Observation of Cerebral Blood Flow in Intracranial Arteriovenous Malformation

By means of two techniques, Kr 85 clearance technique by Lassen et al and nondiffusible RI injection technique by Olendorf et al, cerebral circulation was studied in 4 patients with intracranial arteriovenous malformation. Since the clearance rate of Kr 85 from the brain depends upon the blood flow washing out the radioisotope from the tissue, the value obtained with this technique could represent the effective blood flow; it referes to the blood flow which traverses capillaries and is engaged in the exchange of nutrients and metabolites. On the other hand, the dilution curve obtained by external tracing of the radiaactive bolus traversing the brain, reflects the blood flow which passes through the intracranial vascular bed, since nondiflusible indicator (RISA was used in most cases) which does not move across the blood-brain barrier, remains within vessels.