How Breast Magnetic Resonance Imaging (MRI) is Used
UW Health's radiology services in Madison, Wisconsin offer magnetic resonance imaging (MRI), one of the most advanced and rapidly evolving clinical imaging tools available in medicine today.
How Breast Magnetic Resonance Imaging (MRI) is Currently Used
Presently, MRI breast imaging is being used for:
- Staging newly diagnosed or existing cancer so that the proper treatment can be provided. This means measuring the size of the cancer and determining whether there is more than one breast cancer.
- Detecting occult breast cancer when positive axillary lymph nodes are present but the mammogram is negative.
- Distinguishing postoperative scar versus tumor recurrence when there are new changes at a lumpectomy scar.
- Screening in high-risk patients with a breast cancer gene mutation or history of radiation to the chest for the treatment of Hodgkin's disease.
- Monitoring response to neo-adjuvant chemotherapy given before surgery for breast cancer.
- Determining close or positive surgical margins if not found on path.
- Evaluating integrity of breast implants to decide if the implant is ruptured and what type of rupture has occurred.
- Solving issues that could not be satisfactorily resolved by diagnostic mammography or ultrasound.
MRI has previously been proven extremely useful in the evaluation, staging and monitoring of breast cancer and other breast problems. Recently, however, several studies have also demonstrated its ability to detect early breast cancer in high-risk women (screening). This has prompted the American Cancer Society to issue formal guidelines for breast MRI screening of high-risk women in addition to the recommended yearly mammogram.
The following women should undergo yearly breast MRI screening beginning at or around 30 years of age:
- Known carriers of BRCA 1 or BRCA 2 mutations
- First-degree relatives with known BRCA 1 or BRCA 2 mutations
- Clinical lifetime risk estimated at greater than 20 percent using clinical risk estimator (the BRCAPRO model are among the tools suggested)
- Known Cowden's, Li-Fraumeni or Bannayan-Riley-Ruvalcaba syndrome or first-degree affected relative
In women at high genetic or familial risk of breast cancer, MRI has high sensitivity (up to 94 percent) for the detection of breast cancer when used as an adjunct to mammography. This increase in sensitivity may lead to an earlier diagnosis of malignant breast lesions. However, MRI and mammography combined may lead to an increase in false positives, resulting in higher rate of benign biopsies. At this time there are no studies on the differential effect of screening modalities on mortality or long-term outcomes.
Evidence is inconclusive regarding the following situations and DOES NOT YET SUPPORT routine breast MRI screening:
- Clinical lifetime risk estimated at 15 percent to 20 percent using clinical risk estimator
- Previous lobular carcinoma in situ (LCIS), atypical lobular hyperplasia (ALH), atypical ductal hyperplasia (ADH) biopsy results
- Previous history of breast cancer including ductal carcinoma in situ (DCIS)
- Extremely dense mammogram (density 4)