Magnetic resonance imaging (MRI) uses magnets and radiofrequency waves to produce detailed images of the body. Investigators have been studying the use of the technology for detection of breast cancer. Research shows the procedure has about 96 percent sensitivity in the ability to detect breast cancers, including those that are just a few millimeters in size. Breast MRI may also be able to detect some very early breast cancers long before they can be detected by mammography.
Researchers say MRI won't yet replace mammography as a screening tool for breast cancer. MRI is currently much more expensive than mammography and requires specific equipment and training. However, MRI may be an important additional screening tool for certain groups of women (like younger women with very dense breasts or those with a strong personal or family history of breast cancer). For women with breast scars, MRI may be able to differentiate between scar tissue and cancer. The procedure is useful for women with breast implants to evaluate leakage and look for signs of cancer. MRI may also be helpful in determining the spread of the cancer, potentially enabling a patient to undergo a lumpectomy rather than a mastectomy.