Cardiac MRI

(Also called CMR)


Cardiac magnetic resonance imaging (cardiac MRI) is used to see the structure and function of your heart, valves and major arteries and veins. This test helps your doctors diagnose and assess coronary artery disease, heart failure and heart defects.


MRI uses radio-frequency waves and very strong magnets to produce images of the body. It does not use radiation. The MRI scanner (magnet) has a donut-shaped opening that a platform or table moves through. The scanner takes images of a patient as the patient passes through the machine while lying on the table.


  1. Upon check-in, you will be given a screening form asking you about anything that might create a health risk or interfere with imaging. An MRI technologist will review this form with you prior to starting the test.
  2. You will not be able to wear anything metallic or bring any metallic objects into the scanner room.  You will be asked to remove all metallic objects, such as jewellery or watches, and change into a hospital gown.
  3. You will be brought into the scanner room by the technologist and asked to lie down on the table.
  4. When the scanner operates, it may produce very loud noises. These loud noises are normal. You will be given earplugs for the noise and headphones to protect your hearing. 
  5. Some cardiac MRI scans require the use of a substance called a contrast agent to improve image quality. You will receive the contrast agent through an intravenous (IV) line in your arm. The technologist will set this up.
  6. The table will slowly slide into the scanner. You will be asked to lie very still during this time to ensure that the images are clear.
  7. You will be asked to hold your breath periodically throughout the examination. You will hear the breathing instructions from the headphones. The technologist will be able to speak to you, hear you, and observe you at all times.
  8. The images will be looked at by a radiologist (a doctor that specializes in reading medical images) or cardiologist. A report will be sent to the doctor(s) involved in your care.

Patient instructions

When booking your appointment

Please inform us if you are claustrophobic, or discuss this with your doctor.

Before your test

You will be asked to get blood work done prior to your test. This is done to ensure it is safe for you to receive the contrast injection. This contrast agent, gadolinium, is different from X-ray contrast. Gadolinium does not contain iodine and rarely causes allergic reactions or other problems.

On the day of your test

There is no specific preparation required for a cardiac MRI scan. You can eat and drink as usual prior to the test. Take your usual medications unless otherwise directed by your physician. Bring all of your medications with you in the original bottles.

After your test

There are no restrictions after the cardiac MRI scan.

Additional info

  • When you come to the Heart Institute, please check in with central registration in the front lobby. Then proceed to the S-Level and wait in the waiting room for your name to be called.
  • Doors open at 6 a.m. for all appointments. When doors are locked: please call 613-696-7000 ext. 13737.
  • The CMR takes about one-and-a-half to two hours to complete.
  • If you have any questions prior to your cardiac MRI scan, please call 613-696-7066, Monday to Friday, 7:30 a.m. to 4:00 p.m.

The image below is interactive

Touring instructions: Click and drag your mouse anywhere in the picture to move about the room. On mobile devices, drag your finger to pan the scene and pinch to zoom in or out. By clicking or tapping the lowercase "i" hotspots, you will learn about the equipment in the room and how it is used.