Breast MRI
Mammography is the main test used to find breast cancer in women who do not have symptoms and is the only screening test that has been shown to reduce the number of women who die from breast cancer by about 30%. However, breast MRI is the most sensitive method of finding breast cancer, especially in women who are at a very high risk for breast cancer, meaning greater than a 20-25% chance of developing breast cancer in their life. So women at very high risk are recommended to have both a yearly mammogram and breast MRI as part of their annual breast cancer screening. However, because of the high cost, breast MRI is not generally recommended for women who are at normal or moderate risk of breast cancer.
What is the difference between a mammogram and breast MRI?
Mammography and breast MRI use different ways to find breast cancer. Mammography uses X-rays to take a picture of the breast. Cancers are usually seen as either bright dots (of calcium) or as masses that are denser or whiter than the normal breast tissue on a mammogram. However, because both cancers and dense breast tissue are white on a mammogram, some cancers will be hidden, especially in women who have dense breasts.
During a breast MRI, a contrast dye is injected into a vein (also called IV) and magnetic fields and radiowaves are used to make images of the breast. Unlike a mammogram, there is no radiation. Breast cancers usually have increased blood vessels feeding the cancer and therefore will look brighter than the normal breast tissue. Because cancers are not usually hidden by normal breast tissue on MRI, many research studies have shown that breast MRI will find more breast cancers compared to a mammogram. For example, screening mammography finds about 5 cancers per 1000 women screened. If a breast MRI is done in a women with a normal mammogram, an additional 10-15 cancers will be detected on the MRI. Without a doubt, breast MRI is the most sensitive test that we have to detect breast cancer.
What is the cost of a breast MRI?
Even though it finds more breast cancers than regular mammograms, the use of screening MRI has been limited to a small group of women at very high risk for breast cancer because of its cost. A breast MRI can cost several thousands of dollars, compared to several hundred dollars or less for a mammogram. The major national organizations like the American Cancer Society, the National Comprehensive Cancer Network, and the American College of Radiology, among others, recommend extra screening with MRI for women who have greater than a 20-25% lifetime risk of getting breast cancer based on their family history. Most insurance companies follow these national guidelines and will only cover the cost of the MRI in women who are at this high level of risk. Talk to your doctor if you have a strong family history of breast cancer or if you think you may have a breast cancer gene.
This information provided by our experts at The Breast Center, the ONLY facility in Texas to have achieved three major distinctions in the field of breast care.