title: Rupture Resemblance Score (RRS): toward risk stratification of unruptured intracranial aneurysms using hemodynamic-morphological discriminants.
abstract: OBJECTIVE
  We have previously developed three logistic regression models for discriminating intracranial aneurysm rupture status from 119 aneurysms based on hemodynamic-morphological parameters. In this study we exploit their use as a tool for predicting the risk of rupture of aneurysms with a defined Rupture Resemblance Score (RRS).
  
  
  METHODS
  We collected three-dimensional images of 85 consecutive aneurysms, applied the three regression models and compared model performance at predicting rupture status against anecdotal metrics (aneurysm size and aspect ratio). We then reinterpreted the model-predicted probability as RRS, where the higher the score the closer the resemblance to previously known rupture components, and applied the RRS prospectively to four unruptured aneurysms with borderline treatment decisions.
  
  
  RESULTS
  All three models yielded excellent sensitivity (0.78-0.83) and specificity (0.78-0.84) at a cutoff score of 50%, whereas aneurysm size and aspect ratio showed poor sensitivities (0.28 and 0.33, respectively). Lowering the cutoff score to 30% improved sensitivity to 0.90. The RRS identified most of the ruptured aneurysms and also some unruptured ones that closely resembled ruptured aneurysms hemodynamically and/or morphologically. The prospective application of the RRS to unruptured aneurysms shows that it could provide additional insights for treatment decisions.
  
  
  CONCLUSIONS
  Previous regression models based on hemodynamic-morphological parameters are able to discriminate rupture in a new cohort in the same population. A higher probability of rupture is associated with larger size ratio, lower normalized wall shear stress and higher oscillatory shear index. The RRS could potentially stratify rupture risk and assist in treatment decision-making for unruptured aneurysms.
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Department of Biostatistics, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Jihnhee
authors.initials: J
authors.lastname: Yu
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, Upstate Medical University, Syracuse, New York, USA.
authors.forename: Hoon
authors.initials: H
authors.lastname: Choi
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Dolan Fox
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Snyder
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Elad I
authors.initials: EI
authors.lastname: Levy
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Radiology, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Adnan H
authors.initials: AH
authors.lastname: Siddiqui
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Meng
mesh_terms: D017542:Aneurysm, Ruptured / Q000145:classification* / Q000175:diagnosis*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000145:classification* / Q000175:diagnosis*; D008297:Male; D011446:Prospective Studies; D018570:Risk Assessment
keywords: Aneurysm; Blood Flow; Hemorrhage; Stroke