title: Computational fluid dynamics with stents: quantitative comparison with particle image velocimetry for three commercial off the shelf intracranial stents.
abstract: OBJECTIVE
  Validation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities.
  
  
  METHODS
  The recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density.
  
  
  RESULTS
  Velocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD-PIV matching in IA was found for intermediate porosity stents.
  
  
  CONCLUSIONS
  CFD reproduced fully PIV measurements in unstented and high porosity stented IAs. With low porosity stents, CFD reproduced velocity reduction and high velocities close to the neck, while a marked mismatch on sluggish flow was found at the dome. CFD was unable to match PIV with intermediate porosity stents for which hemodynamic transition occurred.
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bouillot
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Brina
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Rafik
authors.initials: R
authors.lastname: Ouared
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Hasan
authors.initials: H
authors.lastname: Yilmaz
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Karl-Olof
authors.initials: KO
authors.lastname: Lovblad
authors.affiliation: Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Farhat
authors.affiliation: Interventional Neuroradiology Unit, Service of Neuroradiology, University Hospitals of Geneva, Geneva, Switzerland Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Vitor
authors.initials: V
authors.lastname: Mendes Pereira
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D019295:Computational Biology / Q000379:methods*; D006801:Humans; D057446:Hydrodynamics; D010316:Particle Size; D012212:Rheology / Q000295:instrumentation / Q000379:methods*; D015607:Stents
keywords: Aneurysm; Blood Flow; Flow Diverter; Technology