Your Child's Heart MRI or CT Scan

Your Child's Heart MRI or CT Scan

Radiographic studies such as cardiac magnetic resonance imaging (MRI) and cardiac computed tomography (CT) are called imaging tests. They allow the doctor to check for problems in the heart. The tests are painless and noninvasive. Your child’s doctor will discuss with you why your child needs one or both of these tests.

What Are Cardiac MRI and CT?

Boy lying on back on scanner table with IV in arm. Healthcare provider is preparing table to go into ring-shaped opening.
A cardiac MRI scan takes pictures of your child’s heart.

Both cardiac MRI and cardiac CT are used to take images of the heart.

  • Cardiac MRI uses strong magnets and radio waves. A cardiac MRI scan can show problems with heart structure, abnormal blood flow, or tissue damage.

  • Cardiac CT uses x-rays and computer processing technology. A cardiac CT scan can show problems with heart structure, especially if there is damage to blood vessels.

Before the Scan

You may need to do the following before your child’s cardiac MRI or CT scan:

  • Don’t give your child anything to eat or drink for 4–6 hours before the scan.

  • Remove any metal objects (such as glasses, jewelry, belts, or clothing with zippers) from your child’s body.

  • Tell your child’s doctor and the healthcare professional performing the scan if your child wears a medicated adhesive patch.

  • Follow all other instructions given by the doctor.

Let the technologist or doctor know if your child:

  • Has metal implants (such as pacemakers).

  • Has allergies.

  • Has had surgery.

  • Has any other significant health problems.

  • Gets nervous or scared in enclosed spaces.

During the Scan

The scan is performed by a technologist or radiologist. A radiologist is a doctor trained to diagnose and treat problems with imaging technology. The scan can also be performed by a cardiologist with special training in radiology. A cardiologist is a doctor trained to diagnose and treat heart problems. The scan takes place in a hospital. A cardiac MRI scan lasts about 60–90 minutes. A cardiac CT scan lasts about 30 minutes.

  • You can stay with your child in the testing room until the scanning begins.

  • Your child lies on a table that slides into the scanner.

  • Your child must stay still during the scan. Movement affects the quality of the results and can even require a repeat scan. To help keep your child still, restraints may be used. Your child may also be given a sedative (medication that makes your child relax or sleep). This is done by mouth or an intravenous (IV) line. Or, your child is given anesthesia (medication that makes your child sleep and not feel pain). This is done by facemask or IV. A trained nurse or doctor (anesthesiologist) is in charge of this process.

  • Contrast dye may be used to improve image results. Your child is given contrast dye by mouth or an IV line.

  • A coil may be placed over the heart during a cardiac MRI scan. The coil sends and receives radio waves and helps improve image results.

  • The technologist is nearby and views your child through a window at all times.

  • If awake, your child can speak to and hear the technologist through a speaker inside the scanner.

  • During a cardiac MRI scan, your child will get earplugs to block out the noise from the scanner.

  • During a cardiac CT scan, older children may be asked to hold their breath at certain points to improve image results.

After the Scan

  • If a sedative or anesthesia was given, your child may be taken to a recovery room. It may take 1–2 hours for any medications to wear off.

  • Unless told not to, your child can return to his or her normal routine and diet right away.

  • Any contrast dye your child is given should pass through the body in about 24 hours.

  • The images are reviewed by a radiologist and cardiologist. The cardiologist will follow up with you with complete results.

Risks and Possible Complications of Cardiac MRI and CT Include:

  • Radiation exposure from x-rays (only with CT)

  • Problems with undetected metal implants (only with MRI)

  • Reaction (such as headaches, shivering, and vomiting) to sedative or anesthesia

  • Allergic reaction (such as hives, itching, or wheezing) to contrast dye

How to Help Your Child Prepare

You can help your child by preparing him or her in advance. How you do this depends on your child’s needs.

  • Explain the test to your child in brief and simple terms. Younger children have shorter attention spans, so do this shortly before the test. Older children can be given more time to understand the test in advance.

  • Make sure your child understands which body part(s) will be involved in the test.

  • As best you can, describe how the test will feel. An IV may be inserted into the arm or hand to give medications or contrast dye. This may cause a brief sting. Your child won’t feel any discomfort once the medications take effect. If awake, your child may become uncomfortable from lying still.

  • Allow your child to ask questions and answer these questions truthfully. Your child may feel nervous or afraid. He or she may even cry. Let your child know that you’ll be nearby during the test.

  • Many hospitals have a child life specialist. This person is specially trained to help children understand what to expect during their time in the hospital. Books, videos, dolls, and toys may be used to help explain the procedure to your child. Be sure to ask your child’s doctor about the resources available at your hospital.