Use of 3-fluoro-deoxyglucose for the assessment of cerebral perfusion and glucose transport. I. Theory.

A new model is described applying dynamic positron emission tomography (dPET) and 3-fluoro-deoxyglucose (3FDG) to the measurement of local cerebral perfusion and glucose transport across the blood-brain-barrier (BBB). The model takes advantage of 3FDG being practically not metabolized in brain and being transported back from tissue into the circulation. Simultaneous registration of tracer concentration in blood and tissue by dPET permits the in vivo determination of the Michaelis-Menten constant (K) and maximal velocity (V) for 3FDG and glucose transport across the BBB as well as the determination of local perfusion rate. Values obtained in normal cortex using this method were K = 6.3 mumol/g and V = 2.46 mumol/g min. Local perfusion rate ranged between 0.8 and 0.98 ml/min g.