Positron Emission Tomography (Pet) in Medical Imaging

Abstract

Positron Emission Tomography (PET) is a radiotracer imaging technique, in which tracer compounds labelled with positron-emitting radionuclides are injected into the subject of the study. One of the prime reasons for the importance of PET in medical research and practice is the existence of positron-emitting isotopes of elements Such as carbon, nitrogen, oxygen and fluorine, which may be processed to create a range of tracer compounds which are similar to naturally occurring substances in the body. The largest area of clinical use of PET is in oncology, cardiology and neurology. The most widely used tracer in oncology is (18)F-fluoro-deoxy-glucose (EDG) which follows a similar metabolic pathway to glucose in vivo, except that it is not metabolised to CO, and water, but remains trapped within a tissue. This makes it well-suited to use as a glucose uptake tracer. This is of interest in oncology because proliferating cancer cells have a higher than average rate of glucose metabolism. (11)C-methionine is also used in oncology, where it acts as a marker for protein synthesis. In our country, one of the experimental channels Of TESLA Accelerator Installation will be used for production Of long-living positron emitters (e.g. (124)I, (86)Y, (76)Br, (64)Cu) and alpha emitters (e.g. (211)At and (149)Tb).