What is MRI-Guided Breast Biopsy?

MRI-guided breast biopsy is a diagnostic procedure that is used to evaluate suspicious findings detected on a recent MRI exam. After scanning the breast to locate the area in question, tiny samples of breast tissue are removed through a special hollow needle. Samples of this tissue are examined under a microscope to detect the presence of cancer cells. Immediately after an MRI-guided breast biopsy, patients will have an abbreviated follow-up mammogram.

How should I prepare for this exam?

You may eat a light breakfast in the morning before your exam. You may shower or bathe before your procedure. However, please don't use deodorant, lotion, perfume or powder. Wear a comfortable bra and a sweater or top that opens down the front and can be easily put on after the procedure.

Take your usual medications, unless otherwise instructed by your physician. For 7 days before the biopsy DO NOT take products that may increase your risk of bleeding.

Such products include aspirin, ibuprofen, Advil, Motrin, Naprosyn, and supplements like Vitamin E, garlic, glucosamine, chondroitin, flaxseed, fish oil, feverfew, ginger, licorice, St. John's Wort and zinc.

You will be asked to arrive 1 hour early for your exam and check in at the main reception desk. Please bring your health insurance information and any recent mammogram films that you may have.

You may request a prescription from your physician for a medication such as Ativan or Valium to reduce any anxiety you may have about the procedure. However, you must take the medication at the MRI Center only after your intake paperwork has been completed. If you choose to take such medication, you need arrive an additional fifteen minutes earlier. Since such medications may make you drowsy, please arrange to have someone drive you to your follow-up mammogram (see below) and then home.

Please bring with you a list of all your medications, including frequency and dosages for each, and a list of any allergies you may have.

What can I expect during the procedure?

When you arrive, you will be asked to undress and put on a gown that ties in front.

A technologist and a nurse will ask you some questions about your medical history. The radiologist will explain the procedure, answer any questions you may have, and then give you a consent form to read and sign. After completing the consent form you may take any medication your doctor has prescribed.

An intravenous catheter will be placed in your arm for the administration of contrast for the MRI imaging portion of the biopsy.

A technologist will help you to lie face down on the padded MRI table. Your breast will be placed in an opening in the MRI table with the side of your breast supported and stabilized for proper imaging of the site.

MRI images will be taken to precisely locate the site in question.

The MRI exam is painless and takes about 60 minutes. It will be necessary to lie still during the imaging process.

Once the site is identified the radiologist will cleanse your skin with an antiseptic that will feel cool and wet. A local anesthetic will be injected to numb the area. The radiologist will guide a thin, hollow needle into the breast tissue to collect tissue samples. The nurse will be with you during the entire procedure.

Toward the end of the procedure a small titanium clip will be passed through the needle at the biopsy site for future identification of the site by the surgeon, should the biopsy be positive.

You will not be able to feel the clip, and it will not set off metal detectors. If the biopsy is benign, the clip will remain in the breast and does not need to be removed.

The radiologist will remove the needle and pressure will be applied to the insertion site for 5-10 minutes. The nurse will clean your breast and place a dressing over the insertion site.

If you feel discomfort during any part of the procedure, tell the radiologist, nurse or technologist immediately.

What are the risks of the procedure?

The risks of an MRI guided breast biopsy may include: bleeding, bruising, an adverse reaction to medications, and occasionally, failure to obtain enough tissue to reach a diagnosis. The radiologist will review the risks with you and answer any of your questions or concerns before performing the procedure.

What can I expect after the procedure?

Immediately after the biopsy, we will arrange for you to have a 2-view mammogram at a nearby facility to confirm the placement of the clip. (Directions will be provided.)

As long as you feel well you may resume your normal schedule. Avoid any strenuous activity for the next 24 hours. If you have taken anti-anxiety medication you will need to go home and rest.

Keep the biopsy site and dressing dry for 24 hours. After that you may shower. Leave the steri-strip bandages on until they fall off on their own (in about 4-5 days).

To relieve swelling or bruising following the procedure, it is important to apply ice for 20 minutes on, 30 minutes off, several times during the day of the procedure. You may take acetaminophen (Tylenol), but DO NOT take products containing aspirin or ibuprofen (Motrin, Advil, Naprosyn, etc.) for 24 hours, unless otherwise instructed by your doctor. Many women find that a wearing a supportive bra is comfortable after the procedure.

The biopsy site may ooze a little. Applying pressure with your hands directly over the site for about 5 minutes should stop the bleeding. If you notice more than a little bleeding, or if you notice increased redness, pain or swelling, call your doctor or surgeon, or you may call the North Shore Magnetic Imaging Center (978-532-8960) and ask to speak to the nurse.

It is normal to have bruising for about 10 days after this procedure.

Upon discharge you will be given written aftercare instructions.

A nurse from the North Shore Magnetic Imaging Center will call you 24 hours after your procedure to ensure that you tolerated the procedure well.

What about the results of the biopsy?

Usually the results of your biopsy will be available in 2-3 days. The lab will forward the report to your physician, who will discuss the results with you.