In vivo functional imaging with SPECT and PET

Nuclear medicine methods permit the visualisation of a variety of metabolic and physiological processes all over the body. Although planar scintigraphy has been found useful for many questions, detailed spatial information about the diseased organ can only be obtained with tomographic methods. Dependent on the radionuclide involved, two different tomographic procedures are available: single photon emission computed tomography (SPECT) and positron emission tomography (PET). The first part of this paper describes shortly the historical development of these methods as well as their technical and methodological basics. To elucidate the large variety of possible applications, an overview of SPECT and PET procedures utilised in research as well as in clinical practice are presented. Furthermore, both methods are compared and their individual advantages are pointed out.