Early perfusion computerized tomography imaging as a radiographic surrogate for delayed cerebral ischemia and functional outcome after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE To date, there is no immediate radiographic surrogate to quantify primary cerebral injury to identify patients at risk for delayed cerebral ischemia and poor clinical outcome after aneurysmal subarachnoid hemorrhage. Therefore, we investigated the relation of early cerebral perfusion-computerized tomography and clot volume with radiological events of delayed cerebral ischemia and clinical outcome in patients with aneurysmal subarachnoid hemorrhage. METHODS Data from 2 cohorts of patients (51 in main, 28 patients in control cohort) with aneurysmal subarachnoid hemorrhage, receiving computerized tomography and perfusion-computerized tomography scanning <12 hours after ictus, were included. A risk group model for functional outcome was developed on the basis of early mean transit time (MTT) and volumetric blood clot measurements. The relation of the risk group model with subsequent MTT, angiographic vasospasm, new cerebral infarction, and functional outcome was analyzed. Actual and predicted functional outcomes based on the risk group model were compared in the control cohort. RESULTS The risk group model correlated significantly with subsequent MTT measurements, cerebral infarction, and functional outcome. Odds for poor outcome were significantly higher in case of concomitant increase of early MTT and clot volumes, as opposed to exclusive early MTT or clot volume increase. For patients in the high- or low-risk groups, neurological outcome in the control cohort correlated significantly with predicted outcomes. CONCLUSIONS Assessment of early cerebral perfusion and intracranial blood clot may serve as a radiographic surrogate for delayed cerebral ischemia and functional outcome in patients with aneurysmal subarachnoid hemorrhage using risk group modeling.