Using MRI to Detect Breast Cancer Breast MRI (magnetic resonance imaging) is a test that should not be used to distinguish between benign (noncancerous) and malignant (cancerous) areas, in lieu of a breast biopsy. Due to false positive results, performing this test may increase the number of breastbiopsies that need to be performed. It is not appropriate to utilize breast MRI to evaluate a suspicious breast mass, or to follow these breast masses over time. Although MRI may detect tumors in dense breast tissue, the presence of dense breast tissue is not a reason to have a breast MRI scan. Breast MRI scanning cannot detect tiny specks of calcium (known as microcalcifications), which account for half of the cancers detected by mammography.

Talk to your doctor about whether you should have an MRI of the breasts.

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Is the Breast MRI Test Safe?

A breast MRI is safe. The test poses no risk to the average patient if appropriate safety guidelines are followed.

People who have had heart surgery and people with the following medical devices can be safely examined with MRI:

• Surgical clips or sutures
• Artificial joints
• Staples
• Most heart valve replacements
• Disconnected medication pumps
• Vena cava filters
• Brain shunt tubes for hydrocephalus

Some conditions may make an MRI exam inadvisable. Tell your doctor if you have any of the following conditions:

• Heart pacemaker
• Cerebral aneurysm clip (metal clip on a blood vessel in the brain)
• Implanted insulin pump (for treatment of diabetes), narcotics pump (for pain medication), or implanted nerve stimulators ("TENS") for back pain
• Metal in the eye or eye socket
• Cochlear (ear) implant for hearing impairment
• Implanted spine stabilization rods
• Severe lung disease
• Uncontrolled gastroesophageal reflux (a condition causing severe heartburn)

In addition, tell your doctor if you:

• Are pregnant
• Weigh more than 300 pounds
• Are not able to lie on your back for 30 to 60 minutes
• Have claustrophobia (fear of closed or narrow spaces)

How Long Is the Breast MRI Test?

Allow 1 1/2 hours for your breast MRI exam. In most cases, the procedure takes 45 to 60 minutes, during which time several dozen images are obtained.