Radiology, Vol 198, 661-663, Copyright © 1996 by Radiological Society of North America
Normal mammograms and the practice of obtaining previous mammograms: usefulness and costs
TE Wilson, VK Nijhawan and MA Helvie
Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109-0326, USA.
PURPOSE: To determine the usefulness and cost of acquiring and comparing
mammograms previously obtained at a different facility with normal
mammograms. MATERIALS AND METHODS: Comparison mammographic reports obtained
within 52 months in 1,297 consecutive women (aged 33- 82 years; mean age,
53 years) were retrospectively reviewed. Mammograms in which a normal
interpretation was altered after comparison were reviewed. The clinical
importance and the cost of obtaining previous mammograms were determined.
RESULTS: Initially, interpretation was normal in 756 (58%) comparison
mammograms and abnormal in 541 (42%). Of the 756 normal mammograms, 197
(26%) were not compared with previous mammograms. Of the remaining 559, 551
(98%) had no change. In eight of the 559 (1%), the original interpretation
was altered. Seven of these eight mammograms were available for review: In
one, a developing density was detected; in three, differences were
attributable to technique; and in three, radiologists had different
interpretations. No malignancies were detected. The average labor and
postage cost was $21.49. CONCLUSION: Considering the cost and low
diagnostic yield, obtaining previous mammograms is of limited usefulness.
