MRI and Breast Health

Magnetic Resonance Imaging (MRI) is an exciting tool to promote breast health and fight breast cancer.   MRI combines the highest quality pictures of breast tissue with the highest cost of any breast imaging modality.  The best for the most.  Given the wide but somewhat confusing use of breast MRI, it is worth a moment to review this technology.

MRI uses magnetism to create images of tissue. There is no X-ray exposure.  Ions in water and fat change in a high-powered magnetic field.  Differences in tissue ions are detected by applying magnetic pulses.  The pictures are in 3-D and show details of muscle, fat, supportive fibers, blood vessels and glands.  MRI detects breast cancer by highlighting tiny blood vessels that grow in cancer.

The scan is taken in the prone (face down) position over a specialized MRI coil and takes about 45-60 minutes.  Taking a mild sedative (like Xanax) before the test can help the claustrophobia experienced by many patients. Ideally, images should be taken between the 7th and 14th days of the menstrual cycle.

The test requires IV injection of a contrast agent called gadolinium (“gad”). This is not iodine based and allergies are uncommon. MRI contrast is not needed if the goal of the scan is to check a silicone breast prosthesis.  However, allergy to gad and significant kidney disease are contraindications.  Patients with pacemakers, pieces of metal or recent surgical clips can not have MRIs.

MRI is the most sensitive test for detection of breast cancer.  However, there is no evidence that its greater ability to detect small cancers (more then a screening mammogram or ultrasound) results in increased cure rates.  Therefore, as it is 10 times more expensive then mammography ($102- $212 vs. $2,000 – $6,200) and has an increased rate of false positives (sees things which need biopsy but do not turn out to be cancer) it is indicated only in select situations.

Breast MRI is recommended in addition to mammogram as a yearly or semi-yearly screening test in women that have a lifetime risk of breast cancer of 20 percent or more. This generally means women who carry the breast gene (BRCA 1/2) or have a strong family history of breast or ovarian cancer.  Women who have a history of therapeutic chest radiation (such as in treatment of Hodgkin’s Disease) should start getting annual MRIs after age 25.  In addition some experts advise breast MRI when mammograms are difficult to read (i.e. are “dense”).

MRI’s are commonly used to follow up inconclusive changes found on routine screening mammograms.  The MRI can help decide if a biopsy is required or if the abnormality seen on the mammogram is likely to be benign. When needed, MRI can be used to guide a biopsy.

75 percent of women with a new diagnosis of breast cancer have an MRI of both breasts before surgery. The test can detect other breast cancers in the same breast, not felt by exam or not seen on mammogram.  In addition, when a new breast cancer is found, there is an increased chance of breast cancer in the other breast.  The use of MRI in this way is controversial, as there is a significant increase in unnecessary biopsies and mastectomies.  MRI used in this way has not yet been proven to save lives.

Silicone implants can rupture and leak into the breast requiring removal and replacement of the implant.  Breast MRI is quite effective for detecting rupture.  MRI can also be used to differentiate false tumors caused by direct silicon breast injections (not done in many years) verses cancer. MRI cannot evaluate saline implants.

In conclusion, the use of breast MRI should be confined to high-risk situations where clear differences in treatment will be made based on the findings of the scan.  MRI supplements the use of mammograms in breast cancer diagnosis and screening.  This is not a “routine” test, but a special tool to evaluate particular problems.


  • JanetheWriter
    With regard to BRCA mutations, what recommendations/suggestions do you offer to families of breast cancer patients about genetic counseling and testing for these mutations? Thank you.
    • James Salwitz, MD
      As a general statement, if there is a question in a family of possible BRCA mutation, then it is an excellent idea to speak to an Oncologist or Genetic Counselor for guidance. A one hour visit can save lives. The general recommendations are: If there is a family history to suggest a risk for the BRCA mutation (pre-menopausal breast cancer, multiple breast cancers, any male breast cancer, ovarian and breast cancer at any age, Ashenazie Jewish descent) then the starting place is to test someone in the family who has (or had) one of these cancers. Only if that person is positive should other family members be tested. Then everyone who could have inherited the gene (siblings, children, even a young parent) should be tested for that gene. It is normal practice to test each person in series to follow the transmission of the gene through the family. That way if a Mother and Father do not have the gene, then their children do not need to be tested. In Jewish families some experts recommend testing for all 3 common mutations in all family members that could have inherited the gene, not just the detected mutation. Children do not need to be tested until they are 18 - 21. If the family member who had a cancer that might have been related to the BRCA mutation has died without being tested, then the decision is harder. It is reasonable to test children of that person and siblings. Do not forget that a person with the mutation has a 50% chance of giving it to each of to their children, so finding it or not in one person, does not predict their sibling. jcs
  • JanetheWriter
    Thank you for this information. In fact, I'm familiar with much of it because my mother -- unbeknownst to any of us during her lifetime or illness -- was (we surmise) BRCA+. Although her sister also had breast cancer, genetic counseling/testing, as far as we know, was not discussed with her. Only after she died from TNBC did my sister and I (of our own accord) pursue genetic counseling and testing. Indeed, although my sister is negative, I am positive for one of the founder mutations common among Ashkenazi Jews. Thank goodness we took the initiative...
    • James Salwitz, MD
      THanks. While I am certain it was tough to learn that you carry a gene which puts you at risk, it is empowering to have that information to protect yourself. Let me know if there is more information which might be of assistance to you. jcs
      • JanetheWriter
        Thanks. In the last year I had all the prophylactic surgeries and am pleased with my decisions. My mother was a patient of yours, however, so please be reminded that BRCA mutations can be present even in families where BC onset is post-menopausal and neither BC nor OC is rampant -- or even very present at all. A great resource that you may or may not be aware of is FORCE (, a national organization devoted to providing resources and support for BRCA positive individuals and families, as well as others at high risk for breast and ovarian cancer. Thank you again for engaging in this conversation.
        • James Salwitz, MD
          Thanks very much for the link and the reminder. jcs

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