title: The effect of inlet waveforms on computational hemodynamics of patient-specific intracranial aneurysms.
abstract: Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms.
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA.
authors.forename: J
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Radiology, University at Buffalo, State University of New York, Buffalo, NY 14203, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Siddiqui
authors.affiliation: Toshiba Stroke and Vascular Research Center, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Mechanical and Aerospace Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA; Department of Neurosurgery, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA. Electronic address: huimeng@buffalo.edu.
authors.forename: H
authors.initials: H
authors.lastname: Meng
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000209:etiology*; D003198:Computer Simulation; D005260:Female; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D057446:Hydrodynamics; D002532:Intracranial Aneurysm / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D013314:Stress, Mechanical
keywords: Boundary condition; Computational flow dynamics; Inlet waveform; Intracranial aneurysm; Oscillatory shear index; Wall shear stress