title: Computational Fluid Dynamics modeling of contrast transport in basilar aneurysms following flow-altering surgeries.
abstract: In vivo measurement of blood velocity fields and flow descriptors remains challenging due to image artifacts and limited resolution of current imaging methods; however, in vivo imaging data can be used to inform and validate patient-specific computational fluid dynamics (CFD) models. Image-based CFD can be particularly useful for planning surgical interventions in complicated cases such as fusiform aneurysms of the basilar artery, where it is crucial to alter pathological hemodynamics while preserving flow to the distal vasculature. In this study, patient-specific CFD modeling was conducted for two basilar aneurysm patients considered for surgical treatment. In addition to velocity fields, transport of contrast agent was simulated for the preoperative and postoperative conditions using two approaches. The transport of a virtual contrast passively following the flow streamlines was simulated to predict post-surgical flow regions prone to thrombus deposition. In addition, the transport of a mixture of blood with an iodine-based contrast agent was modeled to compare and verify the CFD results with X-ray angiograms. The CFD-predicted patterns of contrast flow were qualitatively compared to in vivo X-ray angiograms acquired before and after the intervention. The results suggest that the mixture modeling approach, accounting for the flow rates and properties of the contrast injection, is in better agreement with the X-ray angiography data. The virtual contrast modeling assessed the residence time based on flow patterns unaffected by the injection procedure, which makes the virtual contrast modeling approach better suited for prediction of thrombus deposition, which is not limited to the peri-procedural state.
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Vali
authors.affiliation: Department of Neurosurgery, University of Arkansas for Medical Science, AR, USA.
authors.forename: Adib A
authors.initials: AA
authors.lastname: Abla
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, CA, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
authors.affiliation: Department of Radiology and Biomedical Imaging University of California, San Francisco, CA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Saloner
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Mechanical Engineering, University of Wisconsin, Milwaukee, WI, USA. Electronic address: vrayz@mcw.edu.
authors.forename: Vitaliy L
authors.initials: VL
authors.lastname: Rayz
mesh_terms: D001488:Basilar Artery / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D002532:Intracranial Aneurysm / Q000503:physiopathology*; D008955:Models, Cardiovascular; D066230:Patient-Specific Modeling
keywords: Cerebral aneurysm; Image-based computational modeling; Patient-specific CFD; Surgical planning; X-ray angiography