Our goal is to provide the best possible care for you and your family. Please take a few minutes to read this general information on PET/CT to help you understand and prepare for your exam. Your physician will also be able to answer additional questions you may have about your exam.
What is PET/CT?
PET/CT combines the functional information from a positron emission tomography (PET) exam with the anatomical information from a computed tomography (CT) exam into one single exam.
A PET scan detects changes in cellular function – how your cells are utilizing nutrients such as 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.
A CT scan uses a combination of X-rays and computers to give the radiologist a non-invasive way to see inside your body. One advantage of CT is its ability to rapidly acquire two-dimensional pictures of your anatomy. Using a computer, these 2-D images can be presented in 3-D for in-depth clinical evaluation.
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.
Why do I need this exam?
Your PET/CT exam results may have a major impact on your physician’s diagnosis of a potential health problem, and if a disease is detected, how a treatment plan is developed and managed.
A PET/CT exam not only helps your physician diagnose a problem, it also helps predict the likely outcome of various therapeutic alternatives, pinpoint the best approach to treatment, and monitor your progress. If you’re not responding as well as expected, you can be switched to a more effective therapy immediately.
What should I expect when I arrive?
When you arrive, we will take a review of your history and any past exams.
For the PET portion of the exam, you’ll receive a radiopharmaceutical injection. 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 minutes to two hours) and only very small amounts are injected. In all cases, little or no radioactivity will remain in your body 10 minutes to six hours after injection.
For most studies, you’ll have to wait for
the radiopharmaceutical to distribute itself–
typically 30 minutes to an hour. During this time you will be asked to relax.
What will the scan be like?
You will lie on a comfortable, padded table. The table will move slowly through the tube-shaped PET/CT scanner as it acquires the information needed to generate diagnostic images.
You will be asked to lie very still during the scan because movement can interfere with the results. For the CT scan you will be asked to hold your breath for a few seconds to minimize body movements. During the scan, you might hear a humming noise, but you will not feel anything unusual. You may feel the table move while images are being taken at certain locations on your body. The technologist will monitor you during the exam.
The specific details of your upcoming exam will be explained fully by the technologist or your physician.
How long will all this take?
The PET/CT scan should last between 20 and 45 minutes. The exam procedure can vary depending on what you are being scanned for and what we discover along the way. Plan to spend two to three hours with us.
What happens after the exam?
You may leave us 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.
Following the scan, we will prepare the results for review by our radiologists, and then by your physician, who will discuss with you the results of the scan.
Are PET/CT exams safe?
Be assured that PET/CT exams are a safe and effective diagnostic procedure. The radiopharmaceuticals used in PET don’t 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’s pregnant.