Interobserver agreement and predictive value for outcome of two rating scales for the amount of extravasated blood after aneurysmal subarachnoid haemorrhage

Abstract
In patients with SAH the amount of extravasated blood on the initial CT scan is related with delayed cerebral ischemia and clinical outcome. We investigated the interobserver variation of the Hijdra and Fisher scales for the amount of extravasated blood and the predictive values of these scales for delayed cerebral ischemia and outcome.