The Breast Imaging Reporting and Data System (BI-RADS) is a standardized system used to report and assess breast cancer risk. It plays a crucial role in breast cancer detection and diagnosis. Here’s what you need to know about BI-RADS:

BI-RADS Categories:

Category 0 (Incomplete): This category indicates that the imaging results are inconclusive, and follow-up imaging is necessary to make a clear diagnosis.

Category 1 (Negative): No abnormalities are detected, and routine screening is recommended.

Category 2 (Benign): A definite benign finding is present, and routine screening is recommended.

Category 3 (Probably Benign): Findings have a high probability of being benign (>98%), and a six-month follow-up is recommended.

Category 4 (Suspicious Abnormality): Findings are not characteristic of breast cancer but have a possibility of malignancy (3%–94%). Biopsy should be considered.

Category 5 (Highly Suspicious of Malignancy): Lesions with a high probability of being malignant (>= 95%) are detected. Immediate action is recommended.

Category 6 (Biopsy Proven Malignancy): The presence of malignancy is confirmed, and the patient is being imaged prior to definitive treatment.


Breast Density: BI-RADS also assesses breast density, which is classified into four levels:

A: Almost entirely fatty

B: Scattered areas of fibroglandular density

C: Heterogeneously dense

D: Extremely dense

The Impact of Breast Density: Women with dense breasts have a higher risk of breast cancer than those with fatty breasts. This increased risk is separate from the difficulty of detecting tumors on mammograms due to breast density.

It’s important to note that breast images may not always neatly fit into BI-RADS categories, and findings can vary within categories. Therefore, discussing your results with your healthcare provider is crucial, even if your breast imaging test results appear to be negative.

BI-RADS is a valuable tool in the early detection and assessment of breast cancer risk, helping healthcare providers make informed decisions about further testing and treatment. Regular breast cancer screenings, including mammograms, remain essential for early detection and timely intervention.