Comparison of unsteady CFD blood flow simulation between PRM and UNST for subject-specific cerebrovascular trees. (A) Hemodynamic states along polylines (marked as dashed lines) passing from ICA and BA to downstream vessels of the arterial tree were plotted to compare predictions of blood pressure, velocity, wall shear stress and vorticity magnitude of parametric and unstructured meshes. Simulation results for WSS (B) and vorticity magnitude (C) of the UNST (black solid-line) and PRM meshes (blue solid-lines). The first, second and third rows correspond to the results at peak-systole, mid-diastole, and end-diastole of the cardiac cycle, respectively. Maximum WSS and vorticity magnitude differences were less than 5% and 3% over one cardiac cycle. PRM meshes required at least 10 times fewer elements to reach mesh-independent hemodynamic results.