MRI (magnetic resonance imaging) is a test that creates detailed images of organs, bones, and other structures inside your body. MRI uses large magnets and a computer to make the images. It doesn't use radiation.

An MRI scanner is a large machine with a tunnel. You lie on a table that slides in and out of the tunnel. For a breast MRI, you would lie face down with your breasts positioned through holes in the table.

A breast MRI is often done with contrast dye. The dye is injected into a vein in the arm before or during the procedure. The dye can help create clearer images.

Breast MRI is most often used to check for breast cancer. Some common uses for breast MRI include:

• Examining possible problem spots seen on a mammogram
• Finding early breast cancer in dense breast tissue
• Finding early breast cancer in people at high risk for it
• Checking for cancer when you have scar tissue in the breasts
• Checking for leakage from a silicone gel breast implant
• Checking the size and exact location of breast cancer lesions
• Assessing a lumpectomy site in the years after breast cancer treatment
• Finding breast cancer that has spread into the chest wall
• Finding breast cancer that's returned after lumpectomy
• Monitoring for how well chemotherapy is working
• Assessing the cause of a newly inverted nipple

The above reasons aren't specific to women. They also apply to men who have breast cancer symptoms.

The American Cancer Society advises breast MRI and a mammogram starting at about age 30 for some people at high risk for breast cancer. This includes:

• People with a BRCA1 or a BRCA2 gene mutation
• People with a first-degree relative (parent, sibling, or child) with a BRCA1 or BRCA2 gene mutation
• People with a 20% to 25% or greater lifetime risk for breast cancer, based on family history and other factors
• People who have had radiation treatment to the chest between ages 10 and 30, such as for treatment of Hodgkin disease
• People with one of these genetic disorders: Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome
• People with a close family member who has one of the above genetic disorders

Your doctor may have other reasons to advise breast MRI. Talk with your doctor about the reason for your MRI.

All procedures have some risks. The risks of this procedure may include:

• Allergic reaction to the contrast dye
• Disruption of any metal in the body
• False positive results that lead to unneeded breast biopsy
• Failure to detect calcium deposits in the breast that may indicate breast cancer
• Discomfort from having to lie still for a long time
• Anxiety from being inside the MRI scanner

Some people shouldn't have an MRI. This can include:

• People who are pregnant
• People with pacemakers and other implanted devices
• People with recently placed metal plates, rods, screws, or other surgical devices in the body

Your risks may vary depending on your general health and other factors. Make sure your doctor knows about all your health conditions. Ask your doctor which risks apply most to you.

Make a list of questions you have about the procedure. Discuss these questions and any concerns with your doctor before the procedure. Consider bringing a family member or trusted friend to the medical appointment to help you remember your questions and concerns.

Your doctor will explain the procedure to you. Ask them any questions you have. You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully. Ask questions if anything isn't clear.

Tell the doctor if you're claustrophobic or have trouble being in enclosed spaces and may not be able to lie still inside the scanning machine. You may be given a sedative. Also tell your doctor if you're not able to lie down for 30 to 60 minutes.

Metal in the body can be dangerous or affect the quality of the images taken during MRI. Also tell the doctor if you:

• Have a pacemaker or cardiac defibrillator or have had heart valves replaced
• Have any type of implanted pump, such as an insulin pump or medicine port
• Have a cochlear implant
• Have an older intracranial aneurysm clip
• Have an IUD
• Have removable dental work
• Have any surgical metal plates, clips, sutures, pins, screws, rods, staples, or wire mesh in your body. Most orthopedic devices shouldn't pose a risk, but make sure your doctor knows about any metal in your body.
• Have a prosthetic device
• Have a neurostimulator or bone-growth stimulator
• Have any other type of metal implant
• May have metal fragments anywhere in your body
• Have tattoos or permanent eye makeup
• Ever had a bullet wound
• Have ever worked with metal (for example, grinding or welding)
• Have any type of body piercing
• Are wearing a medicine patch

Follow any other instructions your doctor gives you.

Tell your doctor or the technologist doing the test if you:

• Have ever had an imaging test, such as MRI or CT scan, with contrast dye
• Are allergic to contrast dye, iodine, shellfish, or any medicines
• Have a serious health problem, such as diabetes or kidney disease
• Are pregnant, may be pregnant, or are breastfeeding

You may have your procedure as an outpatient. This means you go home the same day. Or it may be done as part of a longer stay in the hospital. The way the procedure is done may vary. It depends on your condition and your doctor's methods. In most cases, the breast MRI will follow this process:

1. You'll be asked to remove your clothes and given a hospital gown or scrubs to wear. You may be asked to remove jewelry or other objects.
2. If your procedure will be done with contrast dye, an I.V. (intravenous) line will be started in your hand or arm.
3. You'll lie face down on a mobile bed. Your breasts will be positioned through cushioned openings. The bed will then be moved into the magnet of the MRI machine. Pillows or straps may be used to prevent movement during the procedure.
4. The technologist will be in a separate room inside the larger MRI room where the scanner controls are located. You'll be in constant sight of the technologist through a window. Speakers inside the scanner will let the technologist talk with you. You can let the technologist know if you have any problems during the procedure.
5. You'll be given earplugs or a headset to wear to help block out the noise from the scanner.
6. During the scan, you'll hear a loud clicking noise. You'll need to lie still. Any movement can cause problems with the quality of the scan.
7. At times, you may be told to hold your breath for a few seconds.
8. If contrast dye is used for your procedure, you may feel some effects when the dye is injected into the I.V. line. You may have a flushing sensation or coldness, a salty or metallic taste in your mouth, a brief headache, itching, nausea, or vomiting. These effects usually only last for a few moments.
9. Your breasts may feel slightly warm, but this is normal.
10. Tell the technologist if you have any breathing trouble, sweating, numbness, or heart palpitations.
11. Once the scan has been completed, the table will slide out of the scanner and you'll be helped off the table.
12. If an I.V. was inserted for contrast dye, it'll be removed.

Get up slowly from the scanner table. This will help prevent dizziness. If you received sedatives for the procedure, you'll need to rest until the sedatives wear off. You'll need to have someone drive you home. Your doctor will talk with you about the results in a follow-up visit.

If contrast dye was used during your procedure, you may be watched for any side effects or reactions to the dye. These may include itching, swelling, rash, or trouble breathing. If you're nursing, don't breastfeed for 36 to 48 hours after a breast MRI with contrast dye.

Call your doctor right away if you have any of these:

• Fever of 100.4°F (38°C) or higher, or as directed by your doctor
• Pain, redness, or swelling at the I.V. site

Your doctor may give you other instructions after the procedure.

Before you agree to the test or procedure, make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person's qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how you will get the results
• Who to call after the test or procedure if you have questions or problems
• How much you will have to pay for the test or procedure