What is the gold standard diagnostic test for SAH within the first 6 hrs and beyond 6 hrs support ur answer with evidence
"subarachnoid hemorrhage" AND "CT angiography" AND "lumbar puncture" AND diagnosis
"subarachnoid hemorrhage" AND "xanthochromia" AND "lumbar puncture"
"subarachnoid hemorrhage" AND "computed tomography" AND sensitivity diagnosis
"subarachnoid hemorrhage" AND "six hours" AND "CT scan" AND sensitivity