Cardiac-Related Diagnostic Methods

What is a cardiac MRI?

MRI stands for Magnetic Resonance Imaging. An MRI uses a powerful magnet, radio waves and a computer to acquire pictures of just about any body part, including the heart. Cardiac MRIs, just like all MRI's expose the patient to absolutely no radiation.

Cardiac MRIs are performed on MRI machines equipped with special software and additional equipment. At Cincinnati Children's Hospital Medical Center, two of our MRI machines are so equipped, both located at our main campus.

A parent or legal guardian needs to be present to sign a consent form to treat the patient. This is signed at the front registration desk.

Why would a cardiac MRI be done?

Cardiac MRIs are usually for evaluation of the heart of patients with very specific conditions. At Cincinnati Children's, they are most commonly performed on teenagers and young adults with previously operated congenital heart disease.

A cardiac MRI takes very clear pictures of the heart and blood vessels in the chest, regardless of the patient's size (large size can often limit the quality of other types of imaging, such as ultrasound/echocardiography). In addition, cardiac MRI is able to provide detailed measures of certain heart parameters unavailable by other means.

Who performs Cardiac MRI?

The Cardiac MRI test is performed by a specially trained MRI technologist, with continuous assistance from a pediatric MRI Radiologist, an MRI Physicist, and a pediatric MRI Cardiologist. The input of all these personnel is essential for useful studies, and explains why the test is available only at Cincinnati Children's Main Campus.

Who Interprets the Cardiac MRI?

The study will be interpreted in detail by both a pediatric MRI Cardiologist and pediatric MRI radiologist. Preliminary MRI results will be available to you and your child's pediatric cardiologist immediately after the scan from the MRI cardiologist. The final report including detailed numerical analysis and movie clips will be available to your child's pediatric cardiologist within a few days.

Is Sedation Required?

Most patients do not require sedation. Some young adult patients do have claustrophobia from lying in the magnet for a prolonged period. For these patients, a single dose of oral diazepam (Valium) usually provides adequate anxiety relief for them to tolerate the scan.

Patients also must be able to follow instructions carefully, particularly in holding their breath for several seconds on command. For this reason, cardiac MRIs done in children less than 8 years of age often require general anesthesia sedation.

When general anesthesia is required, the Division of Anesthesiology runs the sedation, under the guidance of an Attending Anesthesiologist.

My child has had metal clips/ implants placed. Can he/she still undergo a cardiac MRI?

Usually. The only implanted devices absolutely not allowed in the MRI scanner are pacemakers and defibrillators, since the powerful MRI magnet can theoretically disrupt function of these devices. The magnet does not disrupt function of other metal devices, such as implanted articial heart valves.

Any removable metal should be removed as well. However, if your child has had numerous metal devices placed, in his/her chest, artifact from the devices may obscure useful pictures of the heart. Although this does not make the procedure unsafe, it may make it un-useful. Therefore, in patients will several metal devices and/or coils in the chest, a chest x-ray may be performed prior to the MRI so that the MRI radiologist and cardiologist can make sure there will not be too much artifact.

Before the Scan

Before coming to the hospital or MRI facility, talk to your child about the scan. Depending on your child's reason for the exam, he/she may require an IV for the MRI. Prepare your child as you see fit. The day of the exam, technologists will further explain the scan to your child and answer any questions he / she may have.

You should receive a phone call to confirm your appointment 24 to 48 hours prior to the MRI exam. We prepare all patients with specific eating and drinking instructions in case an IV will need to be given during the test. You will also be instructed to arrive 30 minutes prior to your scheduled scan to allow time for registration, removal of all jewelry and metal and IV placement if need be.

The MRI machine is a large magnet. Therefore, dress your child in comfortable clothing with no metal snaps or zippers. Remove all metal hair barrettes or rubber bands and earrings. Check any toys or stuffed animals for metal parts before bringing them to the MRI area.

Children are encouraged to bring a favorite music CD or video to watch during the MRI scan. In rare instances, the music and/or video may interfere with the scan of the body part being examined.

During the Scan

The MRI machine is a large magnet that is in the shape of a tunnel. Whatever body part that is being scanned needs to be in the center of the tunnel.

While your child is lying on a table in the middle of the tunnel, nothing will touch or hurt him / her as the pictures are being taken. The technologist will explain to your child that when we start to take the pictures he / she will hear loud knocking or banging noises. Whenever your child hears the loud noise, he / she will need to hold perfectly still. To protect the child's hearing, he / she will be given earplugs or special headphones to hear a CD or video.

The MRI can be as short as 20 minutes, but sometimes can last for up to 2 hours. During that time, your child has to hold perfectly still (like a statue). Several series of pictures will be taken. Pictures could last between 30 seconds to 7 minutes each. The technologist will talk to your child between each set of pictures to assure that he / she is okay.

Parents are welcome to accompany their children into the scan room, as long as you are not pregnant and if you remove all jewelry and metal. Parents will be given earplugs during the scan.

Sometimes an IV is also used to give a small amount of contrast material during the test. This is a clear fluid that shows up on the pictures. The IV will remain in place until the scan is completed. If your child experiences any discomfort, please tell the technologist.

If your child is unable to hold still for his / her pictures and he / she was scheduled for an MRI without sedation, you will most likely need to reschedule your appointment with sedation and return at a different date.

After the Scan

When the MRI pictures are complete, your child will lie on the table a few moments longer while a radiologist checks to make sure there are enough pictures. Sometimes a set of pictures will need to be repeated (this takes 5-10 minutes).
Once the doctor checks the pictures and confirms that the scan is complete, the IV will be removed and you may leave.

The contrast material will exit your child's body through his / her urine within 24 to 48 hours after the procedure. The color of the urine should remain normal.

Revised 9/06