Breast MRI
What is Breast MRI?
Breast MRI (Magnetic Resonance Imaging) uses radio waves to look specifically at the breast. It is a non-invasive procedure that doctors can use to determine what the inside of a breast looks like without having to do surgery or flatten the breast as in a mammogram. Each Breast MRI produces hundreds of cross-sectional images of the breast in all three directions, which are then read by our Radiologist. Breast MRI is an evolving technology and should not replace standard screening and diagnostic procedures, such as clinical and self exams, mammogram, fine needle aspiration or biopsy.
What is the difference between Breast MRI and Mammography?
Normal mammograms use x-rays to generate images of the breast tissue to search for cancer. MRI, on the other hand, uses radio waves. The ability to identify a mass in the breast requires that the mass be contrasted from normal tissue. With MRI, the contrast between soft tissues in the breast is 10 to 100 times greater than that obtained with x-rays. MRI of the breast does require intravenous injection of a contrast agent, which helps highlight breast abnormalities.
Is there a disadvantage to breast MRI?
Breast MRI doesn't detect certain types of very small calcifications, which on a mammogram can be an early indication of cancer. Instead, breast MRI uses different cancer markers, including the blood flow of the tumor, as well as the size and appearance of the tumor.
How does it work?
The patient lies on her stomach with both breasts hanging freely into a cushioned recess containing the signal receiver known as the breast coil. The entire bed on which she is lying moves into the MRI machine where the images are taken.
Why would you need this exam?
In recent years Breast MRI has been used to detect cancer in certain types of high-risk women and as an optional exam for the early detection of breast cancer when mammography and clinical exams have not clearly shown the presence of cancer.
The American Cancer Society now recommends that women at high risk for breast cancer have an annual breast MRI exam in addition to mammography. This includes the following categories:
- Young women with very dense breasts.
- Women that are known to carry mutations of the BRCA1/BRCA2 breast cancer genes.
- Women who have had chest wall radiation treatment for cancers such as Lymphoma at an early age.
- Women that have been diagnosed with breast cancer to evaluate the extent of the disease prior to surgery and to look for cancer in the other breast that may have gone undetected in a mammogram.
- Women with breast implants.
Your doctor will discuss with you whether Breast MRI is the appropriate choice for your particular situation. If you wish to learn more about genetic testing to determine your risk for breast cancer, Redwood Regional Medical Group offers specialized cancer risk assessment, counseling and genetic testing through its Fountaingrove Campus in Santa Rosa. Oncology Nurse Practitioner, Theresa Mortensen, RN-C, MSN, OCN, leads the Cancer Risk and Genetics Program and serves as the Hereditary Cancer Risk Assessment Counselor. She sees patients for consultations in her office at 3555 Round Barn Circle and can be reached at 707-528-1050.
Pre-exam instructions for a MRI
We recommend that you wear comfortable clothes without metal snaps or buttons. Please leave all personal items at home. If you require any sedation for the MRI, you will need a prescription from your referring physician. If sedation is given, you will need to have someone drive you to and from your appointment.
The day of your exam
On the day of your exam, please arrive 15 minutes prior to your appointment time to check in and complete the necessary forms. Be sure to have your insurance information ready and available. Once you have registered, our technologist will escort you to an exam room. You will change into the hospital clothes provided and we will have an IV line inserted into a vein in your hand or arm if your exam requires contrast. It will be necessary to have a blood test prior to the exam to ensure your kidneys are properly working to filter the contrast out of your body. This test can be done just prior to the MRI exam.
The procedure involves your being placed on the MRI table. Your breasts will be placed in depressions in the scanning table that house the equipment used to detect the magnetic resonance signal call breast coils. You will be asked to remain quiet and breathe normally while the table moves inside the magnet. It is very important that you stay still while the pictures are being taken.
After the first series of images are complete, you will receive an injection into a vein of about 15 cc (3 tablespoons) of Gadolinium, a non-radioactive contrast agent that improves the visibility of some tumors in MRI scans. This injection will be performed by our MRI technologist. An additional series of images will be taken after the injection. You should allow about an hour from start to finish, with the imaging session taking approximately 30 minutes.
After your exam
Once the entire exam is over, the table will move out of the magnet and the technologist will help you off the table and remove the IV. Once you have changed out of the gown, you are then free to resume your daily activities.
Your scan will be evaluated by our Radiologists, with a report sent promptly to your referring physician who will be able to review the results with you.
MRI side-effects
Since MRI uses radio waves to create the images and no radioactivity is involved, the technique is believed to have no health hazards in general.