Breast Cancer and MRI

Breast MRI (magnetic resonance imaging) is a test that may be used to distinguish between benign (noncancerous) and malignant (cancerous) areas. Performing this test may reduce the number of breast biopsies done to evaluate a suspicious breast mass. Although MRI can detect tumors in dense breast tissue, it cannot detect tiny specks of calcium (known as microcalcifications), which account for half of the cancers detected by mammography.

Is the Breast MRI Test Safe?

Yes, 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 may be obtained.

What Happens Before a Breast MRI?

Before a breast MRI, personal items such as your watch, wallet -- including any credit cards with magnetic strips (they will be erased by the magnet) -- and jewelry should be left at home or removed. Hearing aids should be removed before the test since they can be damaged by the magnetic field. Secured lockers are typically available to store personal possessions.

What Happens During a Breast MRI?

You will be asked to wear a hospital gown during your breast MRI.

As the MRI scan begins, you will hear the equipment making a muffled thumping sound that will last for several minutes. Other than the sound, you should experience no unusual sensations during the scanning.

Certain MRI exams require that you receive an injection of a contrast material. This helps identify certain anatomic structures on the scan images.

Feel free to ask questions or tell the technologist or your doctor if you have any concerns.

What Happens After a Breast MRI?

Generally, you can resume your usual activities and normal diet immediately after a breast MRI.

Your doctor will discuss the test results with you.