Breast MRI

Magnetic Resonance Imaging (MRI) of the breasts, or breasts MRI, is a test that is used in the detection of breast cancer and other abnormalities of the breast.

A breast MRI captures multiple images of your breasts. The images are combined using a computer to generate detailed pictures.

Breast MRI usually is performed after you have a biopsy that for cancer, and your doctor needs more information about the extent of the disease.

In certain circumstances, such as for women with a high risk of breast cancer, breast MRI may be used with mammograms as a screening tool for detecting breast cancer.

Your doctor may recommend a breast MRI for the following reasons: 

• If you have a breast cancer diagnosis and your doctor want to determine the extent of the breast cancer.
• If you have a suspected leak or rupture of a breast implant.
• If you are at a higher risk of breast cancer, defined as a lifetime risk of 20 to 25 percent or greater, as calculated by risk tools that take your family history and other factors into consideration.
• If you have a strong family history of breast cancer or ovarian cancer. You have a very dense breast tissue, and the mammogram did not detect a prior breast cancer.
• If you have a history of precancerous breast changes, such as atypical hyperplasia or lobular carcinoma in situ, a strong family history of breast cancer and dense breast tissue.
• If you are not sure whether you are considered high risk, ask your doctor to aid you in determining your personal risk estimate.

Breast MRI is most often used to screen for breast cancer in women thought to have a high risk of the disease. Breast MRI also may be used to assess the extent of breast cancer.

A referral to a breast clinic breast health specialist may help you understand your risks and your screening options.

A breast MRI is a safe procedure that does not expose you to any amount of radiation.

But as with other tests, a breast MRI has the following risks: 

• A risk of false-positive results. A breast MRI may identify suspicious areas that, after further evaluation, turn out to be benign. These results are called “false-positives".
• A risk of reaction to the contrast dye used. A breast MRI involves the injection of a dye to make images easier to analyse. This dye, in some cases, can cause an allergic reaction and lead to serious complications for people with kidney problems.

To prepare for a breast MRI, your doctor can make the following recommendations:

• Schedule your MRI for the beginning of your menstrual cycle. If you're premenopausal, the MRI facility may prefer to schedule your MRI at a certain point during your menstrual cycle, around days seven to 14. Let the facility know where you are in your cycle so that optimal timing for the breast MRI can be arranged.
• Tell your doctor about any allergies you have. Most MRI procedures use a dye to make the images easier to interpret. The dye is usually given through a vein in your arm. Tell your doctor about any allergies to avoid complications with the dye.
• Tell your doctor if you have kidney problems. A dye commonly used to enhance MRI images called gadolinium can cause serious complications in people with kidney problems. Tell your doctor if you have a history of kidney problems.
• Tell your doctor if you're pregnant. MRI generally isn't recommended for women who are pregnant.
• Tell your doctor if you're nursing. If you're nursing, your doctor may recommend that you stop for two days after your MRI. The American College of Radiology states that the risk to the baby from the contrast dye is extremely low. However, if you're concerned, stop breastfeeding for 12 to 24 hours after the MRI, which will give your body time to eliminate the contrast dye. You may pump and discard your milk during this period. You can pump and store milk before the procedure to feed your baby.
• Don't wear anything metallic during the MRI. Metallic objects, such as necklaces, hairpins, and watches, can be damaged during an MRI. Leave metallic objects at home or remove them before your MRI. Tell your doctor about implanted medical devices. If you have an implanted medical device, such as a pacemaker, defibrillator, implanted drug port or artificial joint, tell your doctor before your MRI.

Here’s what you can expect before, during, and after your Breast MRI procedure.

When you arrive for your appointment, a member of your health care team will offer you a gown and a robe. You will receive instructions on removing clothes and jewellery.

If you have trouble being in a small, confined space, tell your doctor before your breast MRI. You may be given a mild sedative.

A contrast agent (dye) may be injected through an intravenous (IV) line in your arm to enhance the appearance of tissues or blood vessels on the MRI pictures. The MRI machine comprises a central opening.

During the breast MRI, you lie face down on a padded scanning table. Your breasts fit into a hollow depression in the table. This depression contains coils that detect magnetic signals from the MRI machine. The entire table then slides into the opening of the machine.

The MRI machine creates a magnetic field around you, and radio waves, waves but you may hear loud tapping and thumping sounds coming from inside the machine. Because of this, you may be given earplugs to wear.

During the test, the technologist monitors you from another room. You can speak to the technologist through a microphone. You will be instructed to breathe normally but to lie as still as possible.

The breast MRI appointment may take 30 minutes to one hour.

A specialized doctor in imaging techniques (radiologist) reviews the results from your breast MRI, and a member of your health care team will contact you to discuss your results.