Breast MRI is a safe and accurate way to make detailed images of the interior of your body. It uses a magnetic field and radio waves. Breast MRI was approved by the FDA as an additional tool to help diagnose breast cancer.
MRI is the most reliable method for evaluating breast implants for rupture or leakage. MRI is useful in looking at dense breast tissue, scar tissue at a prior lumpectomy site, and breast abnormalities that can be felt but are not visible with mammography or ultrasound. MRI is used to help determine whether breast cancer has spread to the chest wall, which may affect treatment. It is also helpful in distinguishing if a cancer is limited to one area of the breast or is multi-focal, involving more than one area.
Mammography is the first test you should continue to have to search for early signs of breast cancer — MRI will not replace mammography. Breast MRI for screening is appropriate for a small group of patients who are most likely to benefit.
In March 2007 the American Cancer Society updated its screening guidelines to include breast MRI for women at high risk for developing breast cancer. The following women are considered high risk:
- Known BRCA1 and BRCA 2 gene mutation carriers (this is found with specialized genetic testing)
- First degree relatives of known BRCA1 and BRCA2 gene mutation carriers
- Lifetime risk of 20-25% or greater (as assessed by one of the established methods including the Gail Model)
Radiation treatment to the chest between the ages of 10 and 30 (usually someone treated with Hodgkins Lymphoma)
And a few rare syndromes: Li-Fraumeni, Cowden, and Bannayan-Riley-Ruvalcaba
There isn't enough evidence for MRI screening in other high risk situations:
- 15-20% lifetime risk
- LCIS (lobular carcinoma in situ) or ALH (atypical lobular hyperplasia) on biopsy
- ADH (atypical ductal hyperplasia) on biopsy
- Very dense breast tissue diagnosed on mammogram
- History of breast cancer
Screening MRI is not indicated for women at average risk (less than 15% lifetime risk) for developing breast cancer.
While MRI has several potential benefits in helping to investigate breast concerns, there are limitations. The two main limitations are:
- The cost of an MRI is several times that of a mammogram or ultrasound
- An MRI is not able to detect very small calcifications in the breast that can be suspicious for breast cancer.
Patient Experience
During the MRI, you will lie on your stomach on the scanning table. Your breasts hang into a depression in the table, which contains coils that detect the magnetic signal. There is no pain associated with an MRI.
After an initial series of images have been taken, you may be given a contrast agent (gadolinium) intravenously (injection into the vein) to enhance the MRI image. Additional images are then taken. The entire imaging session takes about one hour.
After Your Exam
Your MRI images will be interpreted by a board certified radiologist who specializes in breast care, and the findings will be reported to the your healthcare provider. Your healthcare provider will contact you to discuss the results.
Breast MRI is available at: 
