Investigation of choice for acute SAH is?

ANSWER: (C) CT scan REF: Sutton 7th ed p. 1779See APPENDIX-66 for "INVESTIGATION OF CHOICE"SUBARACHNOID HEMORRHAGEInvestigation of choice : non contrast CT scanIf scan fails : lumbar puncture to establish blood in CSFMost sensitive investigation for evaluating etiology : DSA of four vessels (carotids and vertebrals)Most common intracranial lesion after head injury: sub dural hematomaMost common cause of sub arachnoid hemorrhage: head traumaMost common cause of spontaneous SAH: ruptured aneurysmHEMATOMA ON CT SCAN:Epidural hematoma: biconvex or lens shaped, hyperdense (acute 2/3), hypodense ( chronic 1/3)Subdural hematoma: crescent, hyperdense (< 2 weeks), isodense (2-4 weeks ), hypodense (> 4 weeks)