A comprehensive type of imaging, PET-CT scans capture the metabolic and structural makeup of the body to diagnose various diseases. Learn about the science, the benefits, and the experience.

What are PET-CT scans?
Positron emission tomography–computed tomography, more frequently called PET-CT—is a type of nuclear imaging. As with nuclear medicine, PET-CT scans use small amounts of radioactive materials (called radiotracers) to diagnose and determine the severity of a variety of diseases at early stages, particularly cancers.

These radiotracers accumulate in diseased or inflamed areas of the body—and are then picked up by a special camera called a PET scan, capturing the body’s molecular activity. The PET scan is then laid over the CT scan to get a greater, more comprehensive look and a clearer, more precise diagnosis. Both of these scans happen simultaneously, combining cross-sectional views with glimpses into the body’s biochemical activity.

What should I expect from a PET-CT exam?
Luckily, a PET-CT procedure sounds more complicated than it actually is. The exam itself is relatively quick and painless. Though it’s common to be concerned about the radiotracers, the dosage of radiation is minuscule, and the benefits of the scan outweigh any potential risk.

Before the exam, you may be asked to fast (no food or water). Once you arrive, you will be given a dose of radiotracers intravenously—which is the most invasive part of the procedure. This is a quick prick and shouldn’t hurt, but it may feel cold. After about an hour or two (to give the radiotracers time to spread throughout the body), you’ll lie down on a table in the exam room. The table will move you headfirst into the donut-shaped machine to take the pictures. We ask patients to stay very still during the imaging process so we can obtain the highest quality pictures.

Throughout the exam, your technologist is there to answer any questions and make you feel as comfortable as possible.

What’s next?
The exam typically takes no more than an hour. When the technologist is done collecting images, you’ll be free to go. Over the next 2-5 days, the radiotracers will naturally leave your system. Be sure to drink a lot of fluids to effectively flush them out of your body.

Our radiologists will assess and interpret the images and send a report to your physician that same day. Please anticipate a call from your physician’s office with results and recommendations.