The usefulness of PET is that, within limits, it has the ability to assess biochemical changes in the body. Any region of the body that is experiencing abnormal biochemical changes can be seen through PET. PET has had a huge impact on the clinical applications of neurological diseases, including cerebrovascular disease, epilepsy, and cerebral tumors. [5] PET is also important in drug research and development and can be used to study drug distribution, pharmacokinetics and pharmacodynamics. [6] In addition to cerebral tumors PET is used to detect and locate lymphogenic metastases, as well various other tumors. [7]
One of the most important functions of PET is its ability to model biological
and physiological functions in the body by detection and modeling of regional
concentrations of radioactivity in a particular organ. [8] It is now possible to
obtain improved anatomic localization of activity by overlaying or imprinting
the information from PET onto more detailed images of MRIs or CTs. [15] When
work with PET first began, the equipment consisted of devices such as radiation
scanners, multiple probes, and scintillation cameras. Carbon-11, Nitrogen-13,
and Fluorine-18 were first recognized as useful for biological studies soon
after these elements became available by cyclotron irradiation of stable
elements.