Most Common Uses for a Breast MRI
The most common use for breast MRI is high risk screening, which is indicated annually to supplement a mammogram for women who have a 20% or greater lifetime risk of breast cancer.
The 20% or greater lifetime risk is determined by one of multiple risk models. They are found online — for example, on the National Cancer Institute website.
Recent literature supports the use of screening MRI for women with a personal history of breast cancer and dense breast tissue, as well as when a woman has a recent diagnosis of breast cancer.
Of the breast imaging modalities, MRIs have been shown to demonstrate the most accurate extent of disease of any of the breast imaging modalities. Our breast imaging specialists also look at the contralateral breast when there is a new breast cancer diagnosis. The data demonstrates that 3% to 5% of women will have asynchronous contralateral breast cancer, which is critical to diagnose at the time of breast cancer treatment.
The breast MRI can also identify the extent of the cancer that has been biopsied by determining if cancer is in more than one quadrant, and if the chest wall or the skin and nipple are involved. The MRI can help breast surgeons determine whether a lumpectomy or mastectomy should be planned.
Identifying clinical symptoms
Nipple discharge that is either clear or bloody, like from papilloma or in situ and invasive breast cancers, is first evaluated with a mammogram and ultrasound. If these modalities do not find a cause for the nipple discharge, MRI can be used to evaluate further.
Visualizing unknown breast cancer in the lymph nodes of the axilla
Occasionally, breast cancer is found in lymph nodes in the axilla before a cancer in the breast has been identified. If mammography and ultrasound are not able to identify the primary malignancy, breast MRI is performed. Breast MRIs can identify small cancers that have led to the metastatic disease in the axilla, aiding treatment planning.
When a patient has new nipple inversion, mammography and ultrasound are first performed to identify a suspicious underlying cause. When no cause is identified, breast MRI can be used. MRI can often demonstrate where to biopsy and the next steps.
Difficult imaging problem
Occasionally, when a definitive lesion cannot be identified by mammography or ultrasound, a breast MRI can help sort out the findings that are confusing on previous imaging.
Frequently Asked Questions
High risk defines when radiologists use breast MRIs. Several risk models use modeling techniques to predict risk for breast cancer. Each of these risk models has benefits and drawbacks, with factors such as age, race, BMI, parity, age at first menstrual cycle, and personal and family history of breast cancer.
In addition, women with BRCA1 or BRCA2 gene mutations, untested women who have a first degree family member with a known BRCA1 or BRCA2 mutation, and women with a history of chest radiation between the ages of 10 and 30 are considered high risk and are recommended for annual screening MRI.
Breast MRI should always be used as a supplement to mammography. These two modalities can visualize breast cancers in different ways, and together provide the most information to the radiologist. Specifically, breast MRI is not always able to identify the earliest form of breast cancer: ductal carcinoma in situ.
High risk women should have both an annual mammogram and an annual MRI. These can be done on the same date or six months apart, at the patient’s or provider’s discretion. It is also important to time the MRI to occur between days seven and 14 of the menstrual cycle to best visualize the breast tissue.
It can be very complex to put a patient’s family and personal health history together to determine what is relevant. Johns Hopkins Medicine’s Breast and Ovarian Surveillance Service, also known as the BOSS clinic, assists patients and referring physicians. BOSS clinic appointments are comprehensive single visits that provide patients with a care plan and help them understand their risk, whether they should be tested for BRCA1 or BRCA2 genes, and how they should most effectively screen for breast and ovarian cancer.
A breast MRI can be very useful in determining leakage. It is important to know what type of implant is in place. For example, saline implants don't need an MRI for assessment of rupture or leakage because these implants simply collapse when they rupture, which can be diagnosed on physical examination or mammography.
Much of what is viewed in a breast MRI is the breast tissue parenchyma, and it requires contrast. Regarding implants, contrast material is not needed. Radiologists are looking to see where the silicone is located. The three options are that the silicone is in the implant, outside the implant but in the fibrous capsule that the body makes surrounding the implant, or free in the breast tissue or within a lymph node.
The ruptures are intracapsular (silicone within the fibrous capsule of the implant) or extracapsular (silicone outside the implant capsule and within breast tissue and/or lymph nodes). A breast MRI distinguishes these ruptures very clearly.
Johns Hopkins uses MRI to assess implants due to a change in clinical exam or physical exam, or a patient’s concern. Recent silicone implants, whether for cosmetic or reconstructive purposes, require the patient to agree to undergo MRI to assess implant integrity every three years.
We strongly recommend that women begin screening mammography at the age of 40 and continue annually until their life expectancy is less than five years due to comorbid disease. In the United
States, a woman is diagnosed with breast cancer every three minutes, and 12% of those women are in their 40s. A woman dies of breast cancer in the United States every 13 minutes. Screening and early detection can help us provide better care for breast cancer patients in the United States.