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MRI-Guided Core Biopsy of the Breast

This information describes your magnetic resonance imaging (MRI)-guided core biopsy of the breast procedure.

You are scheduled for a biopsy of your left/right breast that uses an MRI. An MRI uses magnetic fields and radiowaves to detect the size and location of tumors.

Your appointment date is _____________________.

Before Your Procedure

You may not be able to have the MRI-guided core biopsy if you have metal objects in your body. Examples are surgical clips in the brain, a pacemaker, or shrapnel. The metal object or device could shift from its place or malfunction as a result of the strong magnetic field of the scanner. Ask the MRI staff before you go in for your appointment if you are not sure.

If you take a blood thinning medication, you will need to stop taking it before the procedure. Tell the doctor who ordered it that you will be having a biopsy and ask if you need “bridge therapy.”

Stop taking the following 5 days before your procedure:

  • Aspirin and products that have aspirin
  • Vitamin E and multivitamins that have vitamin E
  • All herbal remedies 
  • Warfarin (Coumadin®)
  • Clopidogrel (Plavix®), if you take it by mouth

Stop taking the following 24 hours before your procedure:

  • Low molecular weight heparin by injection
  • Nonsteroidal anti-inflammatory drugs, or NSAIDs (e.g., ibuprofen, Motrin®, Advil®, Aleve®)

Call the Breast Imaging Section the day before your procedure to confirm your appointment and check the time. The number is _____________________.

Your procedure will be done at: __________________________________.

The Day of Your Procedure

  • Shower in the morning.
  • Do not apply any moisturizers, lotions, or talcum powder.
  • Eat your regular meals.
  • Wear comfortable clothing (preferably, a two-piece outfit).
  • Bring a sports bra or snug supporting bra to wear after the procedure.

If you are getting medication through a patch on your skin, remove it before entering the MRI suite. This is because any metal on the patch can heat up and cause burns during the MRI. Many patches have metal, some do not. Because we cannot know all products, we have made it our policy that any patch must be removed for your safety. Bring an extra patch with you to put on after the MRI. A fentanyl patch does not need to be removed. It is the only exception to our policy.

During Your Procedure

For the breast MRI, you will lie on your stomach. Your breast(s) will hang through a hole in the table. Your breast(s) are held in place with compression paddles. MRI images are taken to locate the area of concern.

Once the site is located, your breast will be cleaned. A local anesthetic will be injected to minimize discomfort during the biopsy. A very small incision will be made so that a needle can be inserted into the area. When the correct placement is confirmed, tissue will be withdrawn. It will be viewed under a microscope to look for abnormal cells. A small marker may be left at the spot so that the area can be identified if you need surgery. You will not be able to feel the marker and it will not set off metal detectors. After the biopsy, the area will again be cleaned and a pressure dressing will be put over it.

For many women, the most difficult part of the exam is lying with their arms over their head or at their sides for up to 45 minutes. While you are in the machine, you cannot move because movement blurs the images.

After Your Procedure

You will be able to return home after your procedure. You will be given instructions on how to care for the biopsy site.