Bone blood flow shown with F18 and the positron camera

Development of the positron camera has made it possible to rapidly obtain pictures of the distribution of radioactive fluorine 18 in the living animal or human being. The distribution of F18 administered intravenously as fluoride ion is uneven in the normal skeleton. Furthermore, it is markedly altered in pathological conditions and accumulates at fracture sites, tumor sites, and in the lesions of Paget's disease. The initial uptake of fluoride in bone is dependent on the rate of delivery of the isotope to each bone (blood perfusion rate) and the extraction efficiency of that bone. Evidence is presented indicating the fluoride distribution in the skeleton is determined by differences in blood perfusion rate to the various bones rather than differences in extraction efficiency. We suggest that F18 distribution is an indicator of blood flow to bone.