A study of regional cerebral blood flow and hemodynamics in cerebrovascular diseases by selective continuous infusion of Kr-81m.

A tomographic study of regional cerebral blood flow and hemodynamics was performed on 25 patients with cerebrovascular diseases by selective continuous infusion of krypton-81m (Kr-81m). Kr-81m single photon emission computed tomograms were superimposed on X-ray computed tomograms to assess topographically the perfusion of the entire brain. Study of cerebrovascular diseases using this method showed: (1) regional cerebral blood flow change; (2) perfusion distribution change; (3) the route by which blood reached the brain or the obstructed artery proximal to the circle of Willis; (4) development of a collateral system and its actual function; and (5) efficacy of surgical bypass after extracranial-intracranial anastomosis. This method is especially useful in hemodynamic assessment in patients with ischemic cerebrovascular disease.