A pet scanner is:
• A large machine with a round, doughnut shaped hole in the middle
• Within this machine are multiple rings of detectors that record the
• energy from the radiotracer in your body.
Radiotracer: is a chemical compound in which one or more atoms have been replaced it can be used to explore the mechanism of chemical reactions
How it works:
• With ordinary x-ray examinations,
• an image is made by passing x-rays through the body from an outside source.
• detects this energy and with the help of a computer creates pictures offering details on both the structure and function of organs and tissues in your body.
A PET scan uses radiation, or nuclear medicine imaging, to produce 3-dimensional, color images of the functional processes within the human body.
The machine detects pairs of gamma rays that are emitted indirectly by a tracer (positron-emitting radionuclide), which is placed in the body.
The images are reconstructed by computer analysis.
Gamma rays: is a electromagnetic radiation of extremely high frequency and therefore high energy per photon.
How it works
• you will lie on a narrow table that slides into a large tunnel-shaped scanner.
• The PET detects signals from the tracer.
• A computer changes the signals into 3-D pictures.
• The images are displayed on a monitor for your doctor to read.
• focus on depicting(illustrating) physiologic processes within the body such as the levels of metabolism or other chemical activity
• Areas of greater intensity, called "hot spots," indicate where large amounts of the radiotracer have accumulated (been packed) and where there is a high level of chemical or metabolic activity.
• .Less intense areas, or "cold spots," indicate a smaller concentration of radiotracer and less chemical activity.