Heart Center: Diagnostic Imaging
Magnetic Resonance Imaging (MRI) is a non-invasive technique used to detect heart defects. MRI uses a powerful magnet, radio waves and a computer to take very clear pictures of the heart and blood vessels in the chest.
Some patients experience claustrophobia from lying in the magnet for a prolonged period, so a sedative is provided to calm them. Cardiac MRIs performed on young children often require general anesthesia.
Before the Scan
Before bringing your child to Children’s for an MRI, it is important to talk to them about the scan and to discuss what they can expect. Depending on your child's condition, he or she may require sedation. If they are older, it is important to stress the importance of following the MRI operator’s instructions. The day of the exam, technologists will further explain the scan to your child and will be happy to answer any questions.
Since the MRI machine is a large magnet, be sure your child is wearing comfortable clothes with no metal snaps or zippers. Remove all metal hair barrettes and earrings, and 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, though, 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 in the shape of a tunnel. While your child is lying on a table in the middle of the tunnel, nothing will touch or hurt him or her as the pictures are being taken. The technologist will explain that when we start to take the pictures, your child will hear loud knocking or banging noises. Your child must remain still during these noises.
The process can be as short as 20 minutes, but sometimes it can last up to 2 hours. Several series of pictures will be taken, and each one could last between 30 seconds to 7 minutes. During these times, your child must remain perfectly still. The technologist will talk to your child between each set of pictures to ensure that he or she is okay.
As long as they are not pregnant, parents are encouraged to accompany their child into the scan room. We only ask that you remove all jewelry and metal. Parents will be given earplugs during the scan.
Sometimes an IV of clear fluid also is used during the test to allow a small amount of contrast material to appear on the pictures. The IV will remain in place until the scan is completed, and if your child experiences any discomfort, they should tell the technologist.
If your child is unable to hold still for his or her pictures and was scheduled for an MRI without sedation, you will most likely need to reschedule your appointment with sedation and return at a different date. It is of paramount importance that your child remains still throughout the entire process to ensure accurate pictures are taken.
After the Scan
Once 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, and this usually takes only five to 10 minutes. After the doctor checks the pictures and confirms the scan is complete, the IV will be removed, if your child required one, and you may leave.
The contrast material supplied by the IV will exit your child's body through his or her urine within 24 to 48 hours after the procedure. The color of the urine should remain normal.