What is Breast MRI?

Breast MRI is sometimes recommended as an additional diagnostic tool after a woman has already undergone a mammogram. MRI (otherwise known as "magnetic resonance imaging") is a very sensitive type of imaging that provides a more detailed view of the area being scanned. If a lump or mass was found on mammography, breast MRI can help the doctor determine whether it is likely cancerous. If a cancer is found, MRI can also be used to help determine how far the cancer has spread. Breast MRI is also sometimes used as a screening tool for women who are at high risk for developing breast cancer, or women with breast implants.

Because MRI is a very sensitive screening tool, however, it can also lead to false positive results, which can increase the number of unecessary breast biopsies perfomed. Breast MRI is also quite costly. Therefore, mammography remains the primary screening tool used for the detection of breast cancer.

Technologist with MRI scanner
	Photo of breast MRI

What can I expect during a breast MRI scan?

• Clothing and Other Accessories
  You will be asked to undress from the waist up and will be given a hospital gown to wear. If you have on pants that do not have any metal fastenings, such as snaps, zippers or hooks, you may be able to keep them on during the scan; otherwise, you'll be given a pair of hospital pants to wear. Because they can interfere with the magnetic field, you cannot enter the MRI unit with any metal or electronic items. Some of these items include:
  
  
  • jewelry and watches
  • hair accessories with metal pieces, such as hairpins and barettes
  • clothing with metal fastenings, belt buckles
  • removeable dental work
  • hearing aids
  • credit cards, pens, loose change

Tell your physician or technologist if you have any implanted devices, such as:

• cochlear implants
• pacemakers
• metal pins, surgical staples, screws or plates
• artificial limbs, joints or heart valves
• intrauterine devices (IUDs)
• aneurysm clips or stents
  
  
• Administration of Contrast Solution (sometimes referred to as "dye")
  Before you begin your scan, the technologist will start an IV of contrast solution. Contrast is a dye that makes the internal structures of the body more visible on a scan. In rare instances, a patient may experience an allergic reaction to the contrast, and some patients may experience nausea or pain at the injection site.
  
  
• Scanning
  You will lie face down on your stomach on the examination table. The examination table has two openings in it for each breast to hang down into. The technologist will help to position you as comfortably as possible with pillows and other props. Because the MRI machine makes somewhat loud humming, clicking and banging noises, you will be given earplugs to wear. The technologist will step into an adjacent room where the controls for the MRI machine are located, but they will still be able to hear and see you. The examination table will then slide into the tube. You will be asked to remain still while the MRI machine takes a series of images. The total examination time usually takes about 40 minutes.

What should I do to prepare for a breast MRI?

Wear loose comfortable clothing, and leave jewelry, watches or other metal accessories at home.

What if I am claustrophobic?

Some people with claustrophobia have difficulties with MRI scans. Notify your doctor if you have any concerns about claustrophobia before your examination. Your doctor can prescribe a mild sedative or discuss other possible alternatives with you.

Are breast MRI examinations safe?

Breast MRI examinations are considered very safe. MRI uses a large, powerful magnet, radio waves and a computer to provide detailed images of internal structures. Unlike some other types of scans, such as CT or x-rays, the patient is not exposed to radiation. There is a slight risk of an allergic reaction to the contrast, so let the technician know if you experience any itching or swelling during the exam. Another side effect that can occur is nephrogenic systemic fibrosis, which happens in rare instances when certain types of contrast are used in patients with kidney disease. If you have questions or concerns, please discuss them with your doctor or radiology technologist prior to the exam.

When will I get my results?

Once the technologist has obtained all the images needed, those images will then be sent to one of our staff radiologists. The radiologist will review the scan on a computer and send the results to your physician. Your physician will then discuss the results with you.

For more information about breast cancer and breast imaging, please visit the American Cancer Society's web page at http://www.cancer.org.