Breast magnetic resonance imaging (MRI) uses magnetic fields to create an image of the breast. It is more invasive than mammography because a contrast agent is given through an IV before the procedure.
At this time, breast MRI is mostly used in breast cancer diagnosis and staging. It is also used in breast cancer screening for women at higher risk.
Breast MRI and breast cancer screening for women at higher risk of breast cancer
There is growing evidence that mammography plus breast MRI, compared to mammography alone, can increase detection of breast cancer in:
The American Cancer Society (ACS) and National Comprehensive Cancer Network (NCCN) recommend yearly screening with mammography plus breast MRI for some women at higher risk of breast cancer.
This includes women with:
- A BRCA1 or BRCA2 mutation
- A first-degree relative with a BRCA1/2 mutation, but personally have not been tested for BRCA1/2 mutations
- A strong family history of breast or ovarian cancer (for example, two or more first-degree relatives with breast cancer or two or more with ovarian cancer)
- Radiation treatment to the chest area before age 30
- Li-Fraumeni, Cowden or Bannayan-Riley-Ruvalcaba syndrome (or a first-degree relative with one of these syndromes or family has a known p53 or PTEN gene mutation)
- A greater than 20 percent lifetime risk of invasive breast cancer
- ACS and NCCN recommend women at higher risk of breast cancer begin screening at an earlier age than women at average risk.
Talk with your health care provider about breast cancer screening. Together, you can make a screening plan that is right for you.
Breast MRI for women with a personal history of breast cancer
Some studies suggest that for women diagnosed with cancer in one breast, mammography plus breast MRI can find breast cancer in the opposite (contralateral) breast better than mammography alone.
Breast MRI for women with dense breast tissue
Mammography plus breast MRI is under study for screening in women with dense breast tissue.
ACS recommends women with very dense breasts talk with their health care providers about the risks and benefits of screening with mammography plus breast MRI.
Timing of breast MRI screening
For premenopausal women, the best timing for breast MRI is day 7-15 of a menstrual cycle.
There is no recommended timing for breast MRI for women after menopause.
Breast MRI and breast cancer screening for women at average risk of breast cancer
Screening with mammography plus breast MRI is not recommended for women at average risk of breast cancer. Whether screening with breast MRI can benefit these women is under study.
Screening with breast MRI has some drawbacks.
- Breast MRI is more invasive than mammography because a contrast agent is given through an IV before the procedure. In rare cases, women can have a reaction to the contrast agent.
- Breast MRI has more false positive results than mammography.
- Some MRI centers cannot do an MRI of the breast or they do not have radiologists specially-trained to read images of the breast.
- Not all centers can do an MRI-guided biopsy to follow-up on an abnormal finding that can only be seen on a breast MRI (cannot be seen with other imaging such as mammography).