The American College of Radiology came up with this fancy acronym to standardize breast imaging terminology and to better communicate screening results to the referring physician clearly and consistently. BI-RADS stands for Breast Imaging - Reporting and Data System.
However, you should know that there’s two categories of BI-RADS to consider and they are equally important.
BI-RADS Assessment Category, a score of 0-6 is used to communicate how significant an abnormal finding might be and how soon they’re recommending follow up or biopsy.
BI-RADS Reporting Breast Density, to classify breast density into four categories, a. mostly fatty tissue, b. some dense glandular and fibrous tissue, c. heterogeneously dense tissue to d. extremely dense tissue with very little fat.
Breast density can only be diagnosed by a mammogram, it can not be determined by the way your breasts feel, nor is not related to firmness or size.
If you are diagnosed with dense breast tissue a breast ultrasound is necessary to screen for breast cancer, mammogram alone is not enough.