Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography

Abstract

Initiation, growth, and rupture of cerebral aneurysms are caused by hemodynamic factors. It is extensively accepted that the cerebral aneurysm wall is assumed to be rigid using computational fluid dynamics (CFD). Furthermore, fluid-structure interactions have been recently applied for simulation of an elastic cerebral aneurysm model. Herein, we examined cerebral aneurysm hemodynamics in a realistic moving boundary deformation model based on 4-dimensional computed tomographic angiography (4D-CTA) obtained by high time-resolution using numerical simulation. The aneurysm of the realistic moving deformation model based on 4D-CTA at each phase was constructed. The effect of small wall deformation on hemodynamic characteristics might be interested. So, four hemodynamic factors (wall shear stress, wall shear stress divergence, oscillatory shear index and residual residence time) were determined from the numerical simulation, and their behaviors were assessed in the basilar bifurcation aneurysm.

Experimental evaluation of wall shear stress in an elastic cerebral aneurysm model

“…In addition, the oscillatory shear index (OSI) and relative residence time (RRT) are hemodynamic stress parameters additional to WSS and WSSG [24]. It has been reported that the maximum values of OSI and RRT are both more sensitive than WSS [25,26]. Therefore, we considered that the same tendency can be seen in this study.…”

“…Therefore, we considered that the same tendency can be seen in this study. However, because the shape of the cerebral aneurysm in this study differs from those of Yamazaki et al [25] and Abdollahi et al [26], there is a possibility that the trends in the sensitivity of RRT and OSI relative to WSS do not match. Therefore, the calculation of OSI and RRT is a future task.…”