An intravenous 133xenon clearance technique for measuring cerebral blood flow.

An intravenous 133Xe clearance technique for measuring cerebral blood flow (CBF) is described. Results obtained compared well with those using the intracarotid 133Xe technique. The reproducibility of the method was checked by repeating measurements within a few hours in 14 patients, when no significant overall change occurred, and after some days in 23 patients when a mean fall in flow of 8% was observed. CBF was measured in 52 control subjects. The mean fast component flow (Ff) was 68.6 ml/100 g/min (SD 11.3). No difference between the two hemispheres was found. Flow was confirmed to be higher anteriorly in the cerebral hemispheres. A significant inverse correlation was found between CBF and age.