Breast MRI

A breast MRI does not replace mammography or ultrasound imaging. However, it is an additional tool that has many important uses, including:

• Screening women at high risk for breast cancer.

• Determining the extent of cancer after a new diagnosis by finding:

  • How large the cancer is and if it involves the underlying muscle.

  • If there are other cancers in the same breast and if there is an unsuspected cancer in the opposite breast.

  • If there are any abnormally large lymph nodes in the armpit, which can be a sign that the cancer has spread.

• Evaluating hard-to-assess abnormalities seen on a mammogram.

• Evaluating areas of past lumpectomy surgeries following breast cancer treatment.

• Assessing chemotherapy treatment results in patients receiving neoadjuvant chemotherapy or hormone therapy.

You will be asked to lie face down on a platform specially designed for the procedure. The platform has openings to accommodate your breasts and allow them to be imaged with minimal compression. It is important to remain very still throughout the exam. This is best accomplished by being comfortable and relaxed.

If a breast MRI is being performed to evaluate a possible ruptured breast implant, you will not be given contrast material. If the exam is being performed for any other reason, you will receive contrast material injected through an IV. An MRI of the breast without contrast material won’t work for identifying breast cancers.

You will be moved into the magnet of the MRI unit, and the radiologist and technologist will leave the room while the MRI exam is performed. When the exam is complete, you may be asked to wait until the technologist or radiologist checks the images in case additional images are needed.

The imaging session lasts between 30 minutes and one hour, and the total exam is usually completed within 90 minutes.

A breast MRI is more expensive than a mammogram. Most insurance that pays for mammograms will likely pay for an MRI, but it is a good idea to check first with your insurance company.

On the day of your breast MRI: 

• You will be asked to remove your bra and top and wear a gown during the exam. You may keep your own bottoms on, but they should be loose-fitting with no metal fasteners. 

• Your MRI exam may require an injection of contrast material. Tell your radiologist or technologist if you have allergies of any kind. 

• Tell your radiologist if you have any serious health problems, or if you have recently had surgery. 

• Do not wear metal of any kind in the exam room. This includes jewelry, hairpins and removable dental work.
  

In most cases, an MRI exam is safe for patients with metal implants. However, people with some implants can’t be scanned and should not enter the MRI scanning area unless explicitly instructed by a radiologist or technologist who is aware of the presence of the following: 

• Internal defibrillator or pacemaker. 

• Cochlear implant. 

• Some types of clips used on brain aneurysms. 

• Some types of metal coils placed within blood vessels.

You should tell the technologist if you have medical or electronic devices in your body, because they may interfere with the exam or potentially pose a risk, depending on their nature and the strength of the MRI magnet. You should notify the technologist or radiologist of any shrapnel, bullets or other pieces of metal in your body.

Fasting before a breast MRI with contrast material:

You may be asked to fast for four hours before your MRI with contrast. This means no food or drink, not even water. Fasting helps to ensure that you have an empty stomach during the exam. If you are pregnant, please let your technologist know so they can provide you with special instructions.

Board-certified radiologists who specialize in breast imaging will interpret your breast MRI results. You can expect your results within a week after your exam. You will receive a telephone call if additional imaging is required to evaluate a possible abnormality. A report will also be sent to your referring doctor, who will share the results with you.

Don’t be alarmed if you are asked to come back for additional imaging. Being called back for more testing does not mean that you have cancer. In fact, less than 1% of women who are called back for more tests are found to have breast cancer. Being called back occurs fairly often and usually just means an additional image or ultrasound needs to be done to look at an area more clearly.

• MRI is a noninvasive imaging technique that doesn’t involve exposure to radiation.

• MRI has proven valuable in diagnosing a broad range of conditions, including detecting and staging breast cancer, particularly when other imaging studies don’t provide clear enough answers.

• MRI helps discover abnormalities that may not be visible with other imaging methods.

• MRI, as an addition to mammography, can be useful in evaluating women at high risk for developing breast cancer.

The MRI exam poses almost no risk to the average patient when appropriate safety guidelines are followed.

• Although the magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems during an MRI exam.

• Manufacturers of IV contrast indicate that mothers should not breastfeed their babies for 24-48 hours after contrast is given.

• There are dangers associated with injection of high doses of contrast material in patients with poor kidney function.

• High-quality images can only happen if you are able to remain perfectly still while the images are being recorded. If you are anxious, confused or in severe pain, you may find it difficult to lie still during imaging. 

• Some people may not fit into the opening of certain types of MRI machines. 

• The presence of an implant or other metallic object sometimes makes it difficult to obtain clear images. Patient movement can have the same effect. 

• Pregnant women are not advised to have an MRI exam unless medically necessary. 

• MRI is typically more expensive and takes longer than other imaging exams. 

• Sometimes a noncancerous piece of tissue in the breast can look like cancer. When it is possible, other testing like an ultrasound or biopsy may be needed.