[Hemodynamic study of cerebral arteriovenous malformation by using 133Xe inhalation method]

We evaluated the hemodynamics of cerebral arteriovenous malformation (AVM) by measuring the regional cerebral blood flow (rCBF) with 133-Xe inhalation method in 20 cases. In addition, cerebrovascular CO2 reactivity were investigated in 12 cases among them by 5% CO2 inhalation (3 + 10 min). Twenty patients were 6 to 61 years of age (median 36.1 years) and 12 were male and 8 were female. Normal value of rCBF was obtained from 9 healthy volunteers. We measured rCBF using Novocerebrograph and evaluated by F1 & ISI value from 2 compartmental analysis. In order to evaluate CO2 reactivity, reactivity factor (RF) was calculated. (RF: CBF at 5% CO2-CBF at rest/PaCO2 at 5% CO2-PaCO2 at rest) AVM were divided into 3 types, namely superficial type in which the lesion was on the surface of the brain (5 cases), deep type in which the lesion was located deeply in the brain (13 cases) and dural AVM (2 cases). There were 2 types of feeding artery, that is, those via cortical branch or not, and we investigated the relationship between the angiographical findings and the types of AVM with reference to rCBF. In superficial type, all cases had feeding arteries via cortical branch. Two of them showed normal rCBF but 3 cases showed locally high and low value of rCBF on the lesion and low value around it. Angiograms showed hypovascular area coincident with this low value region. But a significant difference of mean CBF on both hemispheres was not detected in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)