The Investigation of SAH page has been updated with new information about the higher sensitivity of multi-detector CT for the diagnosis of SAH. A normal multi-detector CT within 48-72 hours in a non very high risk patient, effectively excludes aneurysmal SAH.
Vincent A, et al. Sensitivity of modern multislice CT for subarachnoid haemorrhage at incremental timepoints after headache onset: a 10- year analysis Emerg Med J 2022;39:810–817. doi:10.1136/emermed-2020-211068