Missed and true interval and screen-detected XXXX in a population based screening program.

@entity5 @entity1 @entity0
RATIONALE AND OBJECTIVES: To increase radiologic knowledge, the distribution of mammographic features on prior screening mammograms of missed interval and screen-detected @entity5 was compared to the distribution on diagnostic mammograms of screen-detected @entity5 . The same variables were compared on mammograms of discordant and concordant screen-detected @entity5 . MATERIALS AND METHODS: The study was performed in M  re og Romsdal County, Norway, as a part of the quality assurance of the Norwegian @entity0 Screening Program. @entity1 were screened using analog techniques and diagnosed from 2002 to 2008. Prior and diagnostic mammograms of 81 interval and 123 screen-detected @entity0 in @entity1 aged 50 to 71 years were retrospectively reviewed and classified as either missed or true by four experienced breast radiologists. Mammographic features were classified according to a modified Breast Imaging Reporting and Data System. RESULTS: Thirty percent (24 of 81) of the interval @entity5 and 21% (26 of 123) of the screen-detected @entity5 were classified as missed. Calcifications, alone or in association with mass or asymmetry, tended to be more common on prior mammograms of missed @entity5 compared to diagnostic mammograms of screen-detected @entity5 (34% [17 of 50] vs 21% [26 of 123], P = .114), whereas an opposite trend was seen for mass (54% [27 of 50] vs 68% [84 of 123], P = .109). Similar results were seen when comparing discordant and concordant @entity5 . CONCLUSIONS: Calcifications represent a challenge in the interpretation of screening mammograms. For educational purposes, the importance of reviewing both interval and screen-detected @entity5 is obvious. Knowledge gained from systematic reviews might reduce the number of missed @entity5 on mammographic screening. Performing reviews according to established guidelines would make it possible to compare results across screening programs.
