Breast MRI

Breast MRI Montreal

What is Breast MRI?

Breast MRI is a new imaging technique that is being used for certain women at very high risk for cancer, whose breast tissue can’t be fully evaluated in the usual ways. In some of these women, physical exam, mammogram, and ultrasound alone may not give enough useful information.

Indications for a Breast MRI

  • To help mammography and high resolution ultrasound in monitoring high risk patients or patients with breast implants
  • To better evaluate the local extent and staging of established breast cancer prior to surgery, or to help assess residual tumor after surgery
  • To help monitor the efficiency of neo-adjuvant (prior to surgery) chemotherapy, immunotherapy or hormonal therapy
  • To better assess a local recurrence or to seek out an occult breast primary when associated with involved axillary lymph nodes.

How is Breast MRI different from Mammography?

  • MRI, or magnetic resonance imaging, is done using a strong magnetic field and radio waves.
  • Mammograms are done by x-ray.
  • MRI requires intravenous (IV) injection of a contrast fluid.
  • MRI shows very subtle changes in breast tissue, which could mean early breast cancer.
  • However, these changes often look the same as normal breast tissue.
  • MRI does not show calcium deposits, a common sign of early cancer which is seen very well on mammogram.
  • The overall accuracy for finding breast cancer is lower with MRI.
  • Mammogram is still the best screening test for breast cancer.

What happens in a Breast MRI?

Breast MRI may require traveling to another site that has specialized equipment and trained personnel.

Ideally, a scan should be done on day 7-12 of the menstrual cycle, when hormonal breast changes are the least. It is possible that women will be asked to discontinue hormone replacement therapy for 6 weeks. This will be discussed at the time of scheduling.

When you arrive, an intravenous line (IV) will be started in your arm. The machine is very noisy, and you will get earplugs to protect your hearing. You need to lie on your stomach, and hold very still as the scan table slides into the scanner. The scan takes about 45 minutes.

Hundreds of images are obtained during the scan. These are studied by a Radiologist, with the help of a computer.

The report is sent to the doctor who ordered the study. If anything unusual is seen, you will be called back for more testing, or a biopsy. Many biopsies can be done with a needle.

For more information or to book an exam, we encourage you to contact us.