1. A method of evaluating images of a body region, wherein at least one of the images shows an abnormality indicative of a possible lesion, comprising the steps of: determining locations of pixels in each image that show such abnormality; for each of a set of intensity levels, I, determining a contour around the cluster containing the pixels at the locations determined in the step of determining; defining a function, F, that discriminates a distinct characteristic of each contour in a nested sequence; defining a function, G, used to characterize the changes in the value of the function F over the range of contours at each intensity level; and identifying a lesion as being more likely to be benign or more likely to be cancerous based on at least one threshold value for the function G or based on threshold values and locations of pixels depicting a plurality of lesions within the body region.