Positron emission tomography: PET

To allow non-invasive radiotracer studies in human, the emitted radiation must be detected outside the body, PET technique employs tracers labeled with short-lived positron emitting radionuclides that produce externally detectable two anti-parallel gamma photons by collision with an electron, By computerized reconstruction, cross section images of the distribution of the radioactivity can be created. The short half-lives of the radionuclides minimize radiation-exposure and allow tht repetitive PET-investigations within short time intervals, The high specific radioactivity makes it possible to work with small concentration of the tracers. PET has become increasingly important in biological and medical research, The development of new synthetic methods is eagerly desired to produce new tracers labeled with positron emitting radionuclides.