Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

MRI Guided Biopsy

Patient Information

Appointment Scheduling

Monday - Friday,
7:00 a.m. - 5:30 p.m.
7:10 a.m. - 3:30 p.m.

MRI Guided Biopsy

What is a core needle breast biopsy?

A MRI guided biopsy is a form of core needle biopsy. A core needle biopsy is a procedure used to determine whether a suspicious calcification or lump is cancer. Some lumps look much the same whether they are benign or cancerous, and the only way to find out is to remove a piece of the lump with a biopsy. The tissue removed is then sent to a pathologist who examines it under a microscope and determines whether or not it is cancerous.

Core needle biopsies are different from surgical biopsies, in that only small pieces of the lump are removed through a very small cut in the skin. Surgical biopsies usually remove the entire lump through a larger cut in the skin. Since most lumps are benign, doctors recommend core needle biopsies in most cases. Both types of biopsies, surgical and core needle, have the same accuracy rate. Core needle biopsies include stereotactic biopsies using x-ray, ultrasound biopsies and MRI guided biopsies.

Why do I need an MRI guided biopsy and what should I expect?

MRI is a very sensitive test to look for breast cancer. Sometimes cancer will show up in a breast MRI that is not seen in the mammogram or ultrasound. In these cases, the only way to take a biopsy (sample the tissue from the lump) is to guide a needle into the lesion using an MRI.

The procedure is performed while lying on the stomach. Once the radiologist identifies the finding, a computer program is used to determine the position of the needle in the breast. The breast radiologist administers local anesthesia, makes a small cut in the skin, and places the needle in the area of concern. The needle usually has a vacuum that will withdraw the tissue to sample the lump. The removed tissue is sent to the laboratory where a pathologist will examine it and determine the diagnosis. Usually the radiologist will leave a small metal clip is placed in the area of the biopsy. The clip helps identify the mass in future mammograms to prevent re-biopsy of the area. Also, if the lump is a small cancer, the clip helps the surgeon find and remove this very small area accurately.

What can I expect after the biopsy procedure?

You will be instructed to keep the breast area dry for 24 hours. Strenuous activity such as weight lifting or aerobic activity should be avoided during this time. Most women find that they can resume their normal activities the day after the procedure. It is important to carefully follow the post-procedure instructions so that any circumstances specific to you will be taken care of properly. In order to reduce the amount of bruising common in this procedure, the nurse will apply pressure to the biopsy site at the conclusion of the procedure. You will be instructed to place ice on your
breast at intervals during the remainder of the day. Though stereotactic biopsy is minimally invasive and is usually over quickly, there are some risks associated with it. As with any needle procedure, bleeding and infection at the biopsy site can occur, so be sure to follow all instructions carefully.

The pathology report is usually ready in a few days after the biopsy. This report will be sent to your referring physician and breast radiologist. Your physician or breast radiologist will call you with the results, ask how you are healing and answer any questions or concerns you might have.

Will the magnetic field interact with anything on or in my body?

The magnet used in breast MRI can interfere with metal objects in your body. Patients should make sure to alert the technologist before you have the procedure if you have a/an:

  • Artificial heart valve
  • Implanted drug infusion port
  • Infusion catheter
  • IUD
  • Artificial limb
  • Joint prosthesis
  • Implanted nerve stimulator
  • Metal pins, screws, plates or surgical staples

Breast MRI cannot be performed on people who have a/an:

  • Internal defibrillator
  • Cochlear implant
  • Clip for brain aneurysm
  • Implanted electronic device (pacemaker)

Patients are instructed prior to the procedure to remove:

  • Jewelry
  • Watches
  • Credit cards
  • Hearing aids
  • Hairpins
  • Metal zippers or clothing accessories
  • Removable dental work
  • Pens
  • Pocket knives
  • Eye glasses

How do I schedule a breast MRI or MRI guided biopsy?

If it is determined that you need a breast MRI or MRI guided biopsy, your referring physician will send orders to the Breast Center. Once these orders are received, a nurse will contact you to schedule your biopsy and conduct a pre-procedure phone consultation. The nurse will give you specific instructions about what to do before and after the procedure.

If you have questions or concerns about your procedure, please contact the Breast Center nurse at 281-274-8343, or to schedule an appointment call 281-242-PINK (7465).