The first investigation of choice in a patient with suspectedsubarachnoid haemorrhage should be-

Ans. is 'a' i.e., Non contrast Computed Tomography o Most common cause is rupture of berry (saccular) aneurysm. Investigation of choice for acute subarachnoid hemorrhage is non contrast CT.o Blood in CSF on lumbar puncture is the hallmark of subarachnoid hemorrhage.o If CT scan fails to diagnose SAH and there is high index of suspicion, lumber puncture is the next investigation.o Investigation of choice for chronic SAH is MRI. Investigation of choice for determining the etiology of SAH is four vessels (both carotid and both vertebral) digital substraction angiography.