An Approach for registration method to find corresponding mass lesions in temporal mammogram pairs

Radiologists generally use multiple mammographic views to detect and characterize suspicious regions. When radiologists discover a suspicious lesion in one view, they try to find a corresponding lesion in the other views. Views from different projections, typically cranio caudal (CC) and medio lateral oblique (MLO) views, allow for a better realization of the lesion. Most current computer aided detection (CAD) systems differ considerably from radiologists in the way they use multiple views. These systems do not combine information from available views but instead analyse each view separately. Given the positive effect of multiview systems on radiologists' performance we expect that fusion of information from different views will improve CAD systems as well. Such multi-view CAD programs require regional registration methods to find corresponding regions in all available views. In this paper we concentrate on developing such a method for corresponding mass lesions in prior and In other words, starting from a current image containing a mass lesion, the method aims at locating the same mass lesion in the prior image. The method was tested on a set of 412 cancer cases. In each case a malignant mass, architectural distortion or asymmetry was annotated. In 92% of these cases the candidate mass detections by CAD included the cancer regions in both views. It was found that in 82% of the cases a correct link between the true. Positive regions in both views could be established by our method.