ABSTRACT
<p><b>OBJECTIVE</b>To investigate the biodistribution of (18)-NaF as an imaging agent for position emission tomography (PET) in rat models of osteoporosis.</p><p><b>METHODS</b>Osteoporosis was induced in 10 rats via injection with an excess of dexamethasone phosphate sodium, and the biodistribution of (18)-NaF in the rats was studied, with another 10 normal rats as the control group. (18)-NaF PET was also performed in 8 healthy volunteers, and the uptakes of (18)-F- in the bone tissues were measured.</p><p><b>RESULTS</b>Compared with the control rats, the osteoporotic rats showed significantly decreased (18)-F- uptake, especially in the femoral neck, lumbar vertebrae, the 7th rib and the tibia (P<0.05). Dynamic chest PET scanning in the volunteers revealed obvious (18)-F- uptake in the spine, ribs and humerus 20 s after injection of the imaging agent. (18)-F- uptake significantly increased with time in the bones, reaching the peak level 60 min after the injection, and whole-body PET at this point demonstrated obvious skeletal (18)-F- uptake, with high skeletal-to-muscle (STM) ratio that averaged 8.12.</p><p><b>CONCLUSION</b>(18)-NaF is an excellent skeletal imaging agent for clinical skeletal blood flow and metabolism measurements. The uptake of (18)-NaF has significant difference between normal and osteoporotic bone tissues, indicating the value of (18)-NaF PET for study of osteoporosis.</p>