MRI to Screen for Breast Cancer? Clearing Up the Confusion
Tuesday, July 26, 2005
Magnetic resonance imaging (MRI) is an important diagnostic tool in health care today. An MRI scanner uses powerful magnets and radio waves to take very detailed “pictures” of the organs and structures inside the body. It can detect tissue damage or disease such as infection, inflammation, or tumors.
In the last few years, stories have appeared in the news media about the use of MRI as a screening tool for breast cancer, and some health care facilities promote breast MRI in their advertising. These messages, in turn, have prompted some women to consider an MRI exam in place of or in addition to a regular mammogram. We would like to explain the role of MRI in the diagnosis and treatment of breast cancer, and clear up any confusion.
At this time, MRI is not considered a primary screening tool for breast cancer for women who have no sign of the disease, such as a lump. However, MRI can be useful in certain situations, as described below.
It’s important to recognize that standard procedures (protocols) for breast MRI do not yet exist in this country. There are different types of MRI scanners, and different methods of imaging the breast. Studies are underway to establish consistent protocols for the best breast MRI.
General guidelines for recommending breast MRI currently include:
- In certain situations, MRI is a useful tool for investigating breast masses first detected with mammography, a physical exam, or other imaging exams.
- Breast MRI may be performed for high-risk women, such as those with a family history or past occurrence of breast cancer. MRI can find some of the smallest, early breast cancers when the likelihood for successful treatment is greatest.
- For women who have been diagnosed with breast cancer, MRI can play a role in determining the stage of breast cancer (how far cancer has spread) to help develop a treatment plan.
- MRI may be used before, during, and/or after chemotherapy to evaluate the response to treatment and the extent of remaining disease before surgical treatment.
- MRI can provide an image of a suspicious area for women who have breast implants (including breast tissue obscured by the implant on a mammogram), and to identify a breast implant rupture.
- MRI can help to detect a recurrence of breast cancer after a lumpectomy (surgical removal of a cancerous tumor) in women who have scarring from their surgery. A scar and a recurrence of cancer can look the same on other imaging exams.
- MRI is useful for imaging women with especially dense breast tissue. Younger women tend to have dense breast tissue, which can decrease the effectiveness of mammography. MRI is effective in women with dense breasts.
- Other individual situations in which a breast MRI may be recommended.
While MRI can detect some cancers that are not seen on mammography or ultrasound, it has some limitations. These include:
- MRI cannot always distinguish between cancerous and non-cancerous tumors or conditions that may result in false-positive results. A false-positive result can lead to more tests, such as biopsies, and unnecessary anxiety.
- MRI cannot image calcifications (tiny calcium deposits are often associated with early-stage breast cancers.) Mammography can reliably image calcifications.
- MRI is expensive and may not be widely available.
- Some patients who are claustrophobic may not tolerate an MRI test.
- MRI requires the use of a contrast agent, a substance that makes tissue more visible during the scan. This requires an intravenous injection; in rare cases, a person may not tolerate the contrast agent.
- MRI is more time-consuming than mammography and requires patients to remain motionless.
In summary, breast MRI is an evolving technology and should not replace regular visits to your physician, breast-self exams, and regular mammograms. Talk to your physician about the most appropriate screening method for you. Your best line of defense for detecting breast cancer is to follow the recommended schedule for mammograms and physician visits, and conduct monthly breast self-exams.
The multidisciplinary teams at Columbia St. Mary’s Breast Health Centers offer care for women in a supportive and comfortable setting. Experienced staff members use the latest technology for breast imaging and related services. The staff includes board certified radiologists with special interest and expertise in breast imaging, registered radiology technologists with special training and certification in mammography, and breast health clinicians who specialize in cancer care.
American Cancer Society Guidelines for Mammography
- Breast self-examination is an option for women starting in their 20s. Women should report any breast changes to their health professional right away.
- Women in their 20s and 30s should have a clinical breast examination as part of a regular exam by a health professional, preferably every three years.
- Women age 40 and above should have an annual screening mammogram, and should continue to do so for as long as they are in good health.
- Women at increased risk should talk with their doctor about the benefits and limitations of starting mammograms when they are younger, having additional tests, or having more frequent exams.
Dr. Thomas Berns, radiologist, and Dr. Scott Tannehill, radiation oncologist, are on staff at Columbia St. Mary’s. For more information, call the Van Dyke Haebler Center for Women’s Imaging at 414-961-4141