What Your BI-RADS Score Means
After you have a mammogram or other breast imaging, a radiologist will read, or interpret, the images. They will then assign a BI-RADS score based on the findings and any recommended follow-up care.
Jump to:
What is a BI-RADS score?
Who created BI-RADS and why?
BI-RADS categories 0-6
BI-RADS and breast density
How a radiologist assigns a BI-RADS category
BI-RADS for mammogram, ultrasound, and MRI
Where to find your BI-RADS score
What to do after you get your results
BI-RADS frequently asked questions
What is a BI-RADS score?
BI-RADS stands for Breast Imaging Reporting and Data System. It is a standardized system radiologists use to describe breast imaging results and communicate recommendations for follow-up care. BI-RADS categories help explain what was found and help your healthcare provider determine whether routine screening, additional imaging, or another test may be appropriate.
BI-RADS categories range from 0 to 6, with each number representing a specific meaning. The BI-RADS category reflects the radiologist’s overall assessment of breast imaging. A BI-RADS category is not a breast cancer diagnosis. Instead, it helps you and your healthcare provider understand your results and what should happen next.
BI-RADS is widely used in the United States and around the world to categorize mammograms, breast ultrasounds, and breast MRIs. Using the same reporting system helps keep breast imaging results and recommendations clear and consistent across healthcare settings.
Who created BI-RADS and why?
The American College of Radiology (ACR) developed BI-RADS to create a standard way for radiologists to describe and report breast imaging findings. First introduced in 1993, BI-RADS helps healthcare providers clearly communicate breast imaging results and recommendations for next steps.
Federal mammography standards also require mammography reports in the United States to include an overall assessment of the findings, such as negative, benign, probably benign, suspicious, or highly suggestive of cancer. These assessment terms correspond closely with BI-RADS categories.
The standardized approach used with BI-RADS has also been applied to other areas of medical imaging. Today, the ACR has similar Reporting and Data Systems (RADS) for imaging of the liver, lungs, ovaries, prostate, thyroid, and other parts of the body.
BI-RADS categories 0 to 6 and what each score means
Each BI-RADS category, from 0 to 6, has a specific meaning and helps guide next steps. Some categories may lead to additional imaging, closer follow-up, or a biopsy. A BI-RADS category alone does not diagnose breast cancer.
BI-RADS categories and explanations are as follows:
BI-RADS 0: Incomplete
The radiologist needs more information. You will need additional breast imaging (such as a diagnostic mammogram, breast ultrasound, or breast MRI), and/or the facility may need to obtain prior breast imaging for comparison with your current imaging before making a recommendation. It is important for the radiologist to compare current mammogram findings with any prior mammogram findings, if available.
BI-RADS 1: Negative
There are no concerning findings. If you have no other breast concerns, you can typically return to your regular breast cancer screening schedule.
BI-RADS 2: Benign
The radiologist saw a finding but determined that it is benign, or non-cancerous. Examples include simple cysts and benign-appearing breast calcifications. The typical recommendation is to continue routine screening.
BI-RADS 3: Probably benign
A finding is very likely benign, with no more than a 2% likelihood of cancer. Rather than recommending a biopsy right away, the radiologist will usually recommend follow-up imaging starting in 6 months, with continued monitoring, often every 6 months, for up to 2 years to make sure the finding remains stable.
BI-RADS 4: Suspicious
A finding has features suspicious enough that a biopsy is recommended. The chance of cancer within this category varies widely, from greater than 2% to less than 95%. Because this range is so broad, BI-RADS 4 is divided into three subcategories:
BI-RADS 4A, 4B, and 4C
- BI-RADS 4A: Low suspicion for cancer. There is an approximate 2–10% chance that the finding is cancer.
- BI-RADS 4B: Moderate suspicion for cancer. There is an approximate 10–50% chance that the finding is cancer.
- BI-RADS 4C: High suspicion for cancer. There is an approximate 50–95% chance the finding is cancer.
A BI-RADS 4 result does not mean you have cancer; it means that a finding on a mammogram was suspicious enough to check with a biopsy. Only a biopsy can confirm cancer.
BI-RADS 5: Highly suspicious
The imaging has features that are highly suspicious for cancer, with at least a 95% likelihood of cancer. A biopsy is recommended.
BI-RADS 6: Known biopsy-proven malignancy
This category is different from the others because breast cancer has already been confirmed by a biopsy in this case. This category may be used on breast imaging performed after the diagnosis but before treatment, such as imaging used to further evaluate the known cancer or to help plan treatment.
