Journal: Computers in biology and medicine

Article Title: Large-scale subject-specific cerebral arterial tree modeling using automated parametric mesh generation for blood flow simulation

doi: 10.1016/j.compbiomed.2017.10.028

Figure Lengend Snippet: Comparison of mesh quality and computational stability in 3D CFD blood flow simulations of cerebral arterial trees reconstructed with parametric (PRM) versus unstructured meshing (UNST). (A) Global view of CFL contours for a subject-specific cerebral arterial tree mesh with PRM and UNST. Magnified insert shows a small portion of the meshes. (B) For a given step size, all cells in the PRM meshes meets the CFL condition at much lower mesh density. For the same time step, more than 80% of the cells violate the CFL criterion (>1) in UNST. (C) Equiangular skew (abbr. as Skew). PRM meshing improves mean skewness by 20%. (D) Orthogonality (abbr. as Ortho); more than 97% of the PRM cells are almost perfectly orthogonal.

Article Snippet: To overcome this problem for large-scale modeling, we synthesized unstructured tetrahedral/prism meshes by using parametric surface meshes (PRM) and Delaunay method in ANSYS ICEMCFD (ANSYS Inc., Canonsburg, Pa., USA).

Techniques: Comparison

Journal: Computers in biology and medicine

Article Title: Large-scale subject-specific cerebral arterial tree modeling using automated parametric mesh generation for blood flow simulation

doi: 10.1016/j.compbiomed.2017.10.028

Figure Lengend Snippet: 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.

Article Snippet: To overcome this problem for large-scale modeling, we synthesized unstructured tetrahedral/prism meshes by using parametric surface meshes (PRM) and Delaunay method in ANSYS ICEMCFD (ANSYS Inc., Canonsburg, Pa., USA).

Techniques: Comparison, Shear

Journal: Computers in biology and medicine

Article Title: Large-scale subject-specific cerebral arterial tree modeling using automated parametric mesh generation for blood flow simulation

doi: 10.1016/j.compbiomed.2017.10.028

Figure Lengend Snippet: Preliminary 3D hemodynamic CFD analysis using parametric meshes in healthy and pathological cerebral arterial trees. (A) Predicted 3D pressure field for a large portion of cerebral arterial tree simulation at peak-systole in six volunteers. (B) Predicted wall shear stress distribution. (C–D) Hemodynamic simulation in patients with endovascular pathologies. Panel (C) illustrates the application of PRM method for a patient with MCA stenosis. Panel (D) summarizes results for a saccular aneurysm in the vertebral artery. It shows unstructured mesh for a saccular aneurysm in the right vertebral arteries fused to a parametric mesh of the vertebrobasilar system down to posterior cerebral arteries. The magnified insert depicts the hybrid mesh of unstructured aneurysm with parametric vascular tree meshes. The blood flow streamlines are shown for both stenosis and aneurysm pathological cases (right column of C and D panel).

Article Snippet: To overcome this problem for large-scale modeling, we synthesized unstructured tetrahedral/prism meshes by using parametric surface meshes (PRM) and Delaunay method in ANSYS ICEMCFD (ANSYS Inc., Canonsburg, Pa., USA).

Techniques: Shear