Shared Medical Services What is PET/CT?

What is a PET/CT? | What to expect

When you arrive, we will take a review of your history and any past exams.

For the PET portion of the exam, you will receive an injection of radioactive material similar to that which 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 and completely eliminated by 24 hours after injection.

For most studies, you will have to wait for the radiopharmaceutical to distribute itself — typically 30 minutes to an hour. 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 procedure can vary depending on what we are looking for and what we discover along the way. Plan to spend two hours with us.

After the exam you may return to 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 radiopharmaceutical that may still be in your system.

In the meantime, we’ll begin preparing the results for review by a interpreting physician and then by your physician, who will tell you what we’ve learned.


Wondering what your doctor will be reviewing? Click below on a thumbnail to view an actual PET / CT scan.