An Abbreviated Protocol for High-risk Screening Breast Magnetic Resonance Imaging: Impact on Performance Metrics and BI-RADS Assessment

Abstract

Rationale and objectives: Annual breast magnetic resonance imaging (MRI) is recommended to screen high-risk populations for breast cancer, although costs are significant. This study assesses the performance of an abbreviated MRI protocol as a resource-efficient approach for screening patients at high-risk of breast cancer, and assesses whether the abbreviated protocol alters the assigned Breast Imaging Reporting and Data System (BI-RADS) category.

Materials and methods: This is a prospective paired cohort study performed in an academic ambulatory setting. MRI images of women at high risk of breast cancer were reviewed using an abbreviated MRI protocol, followed by an immediate review of additional sequences included in a full diagnostic protocol. BI-RADS assessments, including all changes and interpretation times, were recorded for both the abbreviated and full protocol reviews. Cancer detection rate, positive predictive value 3 (PPV3), sensitivity, and specificity were calculated.

Results: A total of 1052 MRI cases were reviewed. The cancer detection rate was 13.3 per 1000 with a PPV3 of 30.4% based on the full protocol. Review of sequences included in the full protocol resulted in a change in the final BI-RADS assessments in 3.4% of the cases, the majority of which did not change clinical management with respect to biopsy. The sensitivity and specificity of the abbreviated and full protocols were not significantly different.

Conclusions: This pilot study of an abbreviated MRI protocol demonstrates effective performance in cancer detection. BI-RADS assessments were rarely altered with the additional information afforded by the full protocol. The abbreviated protocol holds promise for resource-efficient breast cancer screening in high-risk women.

Keywords: High-risk; abbreviated breast MRI protocol; breast cancer; screening.