Magnetic resonance imaging (MRI) of the breast — or breast MRI — is a test used to detect breast cancer and other abnormalities in the breast.
A breast MRI captures multiple images of your breast. Breast MRI images are combined, using a computer, to create detailed pictures.
A breast MRI usually is performed after you have a biopsy that's positive for cancer and your doctor needs more information about the extent of the disease. For some people, a breast MRI may be used with mammograms as a screening tool for detecting breast cancer. That group of people includes women with a high risk of breast cancer, who have a very strong family history of breast cancer or carry a hereditary breast cancer gene mutation.
A breast MRI is used to assess the extent of breast cancer. It's also used to screen for breast cancer in women thought to have a high risk of the disease.
Your doctor may recommend a breast MRI if:
If you're unsure whether you may be at high risk, ask your doctor to help you determine your personal risk estimate. A referral to a breast clinic or breast-health specialist may help you better understand your risk and your screening options.
A breast MRI is intended to be used along with a mammogram or other breast-imaging test — not as a replacement for a mammogram. Although it's a sensitive test, a breast MRI can still miss some breast cancers that a mammogram will detect.
A breast MRI is a safe procedure that doesn't expose you to radiation. But as with other tests, a breast MRI has risks, such as:
To prepare for a breast MRI, you will need to take these steps:
When you arrive for your appointment, a member of your health care team may give you a gown or robe to wear. You'll receive instructions on removing clothing and jewelry. If you have trouble being in a small, confined space, tell your doctor before your breast MRI. You may be given a mild sedative.
A dye (contrast agent) may be injected through an intravenous (IV) line in your arm to make the tissues or blood vessels on the MRI pictures easier to see.
The MRI machine has a large, central opening. During the breast MRI, you lie facedown on a padded scanning table. Your breasts fit into a hollow depression in the table, which contains coils that detect magnetic signals from the MRI machine. The entire table then slides into the opening of the machine.
The MRI machine creates a magnetic field around you, and radio waves are directed at your body. You won't feel the magnetic field or radio waves, but you may hear loud tapping and thumping sounds coming from inside the machine. Because of the loud noise, you may be given earplugs to wear.
During the test, the technologist monitors you from another room. You can speak to the technologist through a microphone. You'll be instructed to breathe normally but to lie as still as possible.
The breast MRI appointment may take 30 minutes to one hour.
During a breast MRI, you lie on your stomach on a padded scanning table. Your breasts fit into a hollow depression in the table, which contains coils that detect magnetic signals. The table slides into the large opening of the MRI machine.
A doctor specializing in imaging techniques (radiologist) reviews the images from your breast MRI, and a member of your health care team will contact you to discuss the results of the test.
A breast MRI can reveal abnormalities in your breast. A breast biopsy may be necessary to determine whether abnormal areas found on breast MRI are cancerous.