MRI of the Head: About Your Child's Test

What is it?

MRI (magnetic resonance imaging) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of the organs and structures inside the body. An MRI of the head can give your doctor information about your child's brain, eyes, ears, and nerves.

When your child has an MRI, he or she lies on a table, which moves into the MRI machine.

If you aren't pregnant, you may be able to stay in the room with your child during the test. You will also have to remove all metal objects while you are in the room.

Why is this test done?

An MRI of the head can help find problems such as infections, tumors, and bleeding. It can also show the type and size of head injuries.

How can you prepare for the test?

• Let your child know that an MRI doesn't hurt. But he or she may feel warm near the area being imaged.
• An MRI machine can be loud. Your child may get earplugs or headphones during the test. If you join your child in the room, you may need hearing protection as well.
• Ask the doctor if your child will need sedation to help relax before the test. You can also ask if your child will swallow a contrast material before the test.
• The doctor will tell you if your child should stop eating or drinking before the test.

How is the test done?

• Your child may have contrast dye put into their arm through a tube called an I.V.
• Your child will lie on a table that is part of the MRI scanner.
• The table will slide into the space that contains the magnet.
• Inside the scanner, your child will hear a fan and feel air moving. They may hear tapping, thumping, or snapping noises.
• Your child will be asked to hold still during the scan. And your child may be asked to hold their breath for short periods. You may need to help your child do these things.
• Your child will be kept safe and comfortable during the test. You may be able to stay in the room with your child. A technologist will watch through a window and talk with your child during the test.

What are the risks of your child's MRI of the head?

There are no known harmful effects from the strong magnetic field used for an MRI. But the magnet is very powerful. It may affect any metal implants or other medical devices your child has.

Risks from contrast material

• Contrast material that contains gadolinium may be used in this test. But for most people, the benefit of its use in this test outweighs the risk. Be sure to tell your doctor if your child has kidney problems or your teen is pregnant.
• There is a slight chance of an allergic reaction if contrast material is used during the test. But most reactions are mild and can be treated using medicine.
• If your teen breastfeeds and you are concerned about whether the contrast material used in this test is safe, talk to your doctor. Most experts believe that very little dye passes into breast milk and even less is passed on to the baby. But if you are concerned, your teen can stop breastfeeding for up to 24 hours after the test. During this time, use the breast milk that was stored before the test. Don't use the breast milk you pump in the 24 hours after the test. Throw it out.

How long does the test take?

The test usually takes 30 to 60 minutes but can take up to 2 hours.

What happens after the test?

• Your child will probably be able to go home right away. It depends on the reason for and the results of the test.
• Have your child drink plenty of fluids for 24 hours after the test if contrast dye was used, unless your doctor tells you not to. The fluids will help clear the contrast dye out of your child's body through urine.