From the Guidelines
The BI-RADS system is a crucial tool for breast cancer screening and diagnosis, and its categories should be used to guide management decisions, with Category 1 and 2 recommending routine screening, Category 3 recommending short-term follow-up, and Categories 4 and 5 necessitating tissue diagnosis using core needle biopsy or needle localization excisional biopsy 1. The BI-RADS (Breast Imaging-Reporting and Data System) is a standardized classification system used by radiologists to report mammogram, ultrasound, and MRI findings of the breast. It categorizes breast imaging results on a scale from 0 to 6, helping to standardize reporting and guide management decisions.
- Category 0 indicates an incomplete assessment requiring additional imaging
- Category 1 represents negative findings with no abnormalities
- Category 2 shows benign findings requiring no further action
- Category 3 indicates probably benign findings with a recommendation for short-term follow-up (typically 6 months)
- Category 4 (subdivided into 4A, 4B, and 4C) suggests suspicious abnormalities with increasing probability of malignancy, requiring biopsy
- Category 5 represents highly suspicious findings with a high probability of malignancy (>95%), necessitating biopsy and treatment planning
- Category 6 is used for biopsy-proven malignancy According to the NCCN Recommendations for Screening Mammogram BI-RADS Assessment Categories 1–6, for BI-RADS category 3, diagnostic mammograms at 6 months, then every 6 to 12 months for 1 to 2 years as appropriate, are recommended, with biopsy performed if the lesion increases in size or changes its benign characteristics 1. For BI-RADS categories 4 and 5, tissue diagnosis using core needle biopsy (preferred) or needle localization excisional biopsy with specimen radiograph is necessary, with concordance between the pathology report and the imaging finding obtained 1. This system is valuable because it provides a common language for healthcare providers, ensures consistent communication of findings, helps determine appropriate follow-up care, and improves patient outcomes through standardized assessment and management of breast abnormalities.
From the Research
Overview of the BI-RADS System
- The Breast Imaging Reporting and Data System (BI-RADS) is a standardized system developed by the American College of Radiology to describe mammography, ultrasound, and magnetic resonance mammography findings 2.
- BI-RADS provides a structured reporting platform and quality assurance tool for breast imaging, including recommendations for protocol structure, terminology, and assessment categories 3.
Assessment Categories and Management Recommendations
- BI-RADS includes assessment categories (0-6) with corresponding management recommendations, which effectively communicate findings and estimate the risk of malignancy 2, 3.
- Studies have shown varying concordance rates between BI-RADS assessments and management recommendations, with higher concordance for categories 1, 2, 4, and 5, and lower concordance for categories 3 and 6 4.
Diagnostic Value of BI-RADS
- BI-RADS has been shown to improve the quality of diagnosis and prognosis in breast tumor diseases, particularly when used in conjunction with other imaging modalities such as contrast-enhanced ultrasound and shear wave elastography 5.
- The use of multiparametric ultrasound and feature disentanglement techniques has been proposed to enhance the diagnostic value of BI-RADS category 4 breast tumors 6.
Evolution and Future Directions
- BI-RADS has evolved over time, with the 5th edition introducing harmonization of lexicon terms and reporting structures across mammography, ultrasound, and MRI 3.
- Future directions for BI-RADS include its application to emerging breast imaging modalities and the development of more effective communication and data tracking systems 3.