Cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking after acute stroke in pigs - Comparison with [O-15]H2O positron emission tomography

Background and Purpose-Early and accurate assessments of cerebra) ischemia allow therapy to be tailored to individual stroke patients. We examined the feasibility of using a novel method for measuring cerebral blood flow (CBF ) of ischemic tissue based on MRI after middle cerebral artery occlusion (M CAO, Moreover, the regional correlations between CBF and cerebral blood vol ume (CBV) were investigated in the regions with acute ischemic stroke. Methods-CBF and CBV were measured before and after MCAO or reperfusion by p ositron emission tomography (PET) in 13 pigs. Just after the PET scans, CBF and CBV were measured by MR bolus tracking and were compared with results obtained by PET at 6 hours after permanent MCAO or reperfusion, The infarct ion was verified histologically. Results-The MR method yielded parametric CBF and CBV maps with tissue contr ast in good agreement with parametric PET images, which demonstrated hypope rfused and hyperperfused areas after MCAO or reperfusion. Both MRI and PET technology showed that CBF values below 60% of the contralateral value indu ced a reduction of CBV, which committed the tissue to infarction. Conclusions-The novel MR method provides accurate measurement of CBF and CB V in acute stroke and hence gives useful information for planning the appro priate therapeutic intervention.