Abstract
The in vivo counting system described accurately measures the absolute level of total body 59Fe, regardless of body size or isotope distribution. These results are accomplished by: (1) counting only the Compton scatter radiation emitted from the body rather than the full energy unscattered photons; (2) employing an optimum arrangement of multiple NaI crystal detectors; and (3) surrounding the subject with tissue equivalent plastic pellets. This counting system provides an accurate and efficient means for studying iron absorption or loss in man.