Positron Emission Tomography (PET)

What is positron emission tomography?

PET Scan Image Positron emission tomography (PET) is an imaging test that helps us find and determine the severity of cancers, neurological conditions, infections and cardiovascular disease.

For the test, we will give your child a radiopharmaceutical injection. Its emissions will be measured by the PET scanner.

The PET scan measures metabolism. Because cancer cells have a higher metabolism rate than other cells, the test can be particularly effective in finding cancer and determining whether it has spread, how it is responding to treatment and if a person is cancer-free after treatment.

PET is often used in conjunction with a CT scan to give a full three-dimensional view of an organ and the location of cancer within that organ. Our scanner combines both PET and CT images, giving us the important metabolic information from PET superimposed on the low-dose non-contrast CT.

What should you do prior to the exam?

There are many circumstances to consider before scheduling a PET scan for your child. Please refer to the information below or call 267-425-7090 if you have any questions prior to scheduling the scan.

Please contact the PET/CT Center before you schedule an exam if your child:

  • Has glucose levels less than 60 mg/dl or higher than 150 mg/dl
  • Just had chemotherapy
  • Just had surgery, if the surgical site is the primary site of investigation
  • Just had radiation therapy, if the radiated site is the primary site of investigation


We will consider sedation if you believe your child will be unable to stay calm and hold still during the procedure. Our nursing staff will call the evening before the scheduled appointment to review sedation requirements.

Diabetic patients

Your physician should make sure you have the proper medication and diet to ensure your child's glucose is at the desired level.

Your child will have a high protein, low-carb dinner the evening before the test and nothing to eat or drink after that. Your child will be scheduled for the first appointment in the morning.

General preparations

  • We will call you up to 48 hours before the appointment to review instructions.
  • If you need to cancel or reschedule your child's appointment, please notify the PET/CT Center 24 hours ahead of time.
  • Please make sure your child avoids strenuous or excessive exercise 48 hours prior to the appointment.
  • Your child may not eat for four hours before the appointment and may drink only water. Diabetic patients, see special instructions above.
  • If your child has a noted allergy to radiographic contrast, additional preparations may be necessary.
  • Dress your child in warm and comfortable clothes. The scanning room is kept very cool but we need your child to be warm for better image quality.
  • Avoid jewelry and metal (zippers, snaps, hair accessories) in the area that will be scanned.
  • If you have copies of your child’s previous imaging studies from another institution, please bring them for comparison. Please bring your child’s medication history as well.

Note: Parents will be allowed to accompany their child into the exam room, other arrangements should be made for siblings.

Women who are pregnant or may be pregnant will be asked to leave the exam room during the procedure. Please make sure that there is someone else available to accompany your child during the exam, if needed.

What should you expect during the exam?

  • You and your child will be brought to the Sedation Center for IV placement. The nursing staff will assess whether your child will need sedation and urinary catheterization at this time. Once we place the IV (your child will feel a small pinch), we will bring you to the PET/CT Center.
  • The technologist will give you and your child a thorough explanation of the test.
  • We will check your child’s blood sugar. If the levels are less than 60 mg/dl or above 150 mg/dl, we may have to delay or cancel the exam.
  • Your child will receive the radiopharmaceutical injection. We would like your child to relax and be still following the injection while the radiopharmaceutical is absorbed and distributed throughout the body. This may take up to one hour.
    If your child’s head and neck area will be evaluated, your child should avoid talking or chewing immediately before and after the injection.
    For evaluation of brain tumors, your child will be placed in a quiet and darkened room before and after the injection.
  • After the waiting period is over, your child will be asked to empty his bladder before going into the scanning room. The scan may take up to one hour, during which your child will need to lie still.

If you’d like, our child life specialists will help you prepare and support your child during the procedure. We can also arrange to have a child life specialist at your child's appointment to explain the procedure in developmentally appropriate ways and to help your child better cope with the stress of the hospital experience.

What should you do after the exam?

Please keep your child well hydrated. Make frequent bathroom trips for a few hours after the test.

If your child received sedation, follow any instructions given by the sedation nurses upon completion of this procedure. Sedated patients will be taken back to the Sedation Center for recovery.

Test results

The images from your child’s exam are interpreted on the same day and a report sent to your child's physician.

Your physician may call 215-590-2584 with questions about the exam.