How to prepare for the test

Last Modified: April 18, 2002

This information was provided by an unrestricted educational grant from Integral PET Associates, LLC.

How to prepare for your PET scan

  • Patients should bring a list of the medications they are taking.
  • Patients should also bring all previous studies, including CT and/or MR films and reports, as well as their chemotherapy history, including date of most recent treatment, with them.
  • Patients must fast overnight prior to a PET scan. Afternoon patients may eat a light meal six hours prior to exam.
  • Patients must NOT exercise for 3 days prior to exam.
  • Patients should drink water before beginning fast and drink lots of water after beginning fast. Continue to hydrate.
  • Oncology patients must fast overnight, or at least 6 hours prior to PET scan.
  • Cardiology patients may eat a light breakfast. It must be low fat.
  • Diabetic patients may eat normal, low fat meals, and take usual insulin dose.

The Test

After you register, you will be escorted to the PET prep room. The radioisotope or FDG is injected into the patient. When it is time for the PET scan to begin, you will lie on a table that slides into the scanner, a donut-shaped machine that resembles a CT scanner. The table will slide through the PET scanner. For most patients, the PET scan takes about two hours to complete, depending on whether the whole body, or a particular part of the body is scanned.