title: Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models.
abstract: OBJECTIVE
  The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms.
  
  
  METHODS
  Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations.
  
  
  RESULTS
  CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography.
  
  
  CONCLUSIONS
  The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.
authors.affiliation: Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: Anderson Chun On
authors.identifier: 0000-0003-2758-3253
authors.initials: AC
authors.lastname: Tsang
authors.affiliation: Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong.
authors.forename: Simon Sui Man
authors.identifier: 0000-0003-4336-1095
authors.initials: SS
authors.lastname: Lai
authors.affiliation: Departments of Mechanical Engineering, University of Hong Kong, Hong Kong.
authors.forename: Wai Choi
authors.identifier: 0000-0002-9002-8597
authors.initials: WC
authors.lastname: Chung
authors.affiliation: Departments of Mechanical Engineering, University of Hong Kong, Hong Kong.
authors.forename: Abraham Yik Sau
authors.identifier: 0000-0001-8842-9335
authors.initials: AY
authors.lastname: Tang
authors.affiliation: Department of Surgery, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: Gilberto Ka Kit
authors.identifier: 0000-0003-3147-3057
authors.initials: GK
authors.lastname: Leung
authors.affiliation: Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong.
authors.forename: Alexander Kai Kei
authors.identifier: 0000-0002-3958-8396
authors.initials: AK
authors.lastname: Poon
authors.affiliation: Departments of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong.
authors.forename: Alfred Cheuk Hang
authors.identifier: 0000-0002-8604-0219
authors.initials: AC
authors.lastname: Yu
authors.affiliation: Departments of Mechanical Engineering, University of Hong Kong, Hong Kong.
authors.forename: Kwok Wing
authors.identifier: 0000-0001-8763-2649
authors.initials: KW
authors.lastname: Chow
keywords: Endovascular procedures; Flow diverter; Intracranial aneurysm; Printing, three-dimensional; Ultrasonography