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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 outlet lengths from 0d to 4d when the inlet length is fixed to 26D. The plug flow and zero pressure condition are used as the inlet and outlet boundary conditions, respectively. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.
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Figure 7: Simulated hemodynamic factors at the systolic time for various outlet lengths from 0d to 4d when the inlet length is fixed to 26D. The plug flow and zero pressure condition are used as the inlet and outlet boundary conditions, respectively. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.

Mentions: Fig. 7 illustrates the contour of representative hemodynamic factors at the systolic time for various outlet lengths when the inlet length was fixed to L=26D and the plug flow and the zero pressure conditions were used as the inlet and outlet BCs, respectively. Several important hemodynamic factors were also calculated and presented along the outlet length (Fig. 8). Similar to the inlet length variation, the values for hemodynamic factors changed depending on the outlet length. As the outlet length was increased, all the values for hemodynamic factors increased up to K=2d and became constant thereafter.


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 outlet lengths from 0d to 4d when the inlet length is fixed to 26D. The plug flow and zero pressure condition are used as the inlet and outlet boundary conditions, respectively. 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 7: Simulated hemodynamic factors at the systolic time for various outlet lengths from 0d to 4d when the inlet length is fixed to 26D. The plug flow and zero pressure condition are used as the inlet and outlet boundary conditions, respectively. Arrows indicate the points where the values are considered most different from each contour. WSS, wall shear stress; OSI, oscillatory shear index.
Mentions: Fig. 7 illustrates the contour of representative hemodynamic factors at the systolic time for various outlet lengths when the inlet length was fixed to L=26D and the plug flow and the zero pressure conditions were used as the inlet and outlet BCs, respectively. Several important hemodynamic factors were also calculated and presented along the outlet length (Fig. 8). Similar to the inlet length variation, the values for hemodynamic factors changed depending on the outlet length. As the outlet length was increased, all the values for hemodynamic factors increased up to K=2d and became constant thereafter.

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