text: MRI may indicated in all patients with subarachnoid<unk>  if no lesion were found on prior angiography. MRI may be helpful in diagnosis of occult vascular lesions that can cause subarachnoid<unk>  and may include brain and spinal cord vascular malformations, tumors, and arterial dissection.
option_0: Subarachnoid hemorrhage MRI
option_1: Intracerebral hemorrhage MRI
option_2: Ischemic stroke MRI
option_3: Ischemic stroke CT
option_4: Hemorrhagic stroke MRI
option_5: Subarachnoid hemorrhage physical examination
option_6: Ischemic stroke ultrasound
option_7: Cerebral venous sinus thrombosis physical examination