Imperial College London

DrDeclanO'Regan

Faculty of MedicineInstitute of Clinical Sciences

Reader in Imaging Sciences
 
 
 
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Contact

 

+44 (0)20 3313 1510declan.oregan

 
 
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Location

 

Imaging Sciences DepartmentHammersmith HospitalHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Xu:2018:10.1063/1.5011960,
author = {Xu, XY and Pirola, S and Jarral, O and O'Regan, D and Asimakopoulos, G and Anderson, JR and Pepper, J and Athanasiou, T},
doi = {10.1063/1.5011960},
journal = {APL Bioengineering},
pages = {026101--1--026101--14},
title = {Computational study of aortic hemodynamics for patients with an abnormal aortic valve: the importance of secondary flow at the ascending aorta inlet},
url = {http://dx.doi.org/10.1063/1.5011960},
volume = {2},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Blood flow in the aorta is helical, but most computational studies ignore the presence of secondary flow components at the ascending aorta (AAo) inlet. The aim of this study is to ascertain the importance of inlet boundary conditions (BCs) in computational analysis of flow patterns in the thoracic aorta based on patient-specific images, with a particular focus on patients with an abnormal aortic valve. Two cases were studied: one presenting a severe aortic valve stenosis and the other with a mechanical valve. For both aorta models, three inlet BCs were compared; these included the flat profile and 1D through-plane velocity and 3D phase-contrast magnetic resonance imaging derived velocity profiles, with the latter being used for benchmarking. Our results showed that peak and mean velocities at the proximal end of the ascending aorta were underestimated by up to 41% when the secondary flow components were neglected. The results for helical flow descriptors highlighted the strong influence of secondary velocities on the helical flow structure in the AAo. Differences in all wall shear stress (WSS)-derived indices were much more pronounced in the AAo and aortic arch (AA) than in the descending aorta (DAo). Overall, this study demonstrates that using 3D velocity profiles as inlet BC is essential for patient-specific analysis of hemodynamics and WSS in the AAo and AA in the presence of an abnormal aortic valve. However, predicted flow in the DAo is less sensitive to the secondary velocities imposed at the inlet; hence, the 1D through-plane profile could be a sufficient inlet BC for studies focusing on distal regions of the thoracic aorta.
AU - Xu,XY
AU - Pirola,S
AU - Jarral,O
AU - O'Regan,D
AU - Asimakopoulos,G
AU - Anderson,JR
AU - Pepper,J
AU - Athanasiou,T
DO - 10.1063/1.5011960
EP - 1
PY - 2018///
SN - 2473-2877
SP - 026101
TI - Computational study of aortic hemodynamics for patients with an abnormal aortic valve: the importance of secondary flow at the ascending aorta inlet
T2 - APL Bioengineering
UR - http://dx.doi.org/10.1063/1.5011960
UR - http://hdl.handle.net/10044/1/57522
VL - 2
ER -