Breast MRI

A breast MRI is used to assess the extent of breast cancer. It's also used to screen for breast cancer in women thought to have a high risk of the disease.

Your health care provider may recommend a breast MRI if:

• You've been diagnosed with breast cancer and your provider wants to determine the extent of the cancer
• You have a suspected leak or rupture of a breast implant
• You're at high risk of breast cancer, defined as a lifetime risk of 20% or greater, as calculated by risk tools that account for your family history and other risk factors
• You have a strong family history of breast cancer or ovarian cancer
• You have very dense breast tissue, and mammograms didn't detect a prior breast cancer
• You have a history of precancerous breast changes — such as atypical hyperplasia or lobular carcinoma in situ — and a strong family history of breast cancer and dense breast tissue
• You have a hereditary breast cancer gene change, such as BRCA1 or BRCA2
• You had radiation treatments to your chest area before age 30

If you're unsure whether you may be at high risk, ask your provider to help you determine your personal risk estimate. A referral to a breast clinic or breast-health specialist may help you better understand your risk and your screening options.

A breast MRI is intended to be used along with a mammogram or other breast-imaging test — not as a replacement for a mammogram. Although it's a sensitive test, a breast MRI can still miss some breast cancers that a mammogram will detect.

A breast MRI is a safe procedure that doesn't expose you to radiation. But as with other tests, a breast MRI has risks, such as:

• False-positive results. A breast MRI may identify suspicious areas that, after further evaluation — such as a breast ultrasound or breast biopsy — turn out to be benign. These results are known as false-positives. A false-positive result may cause unneeded anxiety if you have additional testing, such as a biopsy, to assess the suspicious areas.
• Reaction to the contrast dye used. A breast MRI involves injection of a dye to make the images easier to interpret. This dye can cause allergic reactions and can cause serious complications for people with kidney problems.

To prepare for a breast MRI, you will need to take these steps:

• 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 time during your menstrual cycle, around day three to 14. The first day of your menstrual bleeding is day one of your cycle. Let the facility know where you are in your cycle so that optimal timing for the breast MRI can be scheduled.
• Tell your provider 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. Let your provider know about any allergies to avoid complications with the dye.
• Tell your provider if you have kidney problems. A dye commonly used to enhance MRI images called gadolinium can cause serious complications in people with kidney problems. Let your provider know if you have a history of kidney problems.
• Tell your provider if you're pregnant. An MRI generally isn't recommended for women who are pregnant because of the potential risk of the gadolinium contrast to the baby.
• Tell your provider if you're nursing. If you're nursing, your provider may recommend that you stop for two days after your MRI. The American College of Radiology states that the risk to your baby from the contrast dye is extremely low. However, if you're concerned, stop breast-feeding 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. Before the procedure, you can pump and store milk to feed your baby.
• Don't wear anything metallic during the MRI. Metallic objects, such as jewelry, hairpins and watches, can be damaged during an MRI. Leave metallic objects at home or remove them before your MRI.
• Tell your provider about implanted medical devices. If you have an implanted medical device, such as a pacemaker, defibrillator, implanted drug port or artificial joint, let your provider know before your MRI.