Dynamic quantitative assessment of cortical blood flow.

Dynamic real time quantitative assessment of cortical blood flow is feasible with a thermal diffusion flow probe. The probe consists of a Peltier stack that creates a thermal gradient. The thermal gradient has been calibrated against Xe133 clearance for fast flow. Rapid changes in flow induced with pharmacologic agents, changes in perfusion pressure, or vascular manipulation are readily apparent. This technique is useful for intraoperative assessment of cortical blood flow and may prove useful in postoperative monitoring.