This was repeated for all calcifications within the cluster and the calcifications were recombined into the original spatial configuration creating a normalized cluster image. Thirty-three unique normalized cluster images were generated from seven mastectomy slices in this way (several clusters were extracted from each sample). At 5 magnification , the field of view of the specimen cabinet was 1 cm 1 c m and so all clusters encompassed an area smaller than 1 c m 1 cm.