Intracranial aneurysms: looking beyond size in neuroimaging: the role of anatomical factors and haemodynamics

Some cerebral aneurysms are diagnosed incidentally; others may present symptoms due to the pressure exerted on surrounding structures, and local processes such as inflammation. They are, however, frequently diagnosed after a subarachnoid hemorrhage (SAH), following aneurysm rupture. SAH carries a high mortality and morbidity, and incidence of 6–8/100,000 (1). Lifetime cost-per-year of survival following SAH is 3× as high as elective surgery or endovascular treatment of patients with an unruptured aneurysm (UA) (2). Thus, estimated risk of rupture is a key factor in deciding how to treat UA.