1. A non-transitory computer readable storage medium having stored thereon a computer program comprising instructions, which when executed by a computer, cause the computer to: acquire a plurality of images; identify a region-of-interest in each of the plurality of images; divide the region-of-interest into a plurality of distinct regions; locate a regional center point for each of the plurality of regions in each of the plurality of images; for each regional center point, determine a center point trajectory based on variances in position of the center points from each other in the plurality of images; decompose the center point trajectory of each regional center point into radial and circumferential components, so as to isolate radial component of the center point trajectory for each regional center point in each of the plurality of images; and based on the determined radial component for each regional center point in each of the plurality of images, display radial motion versus time curves for each regional center point.