1. A method of detecting abnormal regions in living tissue depicted in a radiograph, the method comprising: (A) digitizing the radiograph to produce a digitized radiograph; and, by computer, (B) modifying the distribution of the digital values in the digitized radiograph; (C) identifying any suspected abnormal regions depicted in the modified digitized radiograph; (D) repeating the modifying and the identifying a fixed number of times; and then (E) making a determination as to whether each suspected abnormal region is an actual abnormal region using the results obtained in steps (B)-(D).