Instructions for PET Scans

You will receive a call from a technologist at the Imaging Center to answer any questions you may have about your study and confirm preparation instructions outlined below. If you cannot keep your scheduled appointment, please call 501.906.3000 at least 24 hours in advance so that we may fill that time slot with another patient. Please read the full page of instructions in order to get the best results for your PET/CT scan.

What is PET imaging?

PET/CT imaging is a diagnostic procedure used in nuclear medicine to visualize metabolically active tissues using sugar (glucose) molecules labelled with the radiopharmaceutical FDG. The labeled glucose is incorporated into the actual cell and, once the cell has metabolized the glucose, the low-level radioactivity can be detected by the PET/CT scanner, which then generates images used for diagnosis and treatment. PET/CT scan results show the areas of abnormal glucose metabolization and exactly where the areas are located.

How long is the exam?

Please allow 2-3 hours for your PET/CT appointment. There are two stages of the PET/CT exam:

  1. You will receive an injection of the radiopharmaceutical FDG, after which you must wait 70-90 minutes, based upon your diagnosis, for your body to metabolize the FDG. You will be resting comfortably during this time. Next, you will be asked to empty your bladder right before the technologist begins your scan.
  2. You will be escorted to the PET/CT scanning area. You will be asked to lie down on a table that passes slowly through the PET/CT scanner. The scanner resembles a CT scanner. You should expect the scan to last approximately 30 minutes.

Instructions for PET/CT scan preparation:

For 24 hours prior to your scan, follow a low carbohydrate/low sugar diet. No strenuous exercise for 48 hours before the scan. If anything is eaten within 6 hours prior to the exam, there is a significant decrease in the absorption of the radiopharmaceutical FDG. This includes gum, candy, mints etc.

This will decrease the amount of radioactivity uptake in the abnormal cells, resulting in a sub-optimal scan.

All patients must follow the 24-hour diet.

*If you are diabetic and you take oral diabetic medications and your PET/CT scan appointment is in the morning – Do not eat or drink anything for 4 hours before your exam except water and non-diabetic medicines. DO NOT take oral diabetic medications.

*If you are a subcutaneous insulin dependent diabetic – Your appointment should be scheduled for late morning or afternoon. You may eat 1/2 breakfast and take 1/2 insulin. Then, do not eat or drink anything except for water 6 hours before your exam. Please bring your diabetic medication with you.