Limits...
Influence of Parent Artery Segmentation and Boundary Conditions on Hemodynamic Characteristics of Intracranial Aneurysms.

Hua Y, Oh JH, Kim YB - Yonsei Med. J. (2015)

Bottom Line: Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases.Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs.The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Hanyang University, Seoul, Korea.

ABSTRACT

Purpose: The purpose of this study is to explore the influence of segmentation of the upstream and downstream parent artery and hemodynamic boundary conditions (BCs) on the evaluated hemodynamic factors for the computational fluid dynamics (CFD) analysis of intracranial aneurysms.

Materials and methods: Three dimensional patient-specific aneurysm models were analyzed by applying various combinations of inlet and outlet BCs. Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases.

Results: Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs. When the inlet length was relatively short, different inlet BCs showed different hemodynamic factors and the calculated hemodynamic factors were also dependent on the inlet length. However, when the inlet length (L) was long enough (L>20D, where D is the diameter of inlet section), the hemodynamic factors became similar regardless of the inlet BCs and lengths. The error due to different inlet BCs was negligible. The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length.

Conclusion: Simulated hemodynamic factors are highly sensitive to inlet BCs and upstream parent artery segmentation. The results of this work can provide an insight into how to build models and to apply BCs for more accurate estimation of hemodynamic factors from CFD simulations of intracranial aneurysms.

No MeSH data available.


Related in: MedlinePlus

Simulated hemodynamic factors at the systolic time for various inlet lengths from 3D to 30D when the outlet length is fixed to 3.5d. Both the Womersley and plug flows are applied as the inlet boundary conditions and the outlet boundary condition is set to the zero pressure condition. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4541663&req=5

Figure 5: Simulated hemodynamic factors at the systolic time for various inlet lengths from 3D to 30D when the outlet length is fixed to 3.5d. Both the Womersley and plug flows are applied as the inlet boundary conditions and the outlet boundary condition is set to the zero pressure condition. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.

Mentions: Fig. 5 compares the hemodynamic factors at the systolic time for different inlet BCs and inlet lengths (from 3D to 30D), when a fixed outlet length of K=3.5d was used and the outlet BC was set to zero pressure. The arrows indicate the points where the values of hemodynamic factors are considered most different from each contour. When the inlet length was small (L<16D), the hemodynamic factors were significantly different under the two different inlet BCs. For both the inlet BCs, the hemodynamic factors were also dependent on the inlet length. However, when the inlet length was large enough (L>20D), the contours for hemodynamic factors became quite similar regardless of which inlet BC was applied.


Influence of Parent Artery Segmentation and Boundary Conditions on Hemodynamic Characteristics of Intracranial Aneurysms.

Hua Y, Oh JH, Kim YB - Yonsei Med. J. (2015)

Simulated hemodynamic factors at the systolic time for various inlet lengths from 3D to 30D when the outlet length is fixed to 3.5d. Both the Womersley and plug flows are applied as the inlet boundary conditions and the outlet boundary condition is set to the zero pressure condition. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541663&req=5

Figure 5: Simulated hemodynamic factors at the systolic time for various inlet lengths from 3D to 30D when the outlet length is fixed to 3.5d. Both the Womersley and plug flows are applied as the inlet boundary conditions and the outlet boundary condition is set to the zero pressure condition. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.
Mentions: Fig. 5 compares the hemodynamic factors at the systolic time for different inlet BCs and inlet lengths (from 3D to 30D), when a fixed outlet length of K=3.5d was used and the outlet BC was set to zero pressure. The arrows indicate the points where the values of hemodynamic factors are considered most different from each contour. When the inlet length was small (L<16D), the hemodynamic factors were significantly different under the two different inlet BCs. For both the inlet BCs, the hemodynamic factors were also dependent on the inlet length. However, when the inlet length was large enough (L>20D), the contours for hemodynamic factors became quite similar regardless of which inlet BC was applied.

Bottom Line: Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases.Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs.The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Hanyang University, Seoul, Korea.

ABSTRACT

Purpose: The purpose of this study is to explore the influence of segmentation of the upstream and downstream parent artery and hemodynamic boundary conditions (BCs) on the evaluated hemodynamic factors for the computational fluid dynamics (CFD) analysis of intracranial aneurysms.

Materials and methods: Three dimensional patient-specific aneurysm models were analyzed by applying various combinations of inlet and outlet BCs. Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases.

Results: Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs. When the inlet length was relatively short, different inlet BCs showed different hemodynamic factors and the calculated hemodynamic factors were also dependent on the inlet length. However, when the inlet length (L) was long enough (L>20D, where D is the diameter of inlet section), the hemodynamic factors became similar regardless of the inlet BCs and lengths. The error due to different inlet BCs was negligible. The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length.

Conclusion: Simulated hemodynamic factors are highly sensitive to inlet BCs and upstream parent artery segmentation. The results of this work can provide an insight into how to build models and to apply BCs for more accurate estimation of hemodynamic factors from CFD simulations of intracranial aneurysms.

No MeSH data available.


Related in: MedlinePlus