Sona Ajit Chikarmane MD, Abstract Co-Author: Nothing to Disclose

Catherine Streeto Giess MD, Presenter: Nothing to Disclose

Dorothy Amy Sippo MD, Abstract Co-Author: Nothing to Disclose

Robyn L. Birdwell MD, Abstract Co-Author: Nothing to Disclose

To determine (1) the prevalence and predictive value of BI-RADS 3, 4, and 5 findings on breast MRI; and (2) the impact of study indication (screening versus diagnostic) and patient risk factors (personal or family history of breast cancer) on the predictive value of BI-RADS categories.

An IRB approved, retrospective review of our breast MRI database from 2009-2011 (5778 contrast enhanced studies in 3360 patients) was performed. At our institution each breast receives an individual BI-RADS assessment. Breast MRI reports and electronic medical record were reviewed to obtain BI-RADS assessment, imaging features, patient demographics, and outcome data.

Overall, there were 9216 BI-RADS assessments assigned during the study period: 7879 (85.5%) BI-RADS 1/2, 567 (6.1%) BI-RADS 3, 715 (7.8%) BI-RADS 4, and 55 (0.6%) BI-RADS 5. The prevalence of BI-RADS 3, 4, and 5 was higher in studies performed for diagnostic (7.8%, 14.6%, 1.5%, respectively) than screening (5.2%, 4.0%, 0.07%) indications (p < 0.0001). A total of 734 biopsies were performed with 219 (29.8%) malignant and 515 (70.2%) benign outcomes. The overall negative predictive value (NPV) for BI-RADS 3 findings was 98.0% (11/567) with no difference observed by study indication (diagnostic, 98.4%; screening, 97.7%, p = 0.76). In patients without a personal or family history of breast cancer, the NPV of BI-RADS 3 was 100% (0/177). The overall malignancy rate of BI-RADS 4 and 5 was 22.5% (161/715) and 85.5% (47/55), respectively. Malignancy rates for BI-RADS 4 subcategories were 7.9% (4a), 23.5% (4b), and 59.7% (4c). A trend toward higher malignancy rate was observed in BI-RADS 4/5 in diagnostic versus screening indications (49.6% vs 22.9%, p = 0.09). The highest cancer rate for BI-RADS 4 and 5 categories was in patients undergoing screening for personal history of breast cancer (26.3%, 100%).

Inclusion of clinical indications and patient demographics in assessing the likelihood of malignancy may potentially lead to fewer benign biopsies and false negatives in certain populations, improving the predictive value of BI-RADS assessments in breast MRI.

Clinical indication and personal / family history should be considered when assessing likelihood of malignancy in findings detected on breast MRI, particularly in BI-RADS 3 category.

Chikarmane, S, Giess, C, Sippo, D, Birdwell, R, Is the Predictive Value of BI-RADS 3, 4, and 5 Findings Detected on Screening and Diagnostic Breast MRI affected by Study Indication?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013545.html