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When would I need a breast MRI exam?

Women's Care
Aug 20, 2019

St. Joseph’s/Candler Breast Cancer Surgeon Dr. Susan Mahany explains MRI’s role in women’s breast health

There are many imaging devices that we may need in our lifetime. X-rays for broken bones. Ultrasounds during pregnancy.

Dr. Susan Mahany, Telfair Breast SurgeonOne such device that some women may need is an MRI to examine their breasts. A breast MRI (magnetic resonance imaging) is a non-invasive exam that uses radio waves, a magnetic field and a computer to create detailed pictures inside the breasts.

MRI is another diagnostic tool, in addition to mammography and ultrasound, to view the breasts looking for abnormalities. One is not particularly better than the other, and oftentimes, the three scans are used in combination to get the best results possible, says Dr. Susan Mahany, breast cancer surgeon and medical director of Telfair Breast Surgery at St. Joseph’s/Candler.

“It’s like comparing apples and oranges, comparing a mammogram to a MRI. They will both show you breast cancer. They just show it in different ways,” Dr. Mahany says.

Related Article: Life-saving technology: Schedule your mammogram today

A MRI machine uses strong magnets to make detailed, cross-sectional pictures of the body. MRI scans take images from many angles, as if someone were looking at a slice of the body from the front, side and above. MRI creates pictures of soft tissue parts of the body that are sometimes hard to see using other imaging tests.

When would I need a breast MRI exam?

Not every woman requires a MRI breast exam. It’s a good imaging tool to use when:

1. A woman has an abnormality, or lump, detected during a self-breast exam or doctor’s physical but a negative mammogram and a negative ultrasound.

2. A woman, up to 85 years old, has a calculated lifetime risk of at least 20 percent of genetically developing breast cancer, then a MRI scan alternates every six months with a mammogram.

Related Article: Should I have my genes tested if my mother or grandmother had breast or ovarian cancer

3. A woman has Class D breast density, which is 75 percent fibroglandular tissue, and about 10 percent of the female population. Some women with Class C breast density, which is about 50 percent, may get a baseline MRI, depending on insurance coverage.

Related Article: Breast cancer risk factor: Do you have dense breasts?

4. A woman is diagnosed with invasive lobular breast cancer. An MRI may provide a more accurate measurement of the tumor than mammogram or ultrasound.

Related Article: Understanding staging and types of breast cancer 

5. A woman who is getting neoadjuvant chemotherapy, which is chemotherapy before surgery. An MRI taken before and after neoadjuvant chemo will help a surgeon like Dr. Mahany see how much the tumor has shrunk.

6. A woman with breast implants that may have ruptured or are suspected of leaking.

“Patients always want to know, ‘Why do you want to do this?’” Dr. Mahany says. “MRI is just a different way of looking at breast tissue. It’s always better to have the maximum amount of information.”

Are MRIs safe?

Jonathan NelsonOne question that both Dr. Mahany and Candler Hospital MRI Technologist Jonathan Nelson are often asked is about safety. Unlike X-rays and CT scans, MRIs do not use radiation. However, they do require contrast, with the exception of examining breast implants.

Contrast is an agent that improves the visibility of the anatomy for clearer images, Nelson explains. Contrast is safe, but some patients may experience nausea following a scan, Nelson says. Additionally, patients with chronic renal insufficiency may want to limit exposure to contrast due to a small chance of damage to the kidneys.

What to expect during a breast MRI exam?

Claustrophobia is another big concern Nelson sees among patients getting an MRI.

The good news about a breast MRI exam is that patients are flat on their stomach. Their head is facing down in a pillowed-hole and the arms are over the head, Nelson describes. Looking down as opposed to staring into the MRI tunnel may help claustrophobic patients.

A bar will be placed underneath the breasts to keep them in relatively the same position, which Dr. Mahany says some patients may find uncomfortable.

The scan itself only takes about 25 to 30 minutes. Patients can talk with the technologists if they need to and music can be piped into the room.

Related Article: What to expect during a MRI

It’s important to remember that every woman is different. Talk to your physician about the best options for your breast health.

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