Applying the MRI BI-RADS in a High-Risk Population

The American College of Radiology Breast Imaging Reporting and Data System (ACR BI-RADS) has been very early used for the interpretation of breast MRI, also in high-risk women. In the general population, the application of the BI-RADS allowed for a very good diagnostic performance, although associated with rather low inter-reader agreement. This good performance was seen also for the application of the BI-RADS lexicon in screening high-risk women. Cancer in high-risk women can present with relatively subtle features on mammography or ultrasound, but MRI features of malignancy according to the BI-RADS lexicon are found in the vast majority of the cases and allow for a correct management. Some issues still have to be considered. First, for probably benign findings (BI-RADS 3), the lexicon fails to define exactly the lesion characteristics. Furthermore, areas of non-mass enhancement and foci can create problems regarding their best management in high-risk women. Finally, background parenchymal enhancement is usually easy to recognize, and it does not hide suspicious lesions but, in some cases, can be difficult to interpret and a short-term follow-up may be necessary.