What can I expect during a positron emission tomography (PET) scan?

John A. Chabot
Endocrinology Diabetes & Metabolism

Before the PET scan, you will be given an injection of the radioactive substance and asked to rest for about an hour. Similar to a CT scan, you will then be asked to lie on a bed which will move slowly through a doughnut-shaped ring. As with all scans, it is important that you do not move during the test. The entire PET scan process, from injection to completion, can take up to 3 hours.

The PET scan is a relatively safe procedure. Most people experience no side effects due to the radiolabeled material. Allergic reactions to the radiolabeled material can occur, but are extremely rare. For most types of cancer, PET scans can only show tumors that are at least 1 centimeter in size.

Continue Learning about Diagnostic Procedures

Diagnostic Procedures

Diagnostic Procedures

Allergy tests, echocardiograms, biopsies, semen analysis and spinal taps are just a few of the medical diagnostic procedures that are performed on patients diagnose diseases and conditions. These classification procedures do not i...

nvolve x-ray imaging or a surgical procedure, but, involve taking measurements and samples of fluids, tissues and cells. Learn more about diagnostic procedures from our experts.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.