PET/CT is the most advanced medical imaging technique available today, combining Positron Emission Tomography (PET) with Computed Tomography (CT).

It combines the fine structural detail of CT with PET's ability to detect changes in cell function. This combination allows for earlier and more accurate detection of disease than either CT or PET alone. A PET/CT scan helps your physician diagnose a problem, determine the best approach to treatment or monitor your progress.

How PET/CT Works

Cancer cells grow at a very fast rate. Growing cells use glucose (sugar) as a primary source of energy. The faster cells grow, the more glucose is consumed. A form of glucose called FDG, which emits particles called positrons, is injected into the patient. The FDG molecules are consumed more in fast-growing cancer cells than in normal cells, resulting in concentrations of FDG, and positrons in areas of cancer. A PET/CT scanner detects where positrons are being emitted from within a patient and provides images that map the locations. PET FDG mapping is combined with a CT image’s structural detail in order to identify both the presence of disease and its precise location.

Procedure Information

After reviewing your history and prior to the exam, you'll receive a radiopharmaceutical injection. This is a radioactive tracer that must pass multiple quality control measures before it is used for any patient injection. You may be given oral contrast to allow visualization of your bowel.

For most studies, you will have to wait for the tracer to distribute itself — typically 45 minutes to one hour. You may be able to read, or listen to music until your scan begins. However, if we'll be scanning your brain, we will ask that you wait in a quiet, dimly lit room, without stimulating your brain by reading or talking.

For 4 hours before your test, do not eat or drink (except water). Do not even chew gum or mints.

Continue to take any medication prescribed to you by your physician. If you have been advised to take your medications with food, eat nothing more than a few soda crackers 4-8 hours prior to your exam.

Avoid caffeine, sugar, and heavy exercise for 24 hours prior to your exam.

If you have diabetes, discuss this with your physician and call the center staff 48 hours prior to your scan.

If you are or may be pregnant, discuss this with your physician.

You may leave immediately.

Your activity will not be restricted. You may drive if you wish, resume your normal diet, exercise and take your normal medications.

Your doctor will contact you about the results of your PET scan.


The PET Institute of Hampton Roads at 855-9700.