When Your Child Needs a Magnetic Resonance Imaging (MRI) Scan
Magnetic resonance imaging (MRI) is a test that uses strong magnets and radio waves to form detailed images of the body. Your child lies in an MRI scanner while images are taken. The scanner is a long magnet with a tunnel in the center. An MRI scan is used to show problems with soft tissue (such as blood vessels), or with body parts that are hidden by bone (such as the brain). Most MRI tests take 30 to 60 minutes. Depending on the type of MRI your child is having, the test may take longer. Give yourself extra time to check your child in.
Before the test
- Your child may need to stop eating or drinking before the test. Each healthcare facility has its own guidelines on this. It also depends on the type of exam your child is having. Ask your child's healthcare provider if your child should stop eating or drinking before the test.
- Ask your child's provider if your child should stop taking any medicine before the test.
- Your child can follow his or her normal daily routine unless the provider tells you otherwise.
- Make sure your child removes any makeup. Makeup may contain some metal.
- Remove any metal objects like watches, jewelry, hearing aids, eyeglasses, belts, clothing with zippers, or other types of metal objects from your child. These things may interfere with the MRI scanner's magnetic field. Dental braces and fillings aren't a problem. But in many cases, MRI scans shouldn't be done on children who have metal implants.
- Remove ear (cochlear) implants before the MRI scan.
- Make a list of all known implanted devices and any metal in your child's body. These include shrapnel or bullet fragments. Discuss these with your child's healthcare provider and the MRI technologist. If there is any uncertainty, an X-ray may be taken of the involved body part to be sure.
- Follow all other instructions given by your child's provider.
MRI uses strong magnets. Metal is affected by magnets and can distort the image. The magnet used in MRI can cause metal objects in your child's body to move. If your child has a metal implant, he or she may not be able to have an MRI. People with these implants should not have an MRI:
- Ear (cochlear) implants
- Certain clips used for brain aneurysms
- Certain metal coils put in blood vessels
Be sure to tell the radiologist or technologist if your child:
- Has had previous surgery
- Has a pacemaker, surgical clips, metal plate or pins, an artificial joint, staples or screws, ear (cochlear) implants, or other implants
- Wears a medicated adhesive patch
- Has metal splinters in his or her body
- Has implanted nerve stimulators or drug-infusion ports
- Has tattoos or body piercings. Some tattoo inks contain metal and can become hot during the scan.
- Has braces. Your child can still have an MRI, but the radiologist needs to know about them as they can affect image quality.
- Has a bullet or other metal in his or her body
- Has any health problems
Also tell the radiologist or technologist if your child:
- Is pregnant, or you think your child might be
- Is allergic to X-ray dye (contrast medium), iodine, shellfish, or any medicines
- Gets nervous or scared in small, enclosed spaces (claustrophobic)
- Has any serious health problems. This includes kidney disease or a liver transplant. Your child may not be able to have the contrast material used for MRI.
- Is breastfeeding
During the test
An MRI scan is done by a radiology technologist. A radiologist is on call in case of problems. This is a doctor trained to use MRI or other imaging techniques to test or treat patients.
- You can stay with your child in the testing room until the scanning begins.
- Your child lies on a narrow table that slides into the MRI scanner.
- Your child needs to keep still during the scan. Movement affects the quality of the results and can even require a repeat scan. Your child may be restrained or given a sedative (medicine that makes your child relax or sleep). The sedative is taken by mouth or given through an intravenous (IV) line. A trained nurse often helps with this process. In rare cases, anesthesia (medicine that makes your child sleep) is also used. You'll be told more about this if needed.
- Contrast material, a special dye, may be used to improve image results. Your child is given contrast material by mouth or an IV line.
- A coil may be placed over the body part being tested. The coil sends and receives radio waves and also helps improve image results.
- The technologist is nearby and views your child through a window.
- If awake, your child can speak to and hear the technologist through a speaker inside the scanner.
- Your child is given earplugs to block out noise from the scanner.
After the test
- If a sedative is given, your child may be taken to a recovery room. It may take 1 to 2 hours for the medicine to wear off.
- Unless told not to, your child can return to his or her normal routine and diet right away.
- Any contrast material your child is given should pass through the body in about 24 hours. The provider may tell you that your child needs to drink more water or other fluids during this time.
- The MRI images are reviewed by a radiologist, who may discuss early results with you. A report is sent to your child's doctor, who follows up with complete results.
Helping your child get ready
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 that your child knows what will happen during the procedure. For instance, tell your child that you will be leaving the room and that he or she will be alone. But reassure your child that he or she will be able to communicate. Also describe what will happen-that your child will slide into the scanner, that it is a small space, and that the scanner noise will be very loud.
- 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. The MRI scanner causes no pain. If your child needs to be sedated, an IV may be inserted into the arm. This may sting briefly. If awake, your child may become uncomfortable from lying still.
- Allow your child to ask questions.
- Use play when helpful. This can involve role-playing with a child's favorite toy or object. It may help older children to see pictures of what happens during the test.
Possible risks and complications of MRI
- Problems with undetected metal implants
- Reaction (such as headaches, shivering, and vomiting) to sedative or anesthesia
- Allergic reaction (such as hives, itching, or wheezing) or very rarely, an illness called nephrogenic systemic fibrosis from the MRI IV contrast material