Positron Emission Tomography (PET) Scan

This test is ordered primarily by epileptologists for children diagnosed with epilepsy who may require epilepsy surgery and need more information on where their seizures are coming from.

A PET scan is a test that combines computed tomography (CT) and nuclear scanning. A tracer (radioactive substance + glucose) is injected into the vein which travels to the brain and produces a signal on how the brain metabolizes the glucose (builds us and breaks down the glucose).

Areas in the brain that do not metabolize the glucose correctly light up differently and can help identify where the seizures are coming from in the brain.

For children 5 years and older, this test is done at St Joseph’s Health Care (SJHC) in London, Ontario in the Nuclear Medicine department located on the 5th floor, off Grosvenor Street. 

  • The PET program at SJHC will contact the families directly prior to the scan and provide any necessary instructions regarding preparation.  
    • No vigorous exercise for 2 days prior to the PET scan
    • The morning of the exam, please give your child their medications with water only.
    • The child is not allowed to eat, drink or chew gum for 5 hours before the scan because the test looks at how the brain metabolizes sugar. If your child has diabetes, please call your neurologist’s office for more information. 
  • An IV will be started on the child at SJHC when they arrive for their PET scan
  • At SJHC, a small amount of tracer will be injected into the vein through their IV, this liquid helps to show where the sugar is not being metabolized normally at in the brain.
  • The child will then need to be quiet and relaxed for about 30-45 minutes for the liquid to travel to the brain. There is a quiet room for the child and family to wait and relax in.
  • After the designated time has passed, the child will be taken into the room for the PET scan, they will have to be very still and quiet while the scan is being completed, this takes about 30 minutes.
  • When the scan is completed the child and family may go home.
  • The results of the scan will be provided at the next follow up with the neurologist. 

For children who need to be sedated, the epileptologist will send a PET request to SickKids who will call the family directly to set up the appointment.

PET scan

For more information about PET scans please visit:

PET (Positron Emission Tomography)/CT - St. Joseph's Health Care London
Positron emission tomography (PET) scan before epilepsy surgery - AboutKidsHealth