Relationships between moment of monitored time-activity curves and regional cerebral mean transit time following common carotid administration of a non diffusible tracer.

By intravenous Radionuclide Angiography it is possible to estimate a whole path regional Arm-Brain mean transit Time as the first moment of monitored activity about injection time. This time is composed by an input mean transit time or transit time in the vein-inflow cerebral path and a circulation time within the monitored cerebral space. By evaluating this last by means of common carotid administration it was concluded that, although calculated by residue detection and not from outflow curves, this time is not far from regional cerebral mean transit time.