These lectures were prepared by the authors for Seminars to be held on June 6, 1983, in St.Louis, Missouri, under the spon- sorship of the Radiopharmaceutical Science Council of the So- ciety of Nuclear Medicine . All manuscript? were refereed . Tracer kinetics and the modeling of physiological and bio- chemical processes in vivo are the focus of a contemporary di- rection in biochemical research. Recent advances in instrumen- tation (especially positron emission tomography and digital autoradiography) and parallel developments in the production of short-lived radionuclides and rapid...