A subarachnoid hemorrhage results from arterial bleeding into the subarachnoid space. The classic cause is usually rupture of an intracranial aneurysm. Subarachnoid hemorrhages can also occur traumatically, but they then often show a different pattern of blood distribution.
Imaging
The gold standard for imaging subarachnoid hemorrhages is CT imaging. However, subarachnoid hemorrhages can also be visualized on MRI.
