Analysis of left ventricular wall motion using dynamic alignment

An approach for tracking and quantifying the non-rigid, non-uniform motion of the left ventricular endocardial wall from two-dimensional ultrasound image sequences is presented. Given a set of endocardial borders, obtained automatically by Acoustic Quantification technique, an internal and floating reference system is chosen to compensate for cardiac movements not involved with contraction. The dynamic alignment approach is then applied to the contour coordinates expressed in polar form, by performing shrinking and enlarging of the angle axes of the two waveforms, to obtain the point-by-point correspondence between borders of consecutive frames. When applied to the systolic or diastolic sequence, this method yields trajectory estimates of any contour point. The systolic and diastolic displacement of 100 equally spaced fiduciary points was evaluated in a normal population (N=5, mean age±se 64±2) and compared to wall motion profiles obtained with the centerline method