Subarachnoid Hemorrhage

History: 60 year old male with severe headache.

Subarachnoid hemorrhage: Axial CT scan of the head without contrast reveals multiple regions containing hyperdense material layering particularly within the sulci of the right frontal lobe and left parietal lobe.

This is a case of subarachnoid hemorrhage. Typically sudden onset non-traumatic subarachnoid hemorrhage is the result of a ruptured cerebral aneurysm, however, in this case the distribution of subarachnoid hemorrhage is not typical for a ruptured aneurysm, and may be related to other causes such as supratherapeutic anticoagulation.