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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

Maximum and mean values of hemodynamic factors for various inlet lengths under two different inlet boundary conditions: (A) velocity, (B) wall shear stress (WSS), (C) oscillatory shear index (OSI), and (D) percent errors defined as (value from Womersley flow-value from plug flow)/(value from plug flow)×100.
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Figure 6: Maximum and mean values of hemodynamic factors for various inlet lengths under two different inlet boundary conditions: (A) velocity, (B) wall shear stress (WSS), (C) oscillatory shear index (OSI), and (D) percent errors defined as (value from Womersley flow-value from plug flow)/(value from plug flow)×100.

Mentions: Several important hemodynamic factors should be noted along the inlet length (Fig. 6). All the values for hemodynamic factors decreased with increasing the inlet length regardless of the inlet BC; however, the values became almost the same when L>20D. When L=3D, the percent error of the maximum OSI value between two inlet BCs was the largest and its value was as high as 116.1%. However, when L>20D, all the errors caused by two inlet BCs were around zero, and the values for hemodynamic factors remained almost unchanged for different inlet lengths and BCs.


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

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

Maximum and mean values of hemodynamic factors for various inlet lengths under two different inlet boundary conditions: (A) velocity, (B) wall shear stress (WSS), (C) oscillatory shear index (OSI), and (D) percent errors defined as (value from Womersley flow-value from plug flow)/(value from plug flow)×100.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: Maximum and mean values of hemodynamic factors for various inlet lengths under two different inlet boundary conditions: (A) velocity, (B) wall shear stress (WSS), (C) oscillatory shear index (OSI), and (D) percent errors defined as (value from Womersley flow-value from plug flow)/(value from plug flow)×100.
Mentions: Several important hemodynamic factors should be noted along the inlet length (Fig. 6). All the values for hemodynamic factors decreased with increasing the inlet length regardless of the inlet BC; however, the values became almost the same when L>20D. When L=3D, the percent error of the maximum OSI value between two inlet BCs was the largest and its value was as high as 116.1%. However, when L>20D, all the errors caused by two inlet BCs were around zero, and the values for hemodynamic factors remained almost unchanged for different inlet lengths and BCs.

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