Studies of skeletal tracer kinetics. I. Digital-computer solution of a five-compartment model of [18F] fluoride kinetics in humans
Journal of Nuclear Medicine
We have developed a new model of short-term fluoride kinetics in humans and have solved the model on a digital computer using the SAAM-25 program. The solution accords well with available data. About 60% of intravenously administered [18F] fluoride is taken up by bone. Evaluation of the rate constants of tracer egress from blood indicates that about 17% of the cardiac output is distributed to the skeleton. When the model was perturbed to simulate changes in systemic or skeletal blood flow, we
... al blood flow, we found that the system behaves in a nonlinear manner; even a five-fold increase in systemic or skeletal blood flow did not appreciably increase the amount of fluoride taken up by bone 1--2 hr later, the time when scans are usually made. A simulated increase in bone extraction rate, however, had a marked effect on bone-fluoride uptake. These findings suggest an important homeostatic role for bone in the regulation of blood calcium concentration and have considerable bearing on the interpretation of bone scans.