What is a PET?

A PET (Positron Emission Tomography) is a type of nuclear medicine imaging that uses small doses of radioactive material called radiotracers to help diagnose or evaluate response to treatment for a variety of conditions. Generally administered through an IV, radiotracers accrue in metabolically active areas such as tumors or regions of inflammation. These regions will appear brightly colored on an exam, illustrating to Radiologists where disease is present. As nuclear medicine exams can trace molecular activity, PET scans can detect changes or abnormalities in its earliest states.

What are PET scans used for?

This imaging procedure is commonly used to:

  • help stage and diagnose cancers
  • assess the effectiveness of treatment
  • evaluate brain abnormalities such as tumors, memory disorders seizures or other central nervous system disorders
  • identify effects of a heart attack or areas of the heart that may need an angioplasty or bypass surgery
  • record normal human brain & heart function


PET technology is combined with CT, to produce a more comprehensive visualization of diseases. Almost all PET exams are performed on these combined PET/CT scanners. As PET scans measure the body’s metabolic activity of cells, it helps doctors evaluate organ and tissue functionality. CT imaging uses x-ray equipment along with a contrast agent to provide doctors with details on organ structure. This information from separate studies correlated and interpreted into one image provides greater precision and diagnostic accuracy.

What to expect during the exam?

Before the scan, you will have your blood sugar checked and an IV started to inject the radioactive glucose. There is a one-hour resting period in a private room following the injection. PET/CTs are performed using the same machine, therefore, similar to a CT, patients are positioned to lie on their back on the examination table where they will then be moved through a “doughnut shaped” machine and images are captured. A technologist will be with you through the duration of your scan. You will be advised to not to eat or drink for several hours before the scan. Clear liquids are permitted.

Once your PET scan is complete, interpretations are performed by board certified, subspecialty trained radiologists. Imaging reports will be sent to your referring provider who will then contact you with your results or schedule a follow-up consultation.