diagnostic imaging and radiology

PET / CT Scan

​Combining the power of PET & CT

PET is an acronym for positron emission tomography. PET is a test that uses special imaging cameras and a radioactive type of sugar to produce pictures of the function and metabolism of cells in the body.

CT stands for computerized tomography. CT is an X-ray test that generates a detailed view of the anatomy or structure of organs and tissues in the body. The CT scan can show the dimension of vessels, lymph nodes and organ systems.

A PET/CT can depict both technologies using a single machine. It provides a picture of function (PET), a picture of anatomy (CT), and a merged picture of both the body's metabolism and structure.

Preparing for your PET/CT exam

There are strict preparation guidelines for all patients — especially diabetics — regarding what you can eat or drink before your exam. If you have questions regarding your preparation, contact the scheduling department for instructions.


  • Do not eat or drink anything except water six hours prior to your exam.
  • Take your regularly scheduled medicine before arriving (if you can tolerate it on an empty stomach).
  • Avoid rigorous activity for 24 hours before your exam.
  • Dress warmly and comfortably.
  • If you are diabetic, the scheduling department or nuclear medicine tech will provide you with detailed instructions about when to eat and take your insulin, depending on the time of your appointment. It is critical that you follow all preparation guidelines and ensure your glucose levels are within normal limits or the exam will need to be rescheduled.

Important: Please make every effort to keep your appointment. If you must cancel or reschedule, notify our office at least 24 hours in advance. The FDG (sugar water with a radioactive tracer) used for your scan is prepared specifically for you and will have to be discarded if you fail to keep your appointment.

Consult your physician prior to your PET/CT scan if:

  • You are or may be pregnant
  • You are allergic to any food or drugs
  • You are currently being treated for an infection
  • You are unsure if you should take your medications
  • You have had recent radiation therapy

What to Expect

During the exam, you will receive a small injection of FDG (sugar water with radioactive tracer). You will sit or lie down on a comfortable chair or bed for 30-90 minutes while the FDG travels throughout your body.

After this time, the technologist will assist you to the scanner. The CT portion of the exam is completed first, followed by the PET portion. You may be asked to hold your breath for several seconds while the CT scan is performed. It is important you don't move for the duration of the exam.

The length of the exam is determined by your height and area of the body being scanned. When the total scan is finished, the computers will produce images for the radiologist to review.

Once the total scan has been performed, you may resume daily activity. Even though the FDG will quickly leave your body, you can expedite the process by drinking plenty of water after your scan is complete.

The reading physician will contact your referring physician to communicate all pertinent information from your scan. Then your referring physician will contact you to share the results.

Benefits of PET/CT

PET/CT helps physicians diagnose, stage and treat cancer with more accuracy than ever before.

The exam can provide answers to the following critical questions:

  • Where is the tumor?
  • Is it spreading?
  • How large is it?
  • What is the optimal therapy?
  • Is the therapy working?
  • Is there a recurrence?

Other potential benefits include:

  • Improves diagnostic confidence for patients who have or may have cancer
  • Reduces the need for invasive procedures like biopsy or surgery
  • Helps avoid the "wait and see" method often used to monitor potential disease
  • Monitors patients' response to treatment to ensure the treatment is working

Prostate-specific membrane antigen (PSMA) scans

A PSMA PET/CT scan is used to detect prostate cancer anywhere in the body. It will help your provider determine the next steps of your treatment.

Preparing for PSMA PET/CT scans

The nuclear medicine tech will call you the day before to confirm your appointment. It's important that you take this call so your appointment will not be cancelled.

On the day of your scan:

  • Eat as you normally would
  • Drink water to be well-hydrated before the scan
  • Take your normal medications
  • Bring a list of your current medications and your insurance card
  • Wear warm, comfortable and metal-free clothing

Although the time needed for the scan varies, plan to spend about two hours at your appointment. After you are checked in, you'll receive an IV line in your arm with a low-dose radioactive tracer. When it's time for your imaging, you'll be asked to go to the bathroom and then you'll lie on the scanner table. You'll hold this position for up to 40 minutes, so let the staff know if you are uncomfortable or need to shift before the scan starts.

After the scan, you'll be provided with post-scan instructions and may resume your normal activity level. Drink plenty of water and urinate as frequently as possible to help clear your body and reduce radiation exposure.

Your provider will follow up with you regarding the results of your scan.