curvature regions. For each pair of successive frames in the sequence, optical flow is used to provide a first estimate of the segment displacement; this is then refined through a local crosscorrelation. The segment position is then updated and the process is repeated for the next image pair in the sequence. This provides sets of translation vectors, i.e. motion fields, which are used to infer the local biaxial contraction patterns. Validation is conducted through a computer model of coronary tree in motion. Results on clinical data are also presented