Fig. 3 Images demonstrating the significant changes of technology between 1984, 1987 (CNBSS-study), and a follow-up mammogram of the same patient of 1993. Even though the later technology is still far from present contrast resolution, it becomes obvious that on the former mammograms almost no structures can be discerned in 80 % of the breast making detection of both masses and microcalcifications almost impossible. Images reproduced courtesy of Dr. Roberta Jong, Sunnybrook Health Sciences Centre, Toronto Canada