Your body is primarily made up of oxygen, hydrogen, nitrogen and carbon. These are naturally occurring elements known as the "basic building blocks of life." In a PET study, these elements are made radioactive and then attached to other compounds used to fuel your body, like sugar or fats. This radioactive compound, or tracer, is then administered to you by an injection in your arm. There is no danger or side effects from this injection. Once these tracers are inside your body, the PET scanner is able to determine how organs and tissues are using them. The radioactive tracer used for this exam is FDG, or Fluorine-18 Deoxyglucose. After the PET images are obtained, CT images of the same areas are done. These two different image sets are then fused together and displayed. This new set of images allows the physician to view an area for both function and structure.
The combination of images greatly increases the physician's ability to specifically pinpoint areas of increased glucose.
What is a CT scan?
A computed tomography (CT) scan uses X-rays to make detailed pictures of structures inside of the body. The CT scanner sends X-rays through the body area being studied. All of the pictures are saved as a group on a computer. A CT scan can be used to study all parts of your body, such as the chest, belly, pelvis, or an arm or leg. It can take pictures of body organs, blood vessels, bones, and the spinal cord.
The PET/CT Advantage
There are tremendous benefits of having a combined PET/CT scan:
* Earlier diagnosis
* Accurate staging and localization
* Precise treatment and monitoring
With the high-tech images that the PET/CT scanner provides, patients are given a better chance at a good outcome and avoid unnecessary procedures. A PET/CT image also provides early detection of the recurrence of cancer, revealing tumors that might otherwise be obscured by scar tissue that results from surgery and radiation therapy, particularly in the head and neck.
In the past, difficulties arose from trying to interpret the results of a CT scan done at a different time and location than a PET scan, due to the fact that the patient's body position had changed. The combination PET/CT provides physicians a more complete picture of what is occurring in the body - both anatomically and metabolically - at the same time.