Abstract
Regional cerebral blood flow, oxygen utilisation, fractional oxygen extraction, and cerebral blood volume were measured by positron emission tomography in thirty-two patients with internal-carotidartery occlusion. In most cases, any reduction in cerebral blood flow in the territory distal to an occluded carotid artery was matched to diminished cerebral metabolic demands. Cerebral blood flow was inappropriately low in only six patients, in whom regional oxygen utilisation was maintained by a compensatory rise in oxygen extraction ratio. The frequent finding of high cerebral blood volume distal to occluded vessels was consistent with a state of focal vasodilatation in response to diminished cerebral perfusion pressure. Analysis of the relation between cerebral blood flow, blood volume, and oxygen extraction ratio suggested that the reduction in cerebral perfusion pressure, and hence circulatory reserve; could be most reliably predicted by the ratio of cerebral blood flow to blood volume. By identifying those patients with carotid occlusion who are most compromised on haemodynamic grounds, combined measurement of cerebral blood flow and blood volume should be valuable in selection of candidates for extracranial-intracranial bypass surgery.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
