Standard terminology and reporting– Breast Imaging Reporting & Data System: magnetic resonance imaging

Abstract

Magnetic resonance imaging (MRI) of the breast is the most sensitive test for breast cancer with a pooled sensitivity of 93% with multiple clinical indications. Dynamic contrast-enhanced MRI (DCE-MRI) is the backbone of any MRI protocol, enabling the simultaneous assessment of tumor morphology and semiquantitative enhancement kinetics that evaluate neoangiogenesis as a tumor-specific feature. Due to an overlap of morphologic and kinetic features between benign and malignant lesions, there are limitations in specificity (pooled specificity of 71%). The American College of Radiology (ACR) Breast Imaging-Reporting and Data System (BI-RADS) MRI atlas provides standardized terminology for breast MRI findings, report organization, assessment structure, and a classification system. For MRI of the breast, thus far, it provides morphological and functional descriptors for both DCE-MRI and T2-weighted imaging which constitute the typical breast MRI protocol, as well as recommendations for their combined analysis with the aim of assigning a final BI-RADS assessment category based on all descriptors which indicates the probability of malignancy of a lesion with the intent to minimize false-negative and false-positive findings. The final BI-RADS category (0–6) is based on the most suspicious finding in each breast. The BI-RADS MRI lexicon is widely used for reporting of MRI of the breast and is applicable at any given field strength.