Breast Magnetic Resonance Imaging (MRI)

April 10, 2025

This page was reviewed under our medical and editorial policy by Hannah Chang, M.D., assistant professor, and Susan Yost, Ph.D., staff scientist, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte

Breast magnetic resonance imaging (MRI) is a test that creates detailed pictures of the breast’s internal structures. It is sometimes used in addition to mammograms or breast ultrasounds as part of breast cancer screening.

The care team might order a breast MRI for women at high risk for developing breast cancer to get a clearer view of suspicious areas found on a mammogram or to assess the extent of cancer after a diagnosis. It is also sometimes used to see if breast implants have ruptured.

What’s a Breast MRI?

A breast MRI is a noninvasive test that helps doctors see inside the breast without using radiation. Instead, it relies on a strong magnetic field, radio waves and a computer to create detailed images of the breast tissue. These images may reveal things that might not be visible on a mammogram or ultrasound, making it a valuable tool for diagnosing and evaluating breast conditions.

This test provides important information to help doctors better understand what is happening in the breast.

Why Would a Doctor Order a Breast MRI?

A doctor might order a breast MRI:.

• For women at high risk of breast cancer (sometimes alongside yearly mammograms for screening, because an MRI might miss some cancers that a mammogram would detect)
• As a follow-up after an abnormal area is detected on a mammogram
• If a woman has symptoms, such as unusual nipple discharge, that suggest breast cancer after other imaging tests
• If breast cancer has already been diagnosed to help determine the size and location of the tumor
• In women with silicone breast implants to check for implant leaks

Breast MRI Versus Mammogram

Breast MRIs and mammograms are both imaging tests used to detect breast cancer, but they work differently.

A mammogram uses low-dose X-rays to capture images of the breast and is the standard screening tool. On the other hand, a breast MRI uses magnetic fields and radio waves to create detailed images.

While an MRI is more sensitive and may find breast masses that a mammogram might miss, it is also more likely to detect noncancerous findings. This could lead to additional testing or biopsies that may not be necessary.

Women with dense breasts may benefit from both tests, but whether this improves overall outcomes is unclear.

Preparing for an MRI of the Breast

Patients typically do not need to do much to prepare for a breast MRI, but there are some important things to keep in mind. In a standard MRI, patients lie on a bed that moves into a narrow tube for the scan. If patients feel anxious about tight spaces, they should mention it to their provider, who may offer medication or suggest a less confining "open" MRI.

Before the MRI, patients need to inform their provider about any metal implants, such as heart valves, pacemakers or cochlear implants, as these could interfere with the procedure. Those with a history of working with sheet metal might require an eye test to check for metal fragments.

Since MRIs use strong magnets, all metal items must be removed, including jewelry, glasses and removable dental work. Patients will need to change into a hospital gown. If the MRI requires contrast material, patients should let their doctor know about any allergies, especially to contrast materials or iodine.

Why No Caffeine Before a Breast MRI?

Whether a patient may have caffeine before a breast MRI depends on the facility’s specific guidelines and the details of the exam. Generally, most patients do not need to follow a special diet or make significant changes to their routine before an MRI. However, it is always a good idea to check with the health care provider beforehand.

If there are any specific restrictions, the provider will provide clear instructions on what to avoid. Patients should follow any instructions given to ensure the test goes smoothly.

Breast MRI Positioning and Procedure

During a breast MRI, the patient lies face down on a special platform designed for the procedure. This platform has openings that allow the breasts to be positioned without compression and the built-in electronics to capture the images. The technologist positions the patient on the movable exam table and may use straps or bolsters to keep patients still during the scan.

Remaining still is vital to avoid blurry images, but the patient should focus on relaxing rather than tensing up. If there is any discomfort, the patient should inform the technologist, who is able to make adjustments to make the testing more comfortable.

The MRI itself is painless, though the table may feel hard or cold. Patients may request a blanket or pillow for added comfort. The machine produces loud thumping and humming noises, so earplugs or headphones are typically provided. Some centers may offer music to help pass the time.

The patient is able to communicate with the technologist through an intercom during the scan. If anxiety is an issue, the health care provider may prescribe medication to help the patient relax during the procedure.

Breast MRI With Contrast

If the goal of the breast MRI is to look for breast cancer, a contrast material called gadolinium is often used. This substance is injected into a vein in the arm during the exam to help highlight any abnormal areas of breast tissue. It is different from the dye used in computed tomography (CT) scans.

Patients should inform the technologist if they have any allergies or have had reactions to contrast material in the past.

It is normal to feel a cool sensation or slight flushing for a minute or two after the contrast is injected. The needle insertion might cause brief, minor discomfort as well.

Patients will continue to lie face down on the table with arms above the head until all of the pictures are taken.

Breast MRI Without Contrast

Contrast material is not used during a breast MRI if the test is being performed solely to check for a ruptured silicone breast implant. In this case, the MRI may successfully detect implant issues without contrast.

For this procedure, patients are positioned face down on the table, the table slides into the machine and patients remain still until all of the pictures are taken.

If the MRI is being performed for any other reason, such as evaluating for breast cancer, contrast is necessary. Without contrast, the MRI would not provide the detail needed to identify breast cancers.

How Long Does a Breast MRI Take?

A breast MRI typically takes between 30 to 60 minutes, but the entire appointment might last up to an hour and a half. The actual imaging session usually lasts about 30 to 45 minutes. During this time, several sets of images are taken, each lasting a few minutes.

If the doctor needs additional information about the abnormal cells found in the MRI, he or she might take additional images (MR spectroscopy), which could add about 15 minutes to the exam. After the test, patients may be asked to wait while the images are reviewed to determine if more are needed.

Breast MRI Results

After the breast MRI, a radiologist analyzes the images. The radiologist then sends a signed report to the physician who ordered the testing, who then shares the results with the patient.

If the MRI shows abnormal results, the cause could be:

• Cysts
• Leaking or ruptured implants
• Abnormal noncancerous tissue
• Scar tissue
• Breast cancer

The patient’s health care provider will answer any questions or concerns about the specific results.

In some cases, the doctor may recommend a follow-up exam. This might be needed to obtain more detailed images or to monitor changes over time. Follow-up exams may also help determine if a treatment is working or if changes are required.

Benefits, Risks and Limitations

A breast MRI offers several benefits, but there are also risks and limitations to consider. One of the main advantages is that it is a noninvasive imaging technique that does not use radiation. It is particularly helpful for detecting and staging breast cancer when tests such as mammograms or ultrasounds are not enough.

MRI is also beneficial for women with dense breast tissue or breast implants, as these may be hard to image with traditional methods. Additionally, the contrast material used in MRI is less likely to cause allergic reactions compared to the dyes used in other scans.

There are, however, some risks. While the strong magnetic field is not harmful, it might affect medical implants and devices. There is also a very small risk of an allergic reaction to the contrast material, and in rare cases, patients who already have severe kidney disease might develop further kidney problems.

There are also some limitations to consider. The MRI test may be more expensive and take longer than other imaging exams. It may be difficult for patients to stay completely still during the procedure, which is necessary for clear images. MRIs also sometimes produce false-positive results, leading to additional tests or biopsies.