Why SWI? The sensitivity of susceptibility weighted imaging in aneurysmal subarachnoid haemorrhage in the chronic phase.

In patients presenting in the subacute to chronic phase with a clinically suspicious history of previous aneurysm rupture but without convincing CT or spectrophotometry evidence, SWI can detect previous rupture. This can identify patients who could benefit from endovascular treatment and those who can safely undergo follow-up imaging.