Jefferson University Hospitals

Frequently Asked Questions

How do I prepare for the exam?

24 hours prior to your exam:

  • Do not exercise
  • Drink at least 32 ounces (4 glasses) of water
  • Diabetics: follow instructions provided at time of scheduling

Day of exam:

  • Oncology: Fast for 6 hours prior to exam
  • Neurology: Fast for 4 hours prior to exam
  • Drink plenty of water (NO soda, coffee, juice or tea)
  • No gum or hard candy - sugar in the body can affect test results
  • Take any scheduled medications
  • Wear warm, comfortable clothing with no zippers

Please bring: 

  • Recent CT, MRI or PET CDs (if not done at Jefferson)
  • PET script/doctor's order
  • Insurance card(s)

How long does a PET/CT take?

You should arrive for your appointment 30 minutes prior to your exam. You can expect to be at the PET center for 2 to 4 hours. You will receive a small injection of radiolabeled sugar called FDG (fluorodeoxyglucose) in addition to oral contrast. You will then be asked to relax in the PET waiting area (30 minutes to 1.5 hours) before your scan begins. We need this time to allow the tracer to circulate properly. Some cells use this sugar more than others, and PET measures these differences.

What happens after the scan?

It is important that you drink plenty of liquids during the rest of the day and empty your bladder as often as possible.

Will my insurance cover PET?

Many insurance companies, including Medicare, are reimbursing for most PET procedures. Pre-approval may be required.

What if I need to reschedule my appointment?

We require 24 hours notice to reschedule or cancel your appointment. Without notice, you may be billed for the FDG injection, which is created specifically for you and is quite expensive.