Comparing Mammogram Pairs for the Detection of Lesions

We present an approach to detecting masses in temporal and bilateral (left-right) pairs of mammograms. Masses typically appear in a mammogram as well-defined, relatively bright regions. The converse is not true; by no means all relatively bright, circumscribed regions correspond to masses. Common to our approach to matching temporal and bilateral mammogram pairs is a representation of the nested structure of “salient” bright regions in a mammogram. The representation is described in Sections 2 and 3. In the case of temporal pairs, “salient” regions are extracted independently in two mammograms of the same breast, nominally the same view at two different times. Those that either appear in the later mammogram but not in the earlier one, or which have changed significantly between the two mammograms we seek to highlight. Similarly, in the case of matching bilateral pairs, salient regions that appear in only one of same-view left and right breast mammograms of the same patient, taken at approximately the same time we seek to highlight. A fuller version of this article appears as Chapter 13 of [4].