What is a PET-CT?

PET stands for Positron Emission Tomography, and PET-CT is the combination of two imaging techniques in one exam – a PET scan and a CT scan. The PET scan provides unique information about your body on a cellular level while a CT scan offers anatomic information. Overall, the PET-CT scan helps physicians better understand the exact location and extent of disease.  That information allows physicians to develop the best treatment plan for that specific patient.  PET-CT can reveal disease when CT or MRI is negative or inconclusive.

Why might my physician refer me for a PET-CT scan?

PET-CT can provide early diagnosis and accurate identification of whether and where the cancer has spread. During and after treatment, PET-CT can assess whether the treatment has been successful, by showing a decrease in glucose utilization by the tumor. PET-CT can be used for restaging, and provides early detection and localization of cancer recurrence. It can be critical in evaluation of patients in whom previous surgery or radiation therapy has resulted in scarring and distortion of normal anatomy, which hinder evaluation by CT or MRI. PET-CT also can be useful for cardiac patients and patients with epilepsy who are being considered for epilepsy surgery.

How do I prepare for my exam?

  • Bring recent x-ray studies (such as CT or MRI scan) obtained outside UVA hospital for the radiologist to compare directly to your PET-CT scan
  • Do not eat or drink, except plain water for 4-6 hours before the scan, i.e. no food, gum, mints, coffee (with cream or milk), etc. Black coffee or tea, both without sugar or cream/milk.
  • You may take any necessary medications that can be taken with water and are tolerated on an empty stomach, except for over the counter medications that contain sugar like cough syrup.
  • Diabetic patients will need to watch their diet and blood glucose closely for several days before the exam. It is important to keep sugar levels below 150.
  • No vigorous exercise or hard physical labor for 24 hours prior to your PET Scan appointment
  • Allow 2-3 hours for the PET-CT procedure. The actual scan time (lying on the imaging table) will be less than one hour, 1-1.5 hours for melanoma, or 30 minutes for brain. The standard exam varies depending on the type of study.
  • For oncology patients therapy itself may result in changes on the PET-CT in the area treated. The following are suggested for timing PET-CT scans after therapy:

No sooner than 4 weeks after radiotherapy. 
No sooner than 1-2 weeks after chemotherapy. 
No sooner than 4 weeks after surgery.

What happens when I arrive for my scan?

After arrival in the Radiology Department Reception area for your appointment, a technologist will ask about your medical history and explain the procedure.  The technologist will inject into a vein a very small amount of radioactive F-18 (FDG).  Following the injection, you will rest in a private room while the FDG distributes throughout your body and localizes in abnormalities. You will then be moved to the PET-CT scanner where the imaging procedure is performed while you lie comfortably on the scanner bed. The technologist will accompany you out of the imaging area at the end of your scan.

How long is the procedure?

It depends on the type of PET-CT scan your doctor ordered. In general please allow 2-3 hours for the entire visit. This includes time to prepare you for the scan and time in the scanner.

What about family or friends accompanying me to the appointment?

People who are not patients are unable to wait in the injection rooms or scan room.
Please make arrangements for childcare. We cannot be responsible for children left unattended.
Family/friends are welcome to remain in the waiting area or come back when the patient’s PET-CT scan is completed.

What if I am claustrophobic?

If you have had difficulty with MRI scans and feel the PET-CT may cause anxiety, please ask your physician to advise you. Claustrophobic patients may need to obtain a prescription from their physician before the appointment. If so, you will need to have a family member or friend accompany you to the appointment in order to drive you home after any sedative.

Will someone need to drive me?

If your doctor gives you medication to reduce anxiety during the exam, you will not be able to drive yourself home. The PET-CT will not affect your ability to drive.

Is PET-CT covered by insurance?

Medicare and most insurance cover PET-CT for many conditions. *Some insurance covers additional conditions for which PET-CT is useful. More >


For any questions or concerns

Contact the Radiology and Medical Imaging department at 434-924-9400.