PET Technology

PET – General Description

PET, or Positron Emission Tomography, is a non-invasive imaging technique used both for clinical diagnostic detection of disease in patients as well as for medical research purposes. PET uses radioactive tracer compounds (radiopharmaceuticals) that are injected into the patient or subject. The patient is placed in a PET scanner which detects and images the distribution of the radioactive tracer compound in the body. Depending upon the specific radioactive tracer compound used, these images can be used to detect and diagnose a number of different diseases and disease states. Whereas MRI and CT technologies are more capable of defining anatomical parameters of a disease, PET technology is uniquely suited to provide information on metabolic and physiologic functions within the tissue. Since the PET scanner can measure the uptake in tissues of PET radiopharmaceuticals that trace specific biochemical pathways, PET scans often provide unique and complementary information to anatomical imaging that helps to differentiate diseased tissue from normal tissue. PET scans are able to detect small molecule probes in sufficient sensitivity to perform non-invasive assessment of biochemical pathways of the body's most important molecules, such as glucose, fatty acids, amino acids, and neurotransmitters. Because biochemical activity is often changed dramatically in diseased tissues, PET scans can provide a more specific and sensitive detection of disease, oftentimes before any anatomical change occurs. No other imaging technique can see inside the workings of the cell like

 

PET Technology

PET Radiopharmaceuticals
The starting point for producing a PET radiopharmaceutical is the production of a suitable positron-emitting radionuclide. All of the radionuclides used in PET are short-lived, and the common nuclides are Carbon-11, Nitrogen-13, Oxygen-15, and Fluorine-18. These radionuclides are produced by the bombardment of stable nuclides with an ion beam in a particle accelerator, such as a cyclotron. A trace amount of the radionuclide is then incorporated into a specific imaging compound during its chemical synthesis.

Links:

http://www.petscan.org/frames_whatispet.html

http://www.ami-imaging.org