BI-RADS is an acronym for Breast Imaging-Reporting and Data System, a quality assurance tool originally designed for use with mammography. The system is a collborative effort of many health groups but is published and trademarked by the American College of Radiology (ACR).
The system is designed to standardize reporting. The document focuses on patient reports used by medical professionals, not "lay reports" that are provided to patients.
The BI-RADS is published by ACR in the form of the BI-RADS Atlas. As of 2007 the Atlas is divided into 3 publications:
While BI-RADS is a quality control system, in day-to-day usage the term "BI-RADS" refers to the mammography assessment categories. These are standized numerical codes typically assigned by a radiologist after interpreting a mammogram. This allows for concise and unambigious understanding of patient records between mulitiple doctors and medical facilities.
The assessment categories were developed for mammography and later adapted for the MRI and Ultrasound Atlases. The summary of each category, given below, is identical for all 3 modalities.
Category 6 was added in the 4th edition of the Mammography Atlas.
BI-RADS Assessment Categories are:
- 0: Incomplete
- 1: Negative
- 2: Benign finding(s)
- 3: Probably benign
- 4: Suspicious abnormality
- 5: Highly suggestive of malignancy
- 6: Known biopsy – proven malignancy
Breast Composition Categories
- 1: Almost entirely fat
- 2: Scattered fibroglandular densities
- 3: Heterogeneously dense
- 4: Extremely dense
- American College of Radiology (ACR) Breast Imaging Reporting and Data System Atlas (BI-RADS® Atlas). Reston, Va: © American College of Radiology; 2003