CFD and MRI studies of hemodynamic changes after flow diverter implantation in a patient-specific model of the cerebral artery

Abstract: Flow changes after flow diverter (FD) placement may be assessed by 4D phase-contrast MR-angiography (4D flow MRI) or simulated by computational fluid dynamics (CFD). However, cross-validation and future assessments with both approaches to take advantage of their individual strengths are required. In this study, we investigate the influence of a FD on intra-aneurysmal blood flow using both MRI experiments and CFD simulations. MR measurements were performed in a true-to-scale silicone model of a wide-neck saccular aneurysm of the distal internal carotid artery before and after FD deployment. An experimental setup, including a computer-controlled piston pump, was assembled to simulate pulsatile blood flow. For CFD studies, a virtual stenting technique was used to place a FD into the aneurysm model. Boundary conditions were applied according to MRI-measured flow data. A qualitative and quantitative agreement of velocity fields measured by CFD and MRI both before and after FD placement was demonstrated. The intra-aneurysmal flow reduction in the CFD results was 19%, while a reduction of 23% was measured by 4D flow MRI. Despite of the low spatial resolution, MRI was able to correctly determine the flow pattern in the aneurysm. The pre-treatment CFD simulation could be helpful in predicting the outcome of a FD treatment, while a post-interventional MRI could prove the desired treatment effect.Fil: Frolov, S. V.. Tambov State Technical University; RusiaFil: Sindeev, S. V.. Tambov State Technical University; RusiaFil: Kirschke, J. S.. Universitat Technical Zu Munich; AlemaniaFil: Arnold, P.. Universitat Technical Zu Munich; AlemaniaFil: Prothmann, S.. Universitat Technical Zu Munich; AlemaniaFil: Liepsch, D.. Munich University of Applied Sciences; AlemaniaFil: Balasso, A.. Ludwig Maximilians Universitat; AlemaniaFil: Potlov, A.. Tambov State Technical University; RusiaFil: Larrabide, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Grupo de Plasmas Densos Magnetizados. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Grupo de Plasmas Densos Magnetizados; ArgentinaFil: Kaczmarz, S.. Universitat Technical Zu Munich; Alemani