What is PET?
PET. Or Positron Emission Tomography, is a non-invasive, diagnostic scanner that takes powerful images of the human body’s biological functions. PET allows radiologists to see the biochemical changes in body tissue that are altered by disease. Traditional diagnostic imaging techniques, such as x-rays, MRI or CT scans show only the physical structure of the body. PET is unique because it can detect metabolic changes often before there is a change in gross anatomy. In many cases this allows the physician to find diseases in their very early stages, sooner than any other traditional techniques.

How does PET work?
The patient is injected with a simple sugar (glucose), which is chemically attached to a small amount of radiopharmaceutical; together this forms FDG. The PET scanner records where and how much the patient’s body is burning the FDG. A computer then reassembles the images in a full 3D view of the patients actual body functioning. PET enables the physicians to detect the location of the metabolic process (turning glucose into energy); which allows for non-invasive detection of any abnormal changes.


Upon arrival, the patient will be asked to complete any necessary paperwork for the registration process. The patient will be escorted with a technician to a prep area where the patient will receive an injection of FDG. The patient will then be asked to rest quietly for 30-50 minutes to allow for the FDG to be absorbed into their body.

The patient will then be asked to lie still on a long table which slides through the scanner. The scanner is about one foot wide and most patients are never placed completely through the scanner. If the patient can wear comfortable clothing containing no metal, they will not be asked to change into a hospital gown. The table will move slowly through the scanner as images are loaded onto the technician’s computer. The patient should not feel any discomfort from the scan or the injection (other than the initial injection, which is a typical I.V.). The scan takes approximately one hour to complete, once on the table.

Patients will then be escorted back to the waiting area for release. Patients may resume normal activities after the exam. Since the FDG is eliminated from your body through the kidneys, your body will void the remainder of any chemical naturally through urination. There is no risk of exposure to those around the patients themselves and no activity restrictions after the procedure.


  1. All patients MUST be NPO (No food or water) for at least 4 hours prior to their scheduled appointment. This allows for clearer, more precise imaging and lower percentage possibility of any inconclusive or false-positive readings. (Longer fasting will significantly improved scan quality.)
  2. Patient glucose levels must be below 200. Diabetic patients will have blood sugar levels checked prior to the procedure. If a diabetic patient has a blood glucose level greater than 150, the Radiologist will be consulted. It will be then decided whether or not to proceed with the procedure.
  3. No strenuous exercising 24 hours prior to the procedure.
  4. Medications with minimal sips of water are OK. However, if possible, medications should be postponed until after the scanning is complete. Consult your referring physician or Radiologist if there are any questions concerning your medications.
  5. Patients taking oral anti-hyperglycemic agents should NOT take them on the day of the exam and must fast. Any patient taking oral anti-hyperglycemic agents should request to be scheduled for morning examinations.
  6. Post-therapy studies should be delayed for four (4) to six (6) weeks following completion of therapy. (Increased FDG uptake too soon after treatment may reflect tumor damage or inflammatory reaction rather than residual disease.)
  7. Intravenous fluids containing glucose or TPN solutions must be discontinued four (4) hours prior to the study.


This study should not be performed in patients who are pregnant or are breastfeeding.

If there is any possibility of pregnancy, the patient should have a pregnancy test done prior to this test being scheduled. Please notify the facility if you think you may be pregnant or there is a chance you are pregnant.