Generalized versus Specific Boundary Conditions for CFD in vertebral-basilar artery

The application of computational fluid dynamics simulation to hemodynamic prediction is now getting a boost. Boundary conditions generalized from previous articles have been applied in these studies because of the lack of patient-specific data. We compared five types of generalized flow rates in vertebral and basilar arteries with specific flow rates. The comparison between generalized and specific boundary conditions were performed to improve the use of generalized data. Twenty patient-specific models were applied in simulations using generalized and specific boundary conditions. The results turned out that wall shear stress (WSS) magnitude from both boundary conditions showed large differences and the results from generalized boundary conditions overestimated WSS in most of the cases. Meanwhile, the distribution of WSS was similar. The relationship between the generalized and specific simulation results can be approximated by the equation y = k × x, with a average adjusted R ² up to 0.96 ± 0.04. After normalization, k became near 1. Generalized boundary conditions could be used when the distribution was focused on.