For more information about PET-CT scans, visit PETNET Solutions.


A PET-CT scan combines two state-of-the-art imaging technologies, PET, or positron emission tomography, a nuclear medicine exam, and CT, or computerized tomography, an X-ray exam, into a single scan. A PET-CT scan merges both technologies to quickly provide a high-quality image of both body form and function.

Reasons for the procedure

PET-CT imaging differs from other examinations in that it provides a complete picture of body structures and how they are functioning. PET-CT images can help physicians detect, diagnose and determine and evaluate treatment for diseases such as cancer, heart attack and neurological disorders. Rapid, more accurate imaging improves the ability to find and treat problems early on, when treatment can be most effective.

Risks of the procedure

There is no discomfort, very low radiation exposure, and no reported adverse reactions associated with a PET-CT scan.

How is it done?

Before the exam, imaging staff perform a finger-stick to test your glucose level, and will then give you an injection of a small amount of radioactive glucose (sugar). You will rest comfortably for close to an hour while the glucose is distributed throughout your body. You are then welcome to make a trip to the restroom before a technologist assists you to the scanner.

You will lie on your back on a scan table and be made as comfortable as possible. The table will slide slowly into the middle of the scanner. You will receive the CT portion of the scan first, followed by PET. It is important that you remain still throughout the scan. You may be asked to hold your breath for several seconds while the CT scan is performed. The whole scan will take 20-40 minutes to complete.

The radioactive substance is short-lived, so it is very important to arrive on time and receive the glucose solution at the scheduled time. Please allow 2-1/2 to 3 hours from check-in to finish.

What to expect

Preparation before the procedurePlease follow all instructions provided by your doctor. In addition:

  • Inform your doctor if you think there is a possibility you are pregnant, if you are nursing, or if you have had recent radiation therapy treatment
  • If you have diabetes or kidney disease and/or are taking glucose-lowering medication, be sure to tell your doctor

The day before your exam

For the entire day prior to your PET-CT scan do NOT eat sugars or carbohydrates.
Avoid the following items:
Bread, pastry, cereal, potatoes, pasta, rice, soy products,
Fruits (no tomatoes), desserts, cakes, flavored yogurt,
Soft drinks, tonic water, juices, beer, alcoholic beverages.

You may have: meat, vegetables, eggs, cheese and milk.

Please, no vitamins, strenuous exercise, caffeine or tobacco products the day before or the day of you exam.

Morning appointments: Do not eat or drink (except water) after midnight.

Afternoon appointments: Do not eat or drink (except water) after 6 a.m. An early morning breakfast of protein only, NO sugars or carbohydrates.

Day of appointment

  • Drinking water before the exam is encouraged, but ONLY water
    • Anything other than water can adversely affect exam quality
  • All necessary medications may be taken with water
  • The PET-CT room is chilly: please wear warm clothing, such as a sweat suit, with no metal (i.e., zippers, etc)
  • You may wear your hearing aid, glasses and dentures to your appointment

Please note: If you scheduled your exam yourself, you must present the signed order from your physician at your appointment to receive the scan.

Who interprets the results and how will I get them?

The radiologist will interpret the scan and prepare a report for your doctor. Your doctor should contact you with the test results.

After the procedure

You may resume your normal diet and activities immediately following your procedure. All traces of the radioactive glucose leave you system over the course of a few days. Drinking plenty of water will help you flush it from your system more quickly.