Cardiac MRI

A cardiac MRI (magnetic resonance imaging) is a type of heart scan. It uses a strong magnetic field, radio waves and a powerful computer to capture images of your heart and blood vessels from outside your body.

Your doctor may order this test to get more detailed information about the structure of the heart and how well it works. This can help make a new diagnosis or provide more information about a current heart condition.

Before your appointment

Before the day of your appointment, let the doctor know if you have:

• an implantable device (e.g. pacemaker or ICD)
• cochlear implants (inner ear implants)
• an infusion pump
• a neurostimulator
• an artificial heart valve
• metal clips in your brain
• metal fragments in your eyes
• any metal products in your body (e.g. joint replacement)
• kidney problems
• an allergy to contrast dye
• or if you are pregnant.

The doctor will let you know if the test is suitable for you.

If you’re claustrophobic, or don’t like small spaces, tell the team before the day. They might be able to give you something to help you relax (sedation). If you have sedation, you will need someone to drive you home.

What happens?

The MRI will be done at a hospital or in a clinic.

You’ll be asked to change into a gown and remove all metal objects such as jewellery and watches.

Sticky pads (electrodes) will be placed on your chest to monitor your heart during the scan. If a contrast dye is being used, you will have an IV (intravenous) line put in your arm. A small amount of contrast dye (x-ray dye) is injected into a vein through the IV. The dye is not harmful.

You will be asked to lie on your back on the table. The table moves into the MRI scanner, which is a bit like a tunnel.

The scanner is noisy, so you’ll be given headphones to wear. The person doing the scan can talk to you through these and you may be able to listen to music. You’ll be given a call bell to press if you need assistance.

You’ll need to keep still and relaxed in the scanner and hold your breath for short periods. This is to make sure the images are clear. The scan lasts 35 to 40 minutes.

After the test

If contrast dye has been used, drink plenty of water to flush it from your system. If you’ve had sedation, you will need someone to drive you home.

You won’t get the results on the day. They will be sent to the doctor who ordered the test.

Key things to remember