Magnetoencephalography (MEG)

What is MEG?

MEG is an imaging technique that maps brain activity by recording magnetic fields made by the electrical currents in the brain. It uses very sensitive magnetometers and produces a magnetic source image.

MEG is:

  • Noninvasive and pain-free
  • Safe, with no known side effects or radiation exposure
  • Accurate and detailed

MEG can be a valuable tool to locate seizure sources before surgery or perform motor or sensor mapping.
In addition, researchers use MEG to study the brain and brain activity, which may help lead to discoveries that will help patients with autism, epilepsy and other brain disorders.

How do I prepare my child for a MEG?

There may be special rules about preparing for your child’s MEG, including for eating, sleeping and medications. Be sure to write down and follow any directions you are given before the appointment. If you forget or have questions, call us at 832-TC4-XRAY (832-824-9729). 

If your child is being evaluated for epilepsy, he must not sleep the night before the test.

Read more about how to prepare for your child’s visit.

What happens during a MEG?

Preparing for the test

Before and during the test, a child-life specialist can help your child relax and feel more comfortable by providing coaching and distraction tailored to your child’s developmental level. Sometimes this helps reduce the need for sedation.

If your child is young or unable to lie still, he may need to be given medicine to help him relax or sleep. This is also called sedation or anesthesia. Depending on the test, sedation or anesthesia may be given by mouth, shot or IV (a needle connected to a tiny tube).

Read more about sedation.

The doctor may want your child to be given contrast medicine during the test. Contrast is a special medicine that helps certain body parts show up better on the image. It may be given as a drink or with an IV. If contrast is given in an IV, your child may notice a warm feeling and a metallic taste. These last only for a few moments. If your child drinks the contrast, it may have a slightly unpleasant taste that fades soon.

If your child needs an IV, a needle will be inserted into your child’s skin to give the medicine. Your child might feel a pinch or a poke when the needle goes into the vein. We have ways to help with the pain if your child needs it.

Your child may be given a brief MRI before the MEG.

Because the MEG uses a strong magnet, you and your child must not take certain items, such as implanted medical devices and braces, into the exam room.

Be sure to tell the technologist if your child has:

  • Allergies to the contrast medicine
  • Any implanted devices or braces

The test

The technologist will position your child on the MEG table, probably on his back. Three leads will be placed on your child’s head. Then your child will be moved into the MEG scanner helmet. He will need to hold very still or the scan may have to be repeated.

The MEG scanner is quiet, and your child will not have any pain or discomfort. Holding still during the exam can make some children uncomfortable.

Depending on the type of test your child is having, the bed may move into a seated position, and your child may look at a video monitor and press buttons.

If your child receives sedation or anesthesia, you can return to the exam room when the test is over. We will monitor your child closely until he is fully awake. When you leave, follow any instructions about activity and dietary restrictions.

How do I find out results of the test?

The technologist cannot tell you the results of the test. A pediatric radiologist will analyze the images and provide a report of the findings to your child’s doctor. Your child’s doctor will then notify you of the results.

Why choose Texas Children’s?

As one of the leading and largest pediatric hospitals in the United States, Texas Children’s has the expertise and experience to perform the most modern and accurate imaging tests, including magnetoencephalography (MEG).

  • Board-certified pediatric neuroradiologists and specially trained support staff
  • Cutting-edge technology and equipment designed especially for children
  • Procedures personalized to your child
  • Child-friendly environment that helps you and your child feel at ease
  • Child-life specialists who help your child relax with age-appropriate game and activities
  • Customized, safe methods to sedate your child if necessary

MEG is available at Texas Children’s Hospital -- Texas Medical Center. Women’s Pavilion Level 5

If you have questions or want to make an appointment, call 832-TC4-XRAY (832-824-9729). An order from your doctor is needed to make an appointment.