What is A PET/CT Scan?
PET/CT combines the functional information from a Positron Emission Tomography (PET) exam with anatomical information from a Computed Tomography (CT) exam in one single exam.
A PET scan detects changes in cellular function specifically, how your cells are utilizing nutrients like sugar and oxygen. Since these functional changes take place before physical changes occur, PET can provide information that enables your physician to make an early diagnosis.
The advantage of CT is its ability to take cross-sectional images of your body. These are combined with the information from the PET scan to provide more anatomic details of the metabolic changes in your body.
The PET exam pinpoints metabolic activity in cells and the CT exam provides an anatomical reference. When these two scans are fused together, your physician can view metabolic changes in the proper anatomical context of your body.
Please follow the instructions below prior to your PET/CT. If you have any questions, please contact Quincy Medical Group at 217-277-4070.
- Do not eat or drink anything except water for 4 hours prior to the exam if you are a diabetic patient and 6 hours prior to your exam if you are a non-diabetic patient.
- Meal prior to your exam should be high protein and low carbohydrate. Please AVOID bread, pasta, cereals, grains, fruit, candy, and other high carbohydrates/sugar foods.
- We encourage you to drink approximately 32 ounces of water about 1 to 2 hours prior to your exam.
- When taking your morning medication, only drink water. You may eat a few soda crackers if you’ve been advised not to take your medications on an empty stomach.
- If you are diabetic, let us know ahead of time so we can work with your physician to determine the safest possible way for you to prepare for your exam.
- No nicotine use or chewing gum the day of the exam.
- Avoid strenuous physical activity for 24 hours prior to the exam. (Heavy lifting, vigorous exercise, etc.)
- If applicable, bring outside films and reports – CT, MRI, and PET/CT.
- Do not wear anything metallic. (i.e. underwire bras, belts, zippers, buttons.)
- In addition, please let us know if you might be pregnant or are currently breastfeeding.
Frequently Asked Questions
Your PET/CT exam results may have a major impact on your diagnosis, and course of treatment selected by your physician.
A PET/CT study not only helps your physician diagnose a problem, but it also helps your physician predict the likely outcome of various therapeutic alternatives, pinpoint the best approach to treatment, and monitor your progress. If you are not responding as well as expected, you may be switched to alternative therapy.
Ask your physician what he or she hopes to learn from your PET/CT exam.
When you arrive, we will review your history and any past exams.
For the PET portion of the exam, you will receive an injection of radioactive material similar to what is used for bone scans and other nuclear medicine exams. This is a radioactive tracer that must pass multiple quality control measures before it is used for any patient injection. PET radiopharmaceuticals lose their radioactivity very quickly (two hours) and only very small amounts are injected. In all cases, the majority of radioactivity will be eliminated from the body approximately 6 hours after injection.
After Your injection, you will be asked to wait in our injection suite for one hour while the radiopharmaceutical distributes. During this time you will be asked to relax.
During the exam, you will lie very still on a comfortable table that will move slowly through the scanner as it acquires the information needed to generate diagnostic images.
The PET/CT scan should last between 20 and 45 minutes. The exam can vary depending on what we are looking for and what we discover along the way. Plan to spend two to three hours with us.
You may return to the designated area as soon as the exam is complete. Unless you’ve received special instructions, you will be able to eat and drink immediately. Drinking lots of fluids soon after the exam will help remove any of the radiopharmaceuticals that may still be in your system.
In the meantime, we’ll begin preparing the results for review by our interpreting physician, and then by your physician, who will tell you what we’ve learned.
Be assured that PET/CT exams are a safe and effective diagnostic procedure. The radiopharmaceuticals used in PET do not remain in your system long, so there’s no reason to avoid interacting with other people once you’ve left. To be extra safe, wait for a few hours before getting too close to an infant or anyone who is pregnant.