Why It Is Done

An MRI of the breast is done to:

• Find breast cancer . Breast MRI may be done when a mammogram or breast ultrasound scan cannot tell if a lump is cancer.
• Check women who are at increased risk for breast cancer. This includes women with:
  • Gene changes (such as BRCA).
  • Close family members who have had breast cancer.
  • A history of radiation therapy to the chest as a child.
• Choose the best treatment for breast cancer. It may also be used to check breast tissue changes during treatment.
• Check breasts with nipple changes for signs of breast cancer. These changes include inverted nipples, nipples with scaly skin that flakes off, and nipples with abnormal discharge.
• Check women with breast implants. MRI may be used to look for breast cancer or to check if the implant is leaking.

Women at increased risk for breast cancer may have screening tests that alternate between MRIs and mammograms. This is done because the tests can detect different kinds of problems.

How To Prepare

Before your MRI test, tell your doctor and the MRI technologist if you:

• Are allergic to any medicines. The contrast material used for MRI does not contain iodine. If you know that you are allergic to the contrast material used for the MRI, tell your doctor before having another test.
• Are or might be pregnant.
• Have any metal implanted in your body. This helps your doctor know if the test is safe for you. Tell your doctor if you have:
  • Heart and blood vessel devices, such as a coronary artery stent, a pacemaker, an ICD (implantable cardioverter-defibrillator), or a metal heart valve.
  • Metal pins, clips, or metal parts in your body, including artificial limbs and dental work or braces.
  • Any other implanted medical device, such as a medicine infusion pump or a cochlear implant.
  • Cosmetic metal implants, such as in your ears, or tattooed eyeliner.
• Had recent surgery on a blood vessel. In some cases, you may not be able to have the MRI test.
• Have an intrauterine device (IUD) in place. An IUD may prevent you from having the MRI test done.
• Become very nervous in confined spaces. You need to lie very still inside the MRI magnet, so you may need medicine to help you relax.
• Have any other health conditions, such as kidney problems or sickle cell anemia, that may prevent you from having an MRI using contrast material.
• Are taking medicines or wearing a medicine patch. You may need to stop taking certain medicines for a time before, during, or after the MRI. And if you're wearing a medicine patch, the MRI may cause a burn at the patch site.

Arrange to have someone take you home after the test in case you are given a medicine ( sedative ) to help you relax.

You may be asked to sign a consent form that says you understand the risks of the test and agree to have it done.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form .

How It Is Done

An MRI of the breast is usually done by an MRI technologist. A radiologist usually studies the pictures to look for problems. But some other types of doctors may also do this.

Before the test

You will need to remove all metal objects (such as hearing aids, dentures, jewelry, watches, and hairpins) from your body because these objects may be attracted to the powerful magnet used for the test. If there is a possibility that you have metal fragments in your eyes from an accident or a surgery or because you work around metal, an X-ray or a CT scan will be done before the MRI to see if any metal is present. An X-ray or CT may also be done if there is a concern about metal fragments in your head or spine.

You will need to take off your clothes above the waist. You will be given a gown to cover your shoulders during the test. Empty your pockets of any coins and cards (such as credit cards or ATM cards) with scanner strips on them because the MRI magnet may erase the information on the cards.

During the test

During the test, you will lie on your stomach on a table that is part of the MRI scanner. Straps may be used to help keep your body in the best position. The table will slide into the machine part that holds the magnet. A device called a coil may be placed over or wrapped around the breast area.

Inside the scanner, you will hear a fan and feel air moving. You may also hear tapping or thumping noises as the MRI scans are taken. You may be given earplugs or headphones with music to lessen the noise. It is very important to hold completely still while the scan is being done. Otherwise, repeat scans may be needed. Also, you may be asked to hold your breath for short periods of time.

During the test, you may be alone in the scanner room. But the technologist will watch you through a window, and you will be able to talk to him or her through a speaker.

If contrast material is needed, the technologist will put it in a vein ( intravenous, or IV ) in your arm. The contrast material may be given over 1 to 2 minutes. Then more MRI scans are taken.

An MRI test usually takes 30 to 60 minutes but may last as long as 2 hours.

How It Feels

You will not have pain from the magnetic field or radio waves. The table you lie on may feel hard and the room may be cool. You may become uncomfortable from lying in one position for a long time.

Some people feel anxious (claustrophobic) inside the MRI machine. You may be given medicine (sedative) to help you relax.

If dye is used, you may feel some coolness when it is put into your vein.

In rare cases, you may feel:

• A tingling sensation in your mouth if you have metal dental fillings.
• Warmth in the breast. This is normal and does not need treatment unless it becomes bothersome. Tell the technologist if you:
  • Have any breathing problems.
  • Feel sick to your stomach.
  • Have a headache.
  • Feel dizzy.
  • Have pain.
  • Feel a burning sensation.
  • Have itchy skin.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Medical devices that have metal, such as a pacemaker or an ICD . These devices may not function properly or can cause problems during an MRI scan.
• Other types of metal, such as surgical clips. If these will interfere with a breast MRI, the test will not be done.
• Inability to remain still during the test.
• Being very overweight. This may affect your ability to fit into the opening of some standard MRI machines.

What To Think About

• Abnormal findings on a breast MRI often are not cancer. If the MRI has an abnormal result, your doctor will do other testing to find out if the problem is serious. This may involve doing an ultrasound test or a biopsy , or both.
• Sometimes your MRI test results may be different because you were tested at a different medical center or earlier test results are not available to compare to the new test findings.
• While MRI is a safe and valuable test for looking at your breast, it is much more costly than other methods, and it may not be available in your area.