title: Is aspect ratio a reliable predictor of intracranial aneurysm rupture?
abstract: OBJECTIVE
  This study was undertaken to assess the reliability of the aspect ratio (AR) (i.e., aneurysm depth to aneurysm neck) in predicting aneurysm rupture. It has been shown that the AR is a key factor in predicting intraaneurysmal blood flow and aneurysm rupture.
  
  
  METHODS
  Seventy-five patients with subarachnoid hemorrhage and multiple aneurysms were studied. The sizes of the aneurysms and their ARs were determined by examining the angiographic films. By comparing the difference between ruptured and unruptured aneurysms in the same individual, each patient in effect served as his or her own control. Each ruptured aneurysm was confirmed during surgery.
  
  
  RESULTS
  There were 75 ruptured and 107 unruptured aneurysms. The mean AR was 2.70 for ruptured aneurysms, compared with 1.8 for unruptured aneurysms. This difference between the ARs was statistically significant (P < 0.001). The difference in aneurysm sizes in the two groups also was significant (P < 0.001).
  
  
  CONCLUSIONS
  AR on its own is as reliable a variable as the size of the aneurysm for predicting aneurysm rupture.
authors.affiliation: Victor Horsley Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, Queen Square, London, England.
authors.forename: Ali
authors.initials: A
authors.lastname: Nader-Sepahi
authors.forename: Miguel
authors.initials: M
authors.lastname: Casimiro
authors.forename: Jon
authors.initials: J
authors.lastname: Sen
authors.forename: Neil D
authors.initials: ND
authors.lastname: Kitchen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011859:Radiography; D015203:Reproducibility of Results