Breast MRI

Approved by the Cancer.Net Editorial Board, 04/2018

A breast magnetic resonance imaging (MRI) test is a diagnostic examination. It uses magnetic fields to capture multiple images of the breast tissue. These images are combined to create detailed, computer-generated pictures of the tissue inside your breasts.

Why might I need a breast MRI?

This test has many uses:

  • To look for breast cancer in women who are at a high risk for the disease. This is called screening.

  • To diagnose and evaluate breast tumors. This test may identify a small mass within a woman's breast better than a mammogram or ultrasound can. This is particularly true for women with very dense, non-fatty breast tissue.

  • To learn more about a cancer that is found by feeling the breast but not seen on a mammogram or ultrasound.

  • To find out more about the size of the tumor and extent of the spread after an initial breast cancer diagnosis. This is called staging the cancer.

  • To monitor how well chemotherapy is working to treat the cancer.

  • To evaluate the area where the cancerous breast tissue was removed as a part of follow-up care.

  • To learn if breast implants have ruptured.

Limitations of using breast MRI for cancer screening

A breast MRI is not a replacement for mammography. Although it is a highly effective test, a breast MRI may sometimes fail to find cancer that a mammogram detects. A breast MRI may also lead to a false-positive result. This means that the test finds a mass or other change, but it turns out not to be cancer. If this happens, your doctor may recommend a targeted ultrasound. If the area is still not seen with the ultrasound, he or she may recommend an MRI biopsy.

Preparing for a breast MRI

For best results, you may want to schedule your exam at certain times of your menstrual cycle. For example, if you are premenopausal, the MRI facility may ask you to schedule the procedure during days 5 through 15 of your menstrual cycle. Be sure to discuss this with your doctor.

When you schedule your MRI, you will get detailed instructions on how to prepare. Here are some general suggestions:

  • Tell your doctor about all the medications you are taking, as well as any drug allergies or other medical conditions you have.

  • Tell your doctor if there is any chance you may be pregnant.

  • Women who are breastfeeding should discuss the test with their doctor. Breast MRIs conducted while a woman is breastfeeding may not produce images that are clear enough for accurate interpretation. Women who are breastfeeding and get a breast MRI may want to stop breastfeeding for up to 2 days after the test. This allows their bodies to eliminate the contrast material, which is a special dye used in the test. The dye is called gadolinium.

  • Tell your doctor and the technologist performing your breast MRI about any metal implants or metal fragments you have in your body. These can cause serious complications when exposed to the MRI’s strong magnetic pull. People with pacemakers, for example, cannot have an MRI. Women with breast expanders that have valves also cannot have an MRI. Also tell your doctor and the technologist about any tattoos you have.

  • Consider asking whether you can bring music with you to the scan. Some facilities allow people to listen to music through headphones during the examination to help them relax.

  • Tell your doctor and technician if you have ever had a reaction to the contrast dye, gadolinium.

  • You may be asked to sign a consent form. It states you understand the benefits and risks of the breast MRI and agree to have the test done. Talk with your doctor about any concerns you have about the procedure.

Before the exam

You may receive a breast MRI in a hospital or outpatient clinic. A radiologist or radiology technologist may perform the test. A radiologist is a medical doctor who performs and interprets imaging tests to diagnose disease. A radiology technologist is specially trained and certified to perform MRI scans but not interpret them.

You will need to remove any jewelry or other metal objects you are wearing. You also may need to change into a hospital gown.

You will be given gadolinium through an intravenous (IV) line. A nurse or doctor will insert a small needle into a vein in your arm or hand. This needle is connected to a tube. Saline solution will flow through the IV line until gadolinium is injected at a specific point during the test. The dye will travel through your bloodstream and help create a clearer picture of your breasts.

People having a breast MRI for a ruptured implant will not need the contrast material. For some people, the contrast material causes allergic reactions. Or it may cause complications in people with kidney or liver problems. This is why it it important to tell your doctor about any health conditions you may have before the test.

A breast MRI is not painful. But if you receive an IV, you may feel discomfort when the needle is inserted. The saline solution in the IV may cause a cool feeling at the injection site.

You will need to lie still for most of the scan, which could become uncomfortable. The loud sounds coming from the machine may also make you uncomfortable. You may receive earplugs or earphones to wear during the test.

If you have a fear of being in small spaces, tell the radiologist before beginning the exam. The radiologist may be able to give you a medication to help you relax. Or someone else on your health care team may prescribe you a sedative that you can take in advance or bring with you to the MRI center.

During the procedure

The radiologist will help position you on a padded table specially designed for a breast MRI. You will lie face down on your stomach with your arms at your side and your head on a headrest. The table has openings for your breasts so they can be scanned without being squeezed.

The table will then slide into the MRI machine. This machine looks like a large donut with a narrow, tunnel-like opening. Some centers have MRI machines that are more open. These machines can accommodate larger people and help people who are afraid of small spaces.

You will need to lie very still during the 2 to 6 imaging sequences. Each sequence will last up to 15 minutes. You will know that the machine is taking images because you will hear extremely loud tapping and knocking sounds. You will be allowed to relax slightly between each imaging sequence but will need to maintain your body position as much as possible.

Your breasts may feel warm during the MRI. Or you may feel as if you have to urinate during the procedure. This is normal.

During the exam, the technologist will be in a nearby room, separated by a window. The technologist will be able to see you. And you will be able to communicate with him or her at all times through an intercom system.

The breast imaging session will last between 30 to 60 minutes. And the whole appointment should last no more than 90 minutes. Ask the technologist for a time estimate before you begin.

When the procedure is complete, you may have to remain on the table while the radiologist reviews the images to determine if additional images are needed.

After the procedure

You can expect to resume your normal activities, including driving, after the breast MRI exam, unless you were given a sedative. A radiologist will review the images from your breast MRI and send them to your doctor. Make sure to provide the testing center with a list of doctors to whom you want your test results sent. Your doctor will discuss the results with you at a follow-up appointment.

Questions to ask the health care team

Before having a breast MRI, consider asking your health care team the following questions:

  • Do I need an order (prescription) to schedule the test?

  • Does my insurance provider need to authorize this test beforehand?

  • Who will perform the exam?

  • What will happen during the breast MRI?

  • How long will the procedure take?

  • Can a friend or family member sit in the MRI room during my examination?

  • What are the risks and benefits of having a breast MRI?

  • Is the imaging facility accredited to perform breast MRIs?

  • When will I learn the results?

  • Who will explain the results to me?

  • What further tests may be necessary, depending on the results?

Related Resources

Magnetic Resonance Imaging (MRI)

Guide to Breast Cancer

More Information

RadiologyInfo.org: Magnetic Resonance Imaging (MRI) – Breast

Mayo Clinic: Breast MRI