MY CONTENT

This systematic review showed a very heterogeneous literature, with 140 studies using 60 different nomenclatures and 21 different thresholds to define cerebral vasospasm, and 5 interobserver studies reporting a wide range of reliability. Research on cerebral vasospasm would benefit from standardization of definitions and thresholds. Dichotomized decisions by experienced readers are required for the reliable angiographic diagnosis of cerebral vasospasm.