Cardiac MRI

Also known as: MRI of the heart, magnetic resonance imaging of the heart.

What is a Cardiac MRI?

Magnetic resonance imaging, or MRI of the heart, is a medical test that provides high-definition images of the heart (or body) and surrounding veins and arteries using a combination of magnetic and radio waves and a computer. Magnetic Resonance Angiography (MRA) is the portion of the test that looks at the blood vessels.

• Magnetic Resonance Angiography (MRA) is the portion of the test that looks at the blood vessels.
• Many times a Cardiac MRI or MRA will require contrast, a liquid substance to help create the details in the pictures.
• MRI does not use radiation but instead uses magnets. You and your child must be screened for any metal inside the body and will be asked to remove any jewelry or clothing that may contain metal. 
• ​A CMRA is not painful. The bed moves slowly through the tunnel and the camera remains around your child, never touching the child. A lot of children think the camera looks like a spaceship or doughnut!
• In order to get good results, it is very important that your child holds still for the scan. A Cardiac MRI and MRA may take between one to two hours.
• In some cases, your child may be given a mild sedative medication by mouth to help them stay calm and still.
• Patients who need stronger sedation medication (typically, children younger than 6 to 8 years-old and some older children with developmental delays) will be re-scheduled for a future scan under general anesthesia.

Is any special preparation needed for a Cardiac MRI?

• Metal jewelry will need to be removed prior to the test. Any personal belongings that contain metal can be locked in a secure cabinet during the scan. 
• Depending on the reason for the MRI, an intravenous catheter may be inserted into your child’s arm. Specific eating and drinking instructions may be given the day before the study.
• After being screened, one caregiver may accompany the child during the scan.
• All other visitors must wait in the waiting room and children must be supervised by someone of 18 years or older.

What are the risk factors of a Cardiac MRI?

There is no risk of radiation exposure. as no radiation is used during MRI. There are however a number of situations (for example in the presence of an implanted pacemaker, cochlear implants, other iron-based metal implants) where an MRI cannot be performed.

Women who are pregnant are not permitted to be in the MRI room during the scan. Please bring another adult who can stay with your child during the scan.

What to Expect During the Cardiac MRI Procedure

Step 1: Getting Ready

• From the Radiology Department waiting room, you will be brought to an exam room which we can call the “get ready room”.  Here your child will be seen by a nurse who will take your child’s vital signs and medical history.
• Please bring your child’s favorite toy or activity to provide distraction while in the “get ready room”.
• If contrast is required for the test, your child will also receive an “IV catheter” which is a tiny, plastic straw inserted into a vein in the hand or arm.
• Numbing medicine may be used to help your child feel as comfortable as possible during the IV placement.

Reviewed by: Dept. of Radiology and Dept. of Children's Experiences

This page was last updated on: September 16, 2025 12:45 PM