Figure 6. 4 years of patient mammograms registered using the techniques described in [9]. At year 4, three clusters of calcifications are visible in both the cranial-caudal (top row) and medial-lateral oblique (bottom row) mammograms. Comparing the location of cluster "1" to the surgical excision area (circled regions in the mammograms of year 2) suggests calcification due to surgical scarring rather than malignancy.