Abstract
In this presentation, a CBF study was performed by intracarotid infusion of Kr-81m in seven patients who underwent STA-MCA anastomosis for cerebral vascular occlusive disease.
In these patients, we studied especially the cerebral perfusion through extracranial-intracranial anastomosis by infusion of Kr-81m into the external carotid. We presented the procedure and results in these patients.
In each of the patients, the internal and external carotid were selectively cannulated by a teflon catheter which was connected to the output of the Kr-81m generator. The input of the generator was connected to a Harvard pump with 50ml syringe containing 5% glucose solution which was infused at the rate of 7. 5ml per minute. Infusion of the solution consequently milked Kr-81m from the generator into the carotid continuously at the same rate. The cerebral Kr-81m image which represented the perfusion, was depicted with the 5000-holes collimeter and gamma camera, and recorded on magnetic tapes. After completion of the CBF study, angiography was performed to confirm the patency of the anastomosis.
In these patients, the patency of the anastomosis and the degree of the extracranial-intracranial cross-perfusion were clearly observed by the external carotid infusion of Kr-81m.
Comparing with Xe-133 clearance method, this examination has a disadvantage that the absolute CBF values are not measured, but has an advantage that it is readily repeated immediately one after another because of its very shorthalf-life of 13 seconds. Thus this method has proven to be beneficial in studying the continuous CBF changes following hyperventilation or CO2 inhalation.