BI-RADS and breast density
Dense breast tissue is a risk factor for breast cancer. A radiologist determines breast density by looking at how much fibroglandular tissue is present compared with fatty tissue in your breasts.
Like a BI-RADS category, breast density is also reported on your mammogram. While both are part of your report, they describe different things and can be easy to confuse. There are four categories of breast density: A (almost entirely fatty), B (scattered areas of fibroglandular density), C (heterogeneously dense), and D (extremely dense).
Breasts that fall into categories C and D are considered dense breasts. Categories A and B are considered not dense. If you have been told that you have dense breasts, you should discuss the screening schedule that is appropriate for you with your healthcare provider. The majority of the time, a breast MRI will be needed to more distinctly and accurately see inside the breast tissue and determine if any cancer may be present.
Dense Breasts Q&A Guide
Nearly half of women over 40 have dense breasts. This free guide answers the most common questions so you can advocate for the screening that is right for you.
Get the Free GuideHow a radiologist assigns a BI-RADS category
When reading your mammogram, the radiologist looks for findings that may need closer attention, including:
- Masses: A mass, also called a tumor, is an area that takes up space within the breast. The radiologist looks at its size, shape, and edges, as well as whether it is new or has changed compared with previous mammograms.
- Calcifications: Calcifications are small calcium deposits in the breast that appear as white spots, similar to grains of salt, on a mammogram. The radiologist looks at their size, shape, number, and pattern, as well as whether they are new or have changed over time.
- Asymmetries: An asymmetry is an area of breast tissue that looks different from the surrounding tissue or the corresponding area of the opposite breast. The radiologist may also compare it with previous mammograms to see if it is new or has changed.
- Architectural distortion: This occurs when the normal pattern of breast tissue appears pulled, twisted, or distorted, even when there is no clear mass.
- Changes in the normal breast pattern: The radiologist also looks for other changes in the usual appearance of your breast tissue, especially when comparing your current mammogram with previous images.
The radiologist considers all of the imaging findings together when assigning the final BI-RADS category. Individual findings are not given their own separate BI-RADS scores.
BI-RADS for mammogram, ultrasound, and MRI
Mammograms, breast ultrasounds, and breast MRIs can each receive their own BI-RADS category. The category assigned to each report helps determine whether you need additional imaging, short-term follow-up, or a biopsy.
For example, your screening mammogram may show new calcifications in your left breast. If the radiologist needs additional mammogram images to better evaluate the calcifications, your screening mammogram may be given a BI-RADS 0 (incomplete: additional imaging is needed).
You would then return for a diagnostic mammogram. If the additional images show that the calcifications do not have suspicious features but the radiologist wants to make sure they remain stable, your diagnostic mammogram may be given a BI-RADS 3 (probably benign). The radiologist may recommend another diagnostic mammogram in 6 months.
If the calcifications remain stable during the recommended follow-up period, they are considered benign and given a BI-RADS 2 (benign) category. You can then return to routine screening. The finding is BI-RADS 2 rather than BI-RADS 1 (negative) because the calcifications are still visible, but are considered stable since the recommended follow-up has been completed.
Not all follow-up involves mammograms. Depending on what was found, the radiologist may recommend follow-up with a breast ultrasound or breast MRI instead. For example, certain findings seen on ultrasound may be followed with ultrasound, while a finding seen only on breast MRI may need follow-up with MRI.
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Find a Free MammogramWhere to find your BI-RADS score
Your BI-RADS category can usually be found near the end of your breast imaging report, often under a section called “Impression” or “Assessment.” This section summarizes the radiologist’s findings and recommendations for next steps.
If you are called back for additional imaging, the breast imaging team may review the results with you after the radiologist interprets your images and explain the recommended follow-up. A complete report with the findings and recommendations should also be sent to the healthcare provider who ordered your imaging.
Depending on the results, the imaging facility may help schedule the recommended next step, especially if additional testing is needed.
You may also receive a letter or electronic notification summarizing your results. This may not include the specific BI-RADS category. Instead, it may use terms such as “probably benign,” “additional imaging is needed,” or “follow-up imaging is recommended in 6 months.” These terms can help explain what the radiologist found and what you should do next.
Ask the healthcare provider who ordered your imaging about your BI-RADS category, what it means, and what next steps are recommended.
