When a radiologist interprets a mammogram, he or she assigns a score to it — a grade, if you will — that represents how healthy your breasts looked.
Did anything look abnormal? How serious is the abnormality that was found? This and other information is efficiently summed up in one number, called the BI-RADS score. BI-RADS scores range from 0 to 6. Here's what each grade usually means:
0: This score identifies a mammogram study that is still incomplete. The x-ray may have been cloudy, making it difficult to read the images. This can happen, for example, if you moved at the precise moment the picture was taken.
In any case, further information is needed to make a final assessment and assign the true BI-RADS score. If you've received a BI-RAD score of 0, you need to make sure that additional imaging is done, such as some extra mammography views or an ultrasound.
1: This score is good news! It means that your mammogram is negative (that is, no evident signs of cancer were found) and that you should continue to have routine screenings.
2: This score also means that your mammogram is normal, with no apparent cancer, but that other findings (such as cysts) are described in the report. You'll be instructed to continue your routine screening.
3: Now we are entering a gray zone. A BI-RADS score of 3 means that your mammogram is probably normal but that there's an approximately 2 percent chance of cancer. You'll be asked to follow-up with a repeat mammogram in six months. And if you have a family or personal history of breast cancer, the radiologist may opt to do more tests now rather than wait.
4: This score means that the findings on your mammogram are suspicious and that there is an approximately 20 percent to 35 percent chance that a breast cancer is present. To make a diagnosis, the doctors will need to perform a biopsy to get a small tissue sample. More than 90 percent of women with a BI-RADS score of 4 can have a core biopsy done the same day, right in the breast-imaging facility.
5: This score means that your mammogram results are highly suspicious, with a 95 percent chance of breast cancer. You will need to have a biopsy for diagnosis. Talk to your doctors about what course of action to take.
6: This means that you have already been diagnosed with breast cancer and the pathologist has confirmed the diagnosis.
Why should you know your BI-RADS score? Because it will help ensure that you get the proper follow-up after your mammogram. It is part of what you need to know to actively participate in your medical care.