THE WOMEN'S CENTER
Breast MRI
About
Magnetic resonance imaging (MRI) is a non-invasive way of viewing organs, soft tissues, bone and other internal body structures without the use of x-rays. MRI uses a magnetic field and radio waves together with a computer to create cross-sectional, three-dimensional pictures of the head and body. Detailed MR images allow physicians to better evaluate parts of the body for conditions that may not be visible with other imaging methods (such as x-ray, ultrasound, or computed tomography (CT) scan). MRI has proven very valuable in diagnosing a broad range of conditions, including cancer, heart and vascular disease, stroke and musculoskeletal disorders.
MRI of the breast is not a replacement for mammography or ultrasound imaging but rather is a supplemental tool for detecting and staging breast cancer and other breast abnormalities.
Medical studies are currently being conducted to determine whether MRI and other imaging methods can contribute to the early detection of, and prevention of deaths from, breast cancer. Recent research has demonstrated that MRI can detect some small breast lesions sometimes missed by mammography. MRI can also help detect breast cancer in women with breast implants and younger women with dense breast tissue—both of which are difficult to image using traditional mammography.
What To Expect
You will be positioned face down on the moveable bed with your breasts hanging into the cushioned openings. The bed will then be moved into the magnet of the MRI unit.
The technologist will leave the room while the MRI examination is performed. You will be asked to lie still while the machine acquires the images. Imaging is done in sequences, each lasting between one and fifteen minutes. In between sequences, you will be able to relax. You will know when images are being recorded because you will hear tapping or thumping sounds when the coils that create the magnetic field are turned on.
After an initial series of scans, the contrast material is injected into the intravenous line. Additional series of images are taken following the injection.
When your exam is completed, you will wait a short time on the table while the images are evaluated to ensure no additional images are needed. Your intravenous line will be removed.
The imaging session lasts between 30 minutes and one hour and the total exam will take approximately an hour and a half.
Patient Preparation
Prior to your exam, you may continue to take your usual medications, unless you are told otherwise. You may be given a hospital gown to wear during the exam, or you may be allowed to wear your own clothing if it is loose-fitting and has no metal fasteners. Jewelry and other accessories should be left at home if possible, or removed prior to the MRI scan. Metal and electronic objects can interfere with the MRI's magnetic field and are not allowed in the exam room.
These items include:
Jewelry, watches, credit cards and hearing aids, all of which can be damaged.
Pins, hairpins, metal zippers and similar metallic items, which can distort MRI images. Removable dental work. Pens, pocketknives and eyeglasses. In most cases, an MRI exam is safe for patients with metal implants, except for a few types.
Tell the technologist if you have medical or electronic devices in your body, such as:
Artificial heart valves.
Implanted drug infusion ports.
Implanted electronic devices.
Artificial limbs or metallic joint prostheses.
Implanted nerve stimulators.
Metal pins, screws, plates or surgical staples.
In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of another imaging procedure. If there is any question, an x-ray may be taken to detect the presence of any metal objects. Sheet metal workers and others who might have metal objects such as shrapnel in their bodies may also require an x-ray prior to an MRI. Dyes used in tattoos may contain iron and could heat up during MRI, but this is rarely a problem.
People with the following implants cannot be scanned and should not enter the MRI area:
Cardiac pacemakers.
Defibrillators.
A cochlear (ear) implant.
Common Uses for the Test
MRI is used to:
Evaluate abnormalities detected by mammography.
Identify early breast cancer not detected through other means, especially in women with dense breast tissue and those at high risk for the disease.
Screen for cancer in women who have implants or scar tissue that might jeopardize an accurate result from a mammogram.
Determine the integrity of breast implants.
Distinguish between scar tissue and recurrent tumors.
Assess multiple tumor locations.
Check the progress of chemotherapy.
Look for multiple tumors prior to breast conservation surgery.
Determine whether cancer detected by mammography or ultrasound has spread further in the breast or into the chest wall.
Determine how much cancer has spread beyond the surgical site after a breast biopsy or lumpectomy.
Provide additional information on a diseased breast to make treatment decisions.
Without contrast material, an MRI of the breast can show:
Breast tissue density,
Cysts,
Enlarged ducts,
Hematomas,
Leaking or ruptured breast implants.
By comparing breast images taken before and after contrast material injection, an MRI exam can determine:
If there are breast abnormalities.
Whether an abnormality looks benign (non-cancerous) or malignant (cancerous).
The size and location of any abnormality that looks malignant.
The presence of enlarged lymph nodes.
Risks and Benefits
Benefits:
MRI has been shown to detect small breast lesions that are sometimes missed by mammography.
MRI can successfully image the dense breast common in younger women, as well as breast implants.
MRI contrast material is less likely to produce an allergic reaction than the iodine-based materials used for conventional x-rays and CT scanning.
MRI is a non-invasive imaging technique that does not require exposure to radiation.
MRI provides more clear and detailed images of the soft-tissue structures of the body than other imaging methods. The detail makes MRI an invaluable tool in early diagnosis and evaluation of tumors.
Risks:
The MRI examination poses no risk to the average patient when appropriate safety guidelines are followed.
An undetected metal implant may be affected by the strong magnetic field.
There is a very slight risk of an allergic reaction if contrast material is injected. Such reactions usually are mild and easily controlled by medication. There also is a very small risk of skin infection at the site of injection.
If sedation is used, there are risks of excessive sedation. The technologist monitors the patient's vital signs to minimize this risk.
