What is PET-CT?

PET-CT is an advanced, innovative new tool that combines two scanners - Positron Emission Tomography (PET) and Computed Tomography (CT) - into one. It represents a major advance in imaging technology and improved patient care.

PET scanning provides critical information about the body's metabolic functions. It is based on chemical and physiological changes in the metabolism, as opposed to changes in physical structure of internal organs. Pet scans can also provide critical information about the metabolic function of cancer cells and can detect very small tumors, but cannot pinpoint the exact location of these tumors.

CT scanning can provide this anatomic information. The combination PET-CT scan enhances image quality and requires about 25 percent less scan time than PET scans alone. This new system gives doctors a better way of detecting and diagnosing conditions like cancer earlier and more accurately. This also increases the patient's chances for a better outcome.

The PET-CT scanner is a machine consisting of two large rings with an open area between them. This gives the patient the ability to see around them. The patient will be lying on a cushioned table, which moves slowly into the machine, allowing it to get the information needed to create the images.

How should I prepare for the PET-CT scan?
You should dress warmly in comfortable clothes for your PET-CT scan. The following is a basic list of patient preparations for all PET-CT exams; however you might receive additional instructions based on the type of study ordered by your physician. People with diabetes will also receive special individual instructions. Following these instructions will greatly increase the chances of completing your exam and improve the quality of your PET-CT.

The night before your exam:

Eat a light dinner.
Shower the night before, not the day of your exam.

The day of your exam:

No food 6 hours before your exam.
No chewing gum.
No smoking.
No chewing tobacco or snuff.
No caffeine, including tea, coffee, etc.
Take all medications routinely except for sedatives.
Do not exercise. Stay calm, quiet, and relaxed.
Drink 16-24 ounces of water.
Arrive 30 minutes before the exam.
No family members are allowed in with you during the exam.

What will I experience during a PET-CT scan?

When you arrive, we will take a short medical and check your blood sugar level. We'll ask you to go to the restroom to empty your bladder. Before the scan we will inject a radioactive tracer into your body through a vein in your arm. This tracer is a compound of complex sugars mixed with a short-lived radioisotope. After the injection you will rest in a comfortable, quiet environment for about 45 minutes while the radioactive tracer travels through your body and is processed by the organs being evaluated. You will then be asked to lie still on the imaging table that will pass slowly into the scanner. The tracer in the your bloodstream gives off energy that will be detected by the PET-CT scanner. These signals are then recorded and reassembled into actual images by a computer. This part of your exam will take about 30 minutes. A radiologist will then interpret these images and send a report to your physician.

You can expect your entire visit for your PET-CT scan to last about 2 hours. When your scan is complete you will be asked to drink plenty of fluids to flush your system. You should feel fine, however, as there have been no documented side effects from the injected material.

Last updated December 27, 2007