What does your mammogram number mean?

BI-RADS System for Breast Imaging
Mammograms

Breast Mammogram

Breast Imaging Reporting and Data System

The American College of Radiology (ACR) came up with a standard way to describe mammogram findings and results. In this system, the results are categorized, giving each report number 0 through 6. This system is called the Breast Imaging Reporting and Data System (BI-RADS). Having a standard way of reporting mammogram results allows physicians, to ‘relate’ the level of concern, using the same words and terms, which can help ensure better follow up of suspicious findings.

 

BI-RADS 0

Need more imaging/work-up

More imaging required; does NOT necessarily mean there is something ‘bad’, just a finding that needs more images to better define.

 

BI-RADS 1

Normal, no findings at all

No findings of concern.

 

BI-RADS 2

Normal, but with a finding

A finding that is known to be normal/benign, such as a cyst, or a finding that has been previously evaluated and remains stable over time.

 

BI-RADS 3

“Likely” benign

A ‘likely’ benign finding. These findings usually have had additional imaging at the time of their presentation, but may need a follow up typically in 6 months to confirm stability. Likelihood of cancer 3%.

BI-RADS 4

Abnormal finding

An abnormal/inderminate finding, requiring biopsy. In some institutions, these are divided into subclasses: 4a, 4b, 4c, depending on the degree of suspicion. These findings are best biopsied, rather than followed. Likelihood of cancer about 20-25%.

BI-RADS 5

Very suspicious finding

Very suspicious finding, requiring biopsy. These are cancer > 90% of the time (but not always).

BI-RADS 6

Already proven cancer

These are findings that have already been proven cancerous by a biopsy. Typically, BIRADS 6 studies are found during the evaluation of patients diagnosed with breast cancer.