Breast Cancer Prevention and Early Detection

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Mammograms

Breast magnetic resonance imaging

For certain women at high risk for breast cancer, the American Cancer Society recommends screening magnetic resonance imaging (MRI) along with a yearly mammogram. MRI is not recommended as a screening tool by itself, because although it is a sensitive test, it can still miss some cancers that mammograms would detect. Breast MRI is also sometimes be used in other situations, such as to better examine suspicious areas found by a mammogram or to look more closely at the breast in someone who hase already been diagnosed with breast cancer.

MRI scans use magnets and radio waves instead of x-rays to produce very detailed, cross-sectional images of the body. The most useful MRI exams for breast imaging use a contrast material (called gadolinium) that is injected into a catheter in a vein (IV) in the arm before or during the exam. This improves the ability of the MRI to clearly show breast tissue details.

Although MRI can find some cancers not seen on than mammogram, it is also more likely to find something that turns out not to be cancer (called a false positive). False-positive findings have to be checked out to know that cancer isn’t present, which means coming back for further tests and/or biopsies. This is why MRI is not recommended as a screening test for women at average risk of breast cancer, as it would result in unneeded biopsies and other tests in a large portion of these women.

Because breast MRI is expensive, it often needs to be approved by an insurance company before the scan is done. Most private insurance that pays for mammogram screening will probably also pay for MRI for screening tests if a woman can be shown to be at high risk. It can help to go to a center with a high-risk clinic, where the staff has experience getting approval for breast MRIs.

What to expect when you get a breast MRI

MRI scans can take a long time—often up to an hour. For a breast MRI, you have to lie inside a narrow tube, face down, on a platform specially designed for the procedure. The platform has openings for each breast that allow them to be imaged without being compressed. The platform contains the sensors needed to capture the MRI image. It is important to stay very still throughout the exam.

Lying in the tube can feel confining and may upset people with claustrophobia (a fear of enclosed spaces). The machine also makes loud buzzing and clicking noises that you might find disturbing. Some places will give you headphones with music to block this noise out.


Last Medical Review: 09/10/2014
Last Revised: 09/10/2014