Optimal reference mammography: a comparison of mammograms obtained 1 and 2 years before the present examination.
OBJECTIVE
We assessed and compared the benefit of using images acquired 1 year or 2 years previously during mammography interpretations.


METHODS
Eleven radiologists and one resident reviewed 128 cases three times: once without prior mammograms for comparison, once with mammograms from the most recent (1 year) examination, and once with mammograms acquired 2 years previously. They were asked to determine whether the patient should be recalled for additional procedures. Performances under the three conditions were compared.


RESULTS
Radiologists were significantly more accurate (p < 0.001) when comparison mammograms (obtained 1 or 2 years previously) were available. Although sensitivity was not significantly affected between the availability of mammograms from 1 or 2 years earlier (p > 0.10), the specificity was. Specificity using mammograms from the latest examination (obtained 1 year previously) as a reference was significantly better (p = 0.03) than specificity using mammograms obtained 2 years previously.


CONCLUSIONS
Comparison mammograms are important for accurate diagnosis-in particular, for increasing specificity. The latest prior examination seems to be the optimal one for this purpose.
Sumkin
Jules H
JH
Department of Radiology, Imaging Research, Ste. 4200, University of Pittsburgh and Magee-Womens Hospital, 300 Halket St., Pittsburgh, PA 15213, USA.
Holbert
Brenda L
BL
Herrmann
Jennifer S
JS
Hakim
Christiane A
CA
Ganott
Marie A
MA
Poller
William R
WR
Shah
Ratan
R
Hardesty
Lara A
LA
Gur
David
D
D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography; D015588:Observer Variation; D012680:Sensitivity and Specificity