The BI-RADS Breast Magnetic Resonance Imaging Lexicon

The Breast Magnetic Resonance Imaging Lexicon was designed to standardize interpretation and reporting of breast magnetic resonance (MR) imaging findings, ultimately improving communication between radiologists and clinicians and facilitating patient care. The lexicon includes 3 lesion types: mass, focus, and non-masslike enhancement. The mass category is analogous to the mass category in the mammography lexicon. Non-masslike enhancement is comparable with calcifications in the mammography lexicon. Unique to the MR lexicon is description of lesion enhancement. In addition, description of background enhancement allows assessment and communication of the sensitivity of the study. The Breast MR Imaging Lexicon is reviewed and images provided to illustrate these descriptor terminologies.