Breast Imaging Reporting and Data System category 3 for magnetic resonance imaging

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• The Breast Imaging Reporting and Data System (BI-RADS) category 3 indicates a probably benign finding with <2% malignancy risk.
• Limited data exists on BI-RADS category 3 utilization and defining features in magnetic resonance imaging (MRI).

Purpose of the Study:

• To define the appropriate use of BI-RADS category 3 in breast MRI.
• To clarify the imaging features of probably benign lesions on MRI.

Main Methods:

• Review of recent studies on BI-RADS category 3 in mammography, ultrasound, and MRI.
• Analysis of imaging features of lesions assessed as BI-RADS 3 on baseline MRI.

Main Results:

• BI-RADS category 3 use in MRI is comparable to mammography and ultrasound, with malignancy rates within the target range.
• Specific findings like background parenchymal enhancement variations and intramammary lymph nodes are benign.
• Appropriate BI-RADS 3 MRI findings include round, distinct foci; oval masses with circumscribed margins and homogeneous enhancement; and focal/regional nonmass enhancement without suspicious features.

Conclusions:

• BI-RADS category 3 can be appropriately applied to specific findings on baseline breast MRI.
• Further definition of probably benign lesion features in MRI enhances diagnostic accuracy and patient management.