What is Breast MRI?
Breast MRI is a sophisticated technology that uses a computer, magnetic field and radio waves instead of x-rays to produce images of the soft tissues in the body. This non-invasive procedure helps Johnson County Imaging Center’s Radiologists to better evaluate the breast in special circumstances. When used in conjunction with screening and diagnostic mammography, it can provide valuable information for the detection and characterization of breast disease.
If MRI is used, it should be in addition to, not instead of, a screening mammogram. While an MRI is more likely to detect cancer than a mammogram, it may still miss some cancers that a mammogram would detect. MRI also has a higher false positive rate (where the test finds things that turn out to not be cancer), which would result in unneeded biopsies and other tests if performed on a large portion of women.
Breast MRI has been proven to be more sensitive than any other modality in detecting invasive breast cancer. MRI is superior at demonstrating the size and extent of a breast tumor prior to surgery. In addition, it is beneficial for screening patients at particularly high risk for breast cancer due to genetic predisposition or strong family history, diagnosing breast implant rupture, staging breast cancer and planning treatment. MRI also plays an important role in post-surgical and post-radiation follow-up. In March 2007, the American Cancer Society revised the breast cancer early detection guidelines, recommending annual breast MRI screening for women in the following groups:
- have a known BRCA1 or BRCA2 gene mutation
- have a first-degree relative (mother, father, brother, sister or child) with a BRCA1 or BRCA2 gene mutation, and have not had genetic testing themselves
- have a lifetime risk of breast cancer of about 20% to 25% or greater, according to risk assessment tools that are based mainly on a family history that includes both her mother's and father's side
- had radiation therapy to the chest when they were between the ages of 10 and 30 years
- have a genetic disease such as Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome, or have one of these syndromes in a first-degree relatives
Women at moderately increased risk (15% to 20% lifetime risk) should talk with their physicians about the benefits and limitations of adding MRI screening to their yearly mammogram. These patient groups include:
- have a lifetime risk of breast cancer of 15% to 20%, according to risk assessment tools that are based mainly on family history (see below)
- have a personal history of breast cancer, ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), atypical ductal hyperplasia (ADH), or atypical lobular hyperplasia (ALH)
- have extremely dense breasts or unevenly dense breasts when viewed by mammograms
What to expect the day of the Exam
Prepare to arrive 30 minutes before your appointment time. The entire appointment will take 45 minutes to an hour. This exam should be scheduled 7-10 days after the start of your menstrual cycle. Correct timing is important to minimize false positive findings that can occur due to hormonal influence on the breast tissue. If you suffer from minor claustrophobia or anxiety, you may want to ask your physician for a mild sedative. Do not take the sedative until you have signed your paperwork. A Breast MRI does not require your breasts to be compressed, so you should not experience discomfort.
When you arrive you will be asked to complete paperwork regarding your history and symptoms. We will escort you into a private dressing room where you can change into a gown and remove all jewelry, since these items contain metal, which disturbs MRI signals. A female technologist will position you for the scan. During the exam, you will lie on your stomach with your arms up over your head and you will enter the machine head first. Avoid eating a large meal prior to the exam. Most patients receive an injection of contrast material called gadolinium during the exam through an intravenous injection. A small intravenous catheter will be placed in your hand or arm. The injection of contrast material is necessary if the MRI is being performed for the diagnosis of breast cancer. It is sometimes not necessary if the sole intent of the study is to evaluate silicone breast implants. Adverse reactions to gadolinium are rare.
You will be asked to lie very still, relax and breathe normally. The MRI scan will only take 30-45 minutes. There are typically no side effects during or after MRI, so you can resume normal activities as soon as your exam is over. It is very important that any prior breast films (mammograms, ultrasound or MRI) be made available to the radiologist for comparison during the interpretation of your MRI scan. If you have had these at a facility other than Johnson County Imaging please bring them with you on the day of your appointment. If you have any of the items listed below, please call 913.469.8998 so we can make arrangements for you before your appointment. Many of these items are contraindications to having an MRI as they are not compatible with the magnetic field present around all MRI machines.
- Cardiac Pacemaker
- Artificial heart valve prostheses
- Aneurysm clips
- Eye implants or metal ear implants or any metal implants activated electronically, magnetically or mechanically.
- Copper 7 IUD
- Shrapnel or non-removed bullet
- Weight over 350 lbs.
- Any metal puncture(s) or fragment(s) in eye