What to do after you get your results
If you receive abnormal results on your mammogram, you may be feeling anxious or have more questions.
Begin by talking to your provider about next steps. They should be able to explain your findings and recommendations for next steps. In some cases, you may need a referral to a breast specialist for further input or recommendations.
If you are getting a second opinion or going to a new imaging facility, ask them to send your previous breast images to the new facility before your appointment. Having your previous images allows the radiologist to compare them with any new imaging. Many facilities can send images electronically, but if not, you may need to request a copy of your images on a disc from the radiology department and bring it to your appointment.
NBCF is here to help
NBCF offers support to help you understand complex information and navigate abnormal or uncertain breast imaging results. NBCF also offers resources for free and low-cost mammograms for those who are uninsured or concerned about the cost of breast imaging. If cost is keeping you from getting recommended breast imaging, resources may be available to help.
Patient Navigation Program
If you have been called back or received an abnormal result, you don’t have to figure out the next steps alone. NBCF Patient Navigators help guide you through what comes next, at no cost.
Learn About Patient NavigationFrequently asked questions about BI-RADS
Is BI-RADS 4 cancer?
Not necessarily. BI-RADS 4 means that an imaging finding is suspicious enough that a biopsy is recommended, but it does not mean that the finding is definitely cancer. Overall, BI-RADS 4 findings have a greater than 2% but less than 95% chance of being cancer. Because this category covers such a wide range, it is divided into BI-RADS 4A, 4B, and 4C based on the level of suspicion.
What is the difference between BI-RADS 4A, 4B, and 4C?
BI-RADS 4 is divided into three subcategories based on how suspicious a finding appears:
- BI-RADS 4A: Low suspicion for cancer, with a greater than 2% but no more than 10% chance of malignancy.
- BI-RADS 4B: Moderate suspicion for cancer, with a greater than 10% but no more than 50% chance of malignancy.
- BI-RADS 4C: High suspicion for cancer, with a greater than 50% but less than 95% chance of malignancy.
A biopsy is recommended for findings in all three BI-RADS 4 subcategories.
What BI-RADS category requires a biopsy?
A biopsy is generally recommended for BI-RADS 4 and BI-RADS 5 findings. BI-RADS 4 means the finding is suspicious, with a greater than 2% but less than 95% chance of cancer. BI-RADS 5 means the finding is highly suggestive of cancer, with a 95% or greater chance of malignancy. In both cases, a biopsy is recommended.
What is a normal BI-RADS category?
BI-RADS 1 and BI-RADS 2 are both reassuring results that generally do not require additional imaging follow-up beyond routine screening. BI-RADS 1 means the imaging is negative, with no abnormal findings. BI-RADS 2 means there is a finding, but it has been determined to be benign, or noncancerous.
What is the difference between a BI-RADS category and breast density?
A BI-RADS category describes the radiologist’s overall assessment of your breast imaging and helps determine whether you need additional evaluation or follow-up. Breast density describes the amount of fibrous and glandular tissue in the breasts compared with fatty tissue. Breast density is reported separately from your BI-RADS assessment.
Does a higher BI-RADS category always mean cancer?
No. In general, a higher BI-RADS category, such as a score of 4 or 5, means there is greater concern that a finding could be cancer, but imaging alone cannot confirm a cancer diagnosis. A biopsy is needed to determine whether a suspicious finding is cancer. BI-RADS 6 differs from the other categories because it is used when a previous biopsy has already confirmed cancer.
Where do I find my BI-RADS category?
Your BI-RADS category can usually be found near the end of your breast imaging report, often under a section called “Impression” or “Assessment.” This section also typically includes the radiologist’s recommendations for any next steps.
Can my BI-RADS category change?
Yes. A BI-RADS category can change after additional imaging or over time.
What if I’m not okay with “probably benign” (BI-RADS 3)?
BI-RADS 3 means a finding is “probably benign,” with a 2% or less chance of malignancy. Short-term follow-up imaging is typically recommended to make sure the finding remains stable. If you are not comfortable with this and want to hear about other options, including breast biopsy, talk to your provider about a referral to a breast specialist. If possible, request that a breast imaging radiologist, who specializes in breast imaging, reads your mammogram.
Does BI-RADS have anything to do with cancer staging?
No. Cancer staging occurs after a cancer diagnosis and considers factors such as tumor size, lymph node involvement, and whether cancer has spread elsewhere.
Sources
American Cancer Society
American College of Radiology
U.S. Food and Drug Administration