Positron emission tomography (PET) and computed tomography (CT) are two imaging tools that allow doctors to pinpoint the location of cancer in the body. PET-CT combines the two techniques to more accurately diagnose and locate disease.

The PET scan detects the metabolic signal of actively growing cancer cells in the body, while the CT scan provides a detailed picture of the internal anatomy that reveals the location, size and shape of cancerous growths. When the results of PET and CT scans are combined, the image provides complete information on cancer location and metabolism.

How to prepare

Clothing — Your child should wear comfortable clothing without any metal components, such as zippers and snaps.

Food and drink — Your child should not consume anything other than water for six hours before the scan.

Medications — Your child may take regular medications prior to arriving for the scan, if they can be tolerated on an empty stomach. Bring a list of your child's medications to your appointment.

The procedure

Your child will receive an injection of a radioactive tracer, which will take about an hour to disperse through the body. Your child will lie down on the scanner bed. The scan takes about 30 to 45 minutes. The entire procedure will take about two hours.

After the scan your child should drink plenty of fluids. A radiologist will interpret your child's PET-CT scan. Results are usually sent to your child's doctor within one to two days. Contact your doctor to discuss the results.