MRI (magnetic resonance imaging) is a test that creates detailed images of organs, bones, and other structures inside your body. An MRI uses large magnets and a computer to make these images. It does not 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, a woman lies face down with her breasts positioned through holes in a 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 women with dense breast tissue
Finding early breast cancer in women at high risk
Checking for cancer in women who have implants or 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 that are not specific just to women. They also apply to men who have breast cancer symptoms.
The American Cancer Society advises breast MRI and a mammogram for some women at high risk for breast cancer. This includes:
Women with a BRCA1 or a BRCA2 gene mutation
Women with a mother, sister, or daughter with a BRCA1 or BRCA2 gene mutation
Women with a 20% to 25% or greater lifetime risk for breast cancer, based on family history and other factors
Women who have had radiation treatment to the chest between ages 10 and 30, such as for treatment of Hodgkin disease
Women with one of these genetic disorders: Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome
Women with a close family member who have one of the above genetic disorders
Your healthcare provider may have other reasons to advise breast MRI. Talk with your healthcare provider 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:
Women who are pregnant
People with pacemakers and other implanted devices
People with recently placed metal plates, rods, screws, and other surgical devices in the body
Your risks may vary depending on your general health and other factors. Make sure your healthcare provider knows about all your health conditions. Ask your healthcare provider which risks apply most to you.
Make a list of questions you have about the procedure. Discuss these questions and any concerns with your healthcare provider before the procedure. Consider bringing a family member or trusted friend to the medical appointment to help you remember your questions and concerns.
Your healthcare provider will explain the procedure to you. Ask him or her 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 is not clear.
Tell the healthcare provider if you are 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 provider if you are not able lie down for 30 to 60 minutes.
Metal in the body can be dangerous or they can affect the quality of the images taken during an MRI. Also tell the healthcare provider 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 provider 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 healthcare provider gives you.
Tell your healthcare provider or technologist doing the test if you:
Have ever had an imaging test (MRI or CT) with contrast dye
Are allergic to contrast dye, iodine, shellfish, or any medicines
Have a serious health problem. This includes diabetes and kidney disease.
Are pregnant or 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 healthcare provider's methods. In most cases, the breast MRI will follow this process:
You will be asked to remove your clothes and given a hospital gown to wear. You may be asked to remove jewelry or other objects.
If your procedure will be done with contrast dye, an IV line will be started in your hand or arm.
You will 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.
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.
You will be given earplugs or a headset to wear to help block out the noise from the scanner.
During the scan, you’ll hear a loud clicking noise. You will need to lie still. Any movement can cause problems with the quality of the scan.
At times, you may be told to hold your breath for a few seconds.
If contrast dye is used for your procedure, you may feel some effects when the dye is injected into the IV line. You may feel 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.
Your breasts may feel slightly warm, but this is normal.
Tell the technologist if you have any breathing trouble, sweating, numbness, or heart palpitations.
Once the scan has been completed, the table will slide out of the scanner and you will be helped off the table.
If an IV was inserted for contrast dye, it will be removed.
Get up slowly from the scanner table. This will help prevent dizziness. If you received sedatives for the procedure, you will need to rest until the sedatives wear off. You will need to have someone drive you home. Your healthcare provider 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 are nursing, don't breastfeed for 36 to 48 hours after a breast MRI with contrast dye.
Call your healthcare provider right away if you have any of these:
Fever of 100.4°F (38°C) or higher, or as directed by your healthcare provider
Pain, redness, or swelling at the IV site
Your healthcare provider may give you other instructions after the procedure.
Before you agree to the test or the 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