MRI-Guided Breast Biopsy

WHAT IS AN MRI (Magnetic Resonance Imaging) BIOSPY?

An MRI breast biopsy is a procedure that uses computer technology to guide a needle to an abnormality seen on MRI.  The abnormality usually cannot be felt on breast self-examination or clinical examination by your primary care physician or seen by mammogram or ultrasound of the breast.

This is a simple and safe procedure performed at our center by our team of breast imaging specialists.  The procedure requires little recovery time and there is no significant scarring to the breast.


Although MRI breast biopsy is minimally invasive, there is a risk of bleeding whenever the skin is penetrated.  For this reason, if you are taking aspirin, you are advised to stop 7 days before the procedure.  Please inform our staff if you have any known bleeding problems or have been taking blood thinners.  If so, we will need to coordinate your biopsy with your referring physician.

Avoid the use of underarm powder or deodorant before the procedure.

Wear comfortable, two-piece clothing.

A breast biopsy always raises concern about cancer, and may make you anxious. We request that you have a relative or a friend present to lend support, and also to drive you home afterwards.




Yes, you may eat a light meal before the procedure. 



After placement of an intravenous catheter (a small sterile plastic tube) in a vein in your arm, you will be positioned face down on the MRI table.  Your breast to be biopsied will be placed through an opening in the breast coil on the MRI table and gently compressed to hold it still and to ensure accuracy during the procedure.  MRI images will be taken to confirm that the lesion is still present. Then using computer imaging, the radiologist will locate and identify the specific area of the breast tissue to be biopsied.

Your breast will then be cleaned with an antiseptic.  Next, the radiologist will numb the part of the breast to be biopsied by injecting local anesthetic with a tiny needle. You may feel some very brief stinging at this point.  After the local anesthetic has taken effect, the radiologist will place a pre-biopsy sterile plastic tube into the breast to the site to be biopsied. MRI images will be obtained to confirm placement.

Once placement is confirmed, a special type of needle will be inserted into the hollow plastic tube. Then, the tissue samples (cores) are acquired.  As the samples are taken, you may hear a humming from the biopsy instrument.  After the radiologist has retrieved all of the desired samples, a tiny metal clip may be placed in your breast at the biopsy site.  It is a very small, surgical-grade, titanium-based device designed to safely mark the biopsy site.  You cannot feel it once it is placed in your breast.  This clip will be used to localize the area if a further procedure is necessary.  If nothing else is needed, the clip just remains in place and should not cause any problems. 

When the procedure is completed, sterile gauze will be applied to the area for several minutes to prevent bleeding.  Polysporin ointment and a band-aid will be placed over the incision.  An ice pack will be applied to minimize swelling. You will be taken to the mammography department and a mammogram of the biopsied breast will be performed to document the marker clip placement. 

The radiologist, nurse or technologist will then discuss what to expect after the examination and what to do when you get home.  You will be provided written post biopsy breast care instructions prior to leaving the center.  Most patients are able to resume their usual activities the next day.


The entire MRI biopsy procedure should take approximately one hour for one area of concern. Only a few minutes of that time will involve needle placement and tissue sampling; the majority of the time is taken up by MRI scanning.


The tissue specimens will be sent to UNC Pathology for review. A diagnosis will be available within 3 to 4 working days.  If you have been seen by the UNC Surgical Breast Clinic, you should obtain your results from them. Otherwise, you need to contact the radiologist who performed your biopsy to obtain your results.