Suspicious abnormality—biopsy should be considered (4a, 4b, 4c may be included to reflect increasing suspicion)
Highly suggestive of malignancy
Highly suggestive of malignancy—appropriate action should be taken
Known, biopsy-proven malignancy—appropriate action should be taken
SOURCE: American College of Radiology (2003).
physician’s skill. In this section, current well-established performance measures are reviewed and their strengths and weaknesses are discussed. These measures should be made separately for screening examinations (done for asymptomatic women) and diagnostic examinations (done for women with breast symptoms or prior abnormal screening mammograms) because of the inherent differences in these two populations and the pretest probability of disease (Dee and Sickles, 2001; American College of Radiology, 2003). However, for simplicity, in the discussion below “examinations” or “mammograms” are used without designating whether they are screening or diagnostic because the mechanics of the measures are similar in either case.
Before describing the measures, it is important to clearly define a positive and negative test. The Breast Imaging Reporting and Data System (BI-RADS) was developed by the American College of Radiology (ACR), in collaboration with several federal government agencies and other professional societies in order to create a standardized and objective method of categorizing mammography results. The BI-RADS 4th Edition identifies the most commonly used and accepted definitions, which are based on a standard set of assessments first promulgated by the ACR in 1992 and modified slightly in 2003. Table 2–1 outlines terms used to define test positivity/negativity as found in the 1st and 4th editions of BI-RADS.
The assessments are intended to be linked to specific recommendations for care, including continued routine screening (Category 1, 2), immediate additional imaging such as additional mammographic views and ultrasound or comparison with previous films (Category 0), short-interval (typically 6 months) follow-up (Category 3), or biopsy consideration (Category 4) and biopsy/surgical consult recommended (Category 5).