Movement analysis of atheromatous carotid plaque in ultrasonic image sequence

In this investigation, motion analysis is carried out on an ultrasonic image sequence of atheromatous carotid plaque using the block matching algorithm. Each image is partitioned into a number of fixed size blocks. Fractal dimension is then estimated in each block of the current frame and used as the feature parameter. The position of the corresponding block in the previous frame of the image sequence is identified based on the similarity of that parameter. A novel Two-Pass searching scheme is employed to look for the best matching block. Fractal dimension has the advantage of relatively invariant to changes in scale and intensity. Also, it demands much lesser computation time than other conventional statistical parameters. The algorithm has been used to track the movement of a carotid plaque being captured in an ultrasonic image sequence. Its performance is compared with the results obtained in a previous study.