title: On the role of modeling choices in estimation of cerebral aneurysm wall tension.
abstract: OBJECTIVE
  To assess various approaches to estimating pressure-induced wall tension in intracranial aneurysms (IA) and their effect on the stratification of subjects in a study population.
  
  
  METHODS
  Three-dimensional models of 26 IAs (9 ruptured and 17 unruptured) were segmented from Computed Tomography Angiography (CTA) images. Wall tension distributions in these patient-specific geometric models were estimated based on various approaches such as differences in morphological detail utilized or modeling choices made. For all subjects in the study population, the peak wall tension was estimated using all investigated approaches and were compared to a reference approach-nonlinear finite element (FE) analysis using the Fung anisotropic model with regionally varying material fiber directions. Comparisons between approaches were focused toward assessing the similarity in stratification of IAs within the population based on peak wall tension.
  
  
  RESULTS
  The stratification of IAs tension deviated to some extent from the reference approach as less geometric detail was incorporated. Interestingly, the size of the cerebral aneurysm as captured by a single size measure was the predominant determinant of peak wall tension-based stratification. Within FE approaches, simplifications to isotropy, material linearity and geometric linearity caused a gradual deviation from the reference estimates, but it was minimal and resulted in little to no impact on stratifications of IAs.
  
  
  CONCLUSIONS
  Differences in modeling choices made without patient-specificity in parameters of such models had little impact on tension-based IA stratification in this population. Increasing morphological detail did impact the estimated peak wall tension, but size was the predominant determinant.
authors.affiliation: Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Manasi
authors.initials: M
authors.lastname: Ramachandran
authors.forename: Aki
authors.initials: A
authors.lastname: Laakso
authors.forename: Robert E
authors.initials: RE
authors.lastname: Harbaugh
authors.forename: Madhavan L
authors.initials: ML
authors.lastname: Raghavan
mesh_terms: D002533:Cerebral Angiography; D020342:Finite Element Analysis; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008955:Models, Cardiovascular; D011312:Pressure; D014057:Tomography, X-Ray Computed