Magnetic Resonance Imaging (MRI)

What is MRI?

For children with epilepsy, Magnetic Resonance Imaging (MRI) may be ordered to detect any damage or scar tissue in the brain that may be causing seizures. MRI scans are large, tunnel-like machines that use a large magnet, radio waves and a computer to make clear, detailed pictures of the inside of the body. MRI is painless, does not use radiation and has few known side effects. During the test, your child will lie flat on an examination table that slides into the MRI machine.

MRI uses magnetic fields and radio waves to make detailed maps of the brain. The resulting data is analyzed by a team of specialists to determine areas of the brain that are abnormal, including soft tissue and vascular structures.

Functional MRI (fMRI)

fMRI uses the same scanner as an MRI but studies different aspects of the brain. Instead of studying the structure of the brain, fMRI studies function of the brain. When a section of the brain is in use, blood flow will increase to that portion of the brain. (i.e., If a person is speaking, the part of the brain that controls language will be in use. If a person is waving, the part of the brain that controls movement will be in use.) The blood flow and oxygenation levels of the blood are recorded during a fMRI to identify areas of the brain that are not functioning optimally.

During a standard MRI test, a patient will remain completely still, while during a fMRI your child may be requested to perform a variety of tasks. Tasks such as speaking or moving will help doctors identify areas of the brain that may be causing seizure activity.

Resting-State fMRI (R-fMRI)

R-fMRI uses the same technique as a fMRI, studying blood flow in the brain, but analyzes the data when a patient is at rest, rather than performing particular tasks or function. Research has shown that when a child is at rest, certain networks are universally connected in healthy brain tissue. The purpose of this test is to study the brain in a resting state and identify any anomalies in the connectivity.

Intraoperative MRI

An intraoperative MRI is an MRI scan that is incorporated into an operating room. Intraoperative MRI is used while a patient is actively undergoing brain surgery. During surgery, neurosurgeons use the intraoperative MRI as a type of high-tech “GPS” into the brain to ensure that unhealthy tissue is completely resected and to protect healthy tissue, leaving it unharmed and in-tact.

Texas Children’s Hospital is one of the few pediatric centers in the country using intraoperative MRI during neurosurgery. To learn more about how the procedure works, please visit the Texas Children’s Epilepsy Center’s Minimally Invasive Epilepsy Surgery page.


Magnetic Resonance Spectroscopy (MRS)

MRS takes place in an MRI scan and studies the metabolic activity in the brain, specifically protons and hydrogen ions. By understanding the metabolic functions in the brain, doctors can distinguish between healthy brain tissue and abnormal brain tissue. The ability to differentiate between the tissue helps identify the source of seizure activity. If a tumor is present, an MRS scan can determine the aggressiveness of the tumor or if the tumor’s cell growth is decreasing as a result of radiation or other treatments.

Texas Children’s Department of Radiology

MRI tests are given at the Texas Children’s Department of Radiology, one of the nation’s largest and most experienced pediatric imaging departments. Our radiology department is home to the latest, most advanced technology. In addition, the radiological technicians at Texas Children’s have specialized expertise in personalized, child-friendly care.

Because Texas Children’s radiology department focus only on babies, children, and teens, we offer specialized equipment and techniques that ensure accurate and safe MRIs, including:

  • 3T and 1.5T machines
  • Wide-bore 1.5T machine for larger patients
  • fMRI (functional MRI)
  • Board-certified pediatric radiologists and pediatric neuroradiologists
  • Specially trained technicians and support staff
  • A variety of tools to help your child relax during the procedure, including child-life specialists, movies and music and a soothing, child-friendly environment

Girls 6 years and above and boys 8 years and above (who are developmentally typical) will be scheduled without sedation. Texas Children’s offers motion correction for some testing sequences for children who have difficulty remaining still, which may help reduce the need for sedation.

Learn more about preparing your child for a MRI.

Before an MRI

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.

Since any movement can make the picture blurry, you child must lie completely still inside the scanner, usually for 15 to 90 minutes. If your child is young or unable to lie still, he may need to be given medicine with an IV to help him relax or sleep. If your child requires sedation, the complete process may last up to 4 hours.

Your child will 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 presented as a drink or with an IV. If contrast is delivered through 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.

During an MRI

Your child will be positioned on the moveable MRI table according to the type of scan. Straps or pillows may be used to help your child stay in the correct position. Then the table will move into the scanner’s tunnel. It may feel close, but it will not touch your child.

The scanner makes loud thumping noises while it takes pictures. It may sound like a shoe in the dryer or a loud beeping noise. Your child will be given earplugs and headphones. In addition, we offer video goggles designed specifically to help MRI patients with noise, claustrophobia, and anxiety. Your child can pick a movie to watch or music to listen to during the MRI procedure.

You can go into the MRI room with your child. If your child is sedated, you will be asked to return to the waiting room when your child falls asleep.

After an MRI

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. Once the MRI test concludes, your child may resume regular activity and diet and should not experience any side effects.

Many children receive MRIs, and it can often be a scary experience if they are unprepared or don’t know what to expect.