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Outline. . Methods (anatomical structure, mathematical models, input variables) Clinical applications Other related issues (reproducibility, validation) Limitations and future work. Methods. Anatomical structureImage acquisition: CT, MRI and 3D ultrasound. E.g. carotid arteries scanned using MRI 2D TOF sequence, 5-inch coil, 1.5mm slice thickness, in-plane resolution about 0.5 mm, contrast enhanced, ~100mm scan length.Geometry reconstruction: 2D, 3D segmentation, manual, semi9450
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1. Image-based modelling of blood flow in the human cardiovascular system
3. Methods Anatomical structure
Image acquisition: CT, MRI and 3D ultrasound. E.g. carotid arteries scanned using MRI 2D TOF sequence, 5-inch coil, 1.5mm slice thickness, in-plane resolution about 0.5 mm, contrast enhanced, ~100mm scan length.
Geometry reconstruction: 2D, 3D segmentation, manual, semi-automatic or automatic; 3D surface reconstruction and smoothing
4. 3D Imaging
5. Freehand 3DUS acquisition system
6. Stored Slices
7. Contour definition
8. Surface reconstruction
9. Vessel visualization
11. Flow/wall coupling scheme
12. Input variables Flow at boundaries: pulsed Doppler or PC MRI.
Pressure at boundaries: high-fidelity external pressure transducer (model SPT-301, Millar Instruments)
Wall thickness and elastic property: IMT using B-mode ultrasound (or MRI), wall tracking using M-mode ultrasound.
13. Examples of clinical applications
14. Carotid bifurcation
15. Wall thickness and elastic property
16. Boundary conditions Inlet (CCA): time-varying Womersley velocity profiles derived from measured centreline velocity using pulsed Doppler
Outlet (ICA): time-varying mass flow rate determined from ultrasound measurement
Outlet (ECA): time-varying pressure determined by tonometry measurement
No longitudinal motion and rotation of the bifurcation
Zero pre-axial strain, incremental P loading from diastolic to systolic phase
17. Particle tracking
18. WSS and mechanical stress(time-averaged)
19. WSS and mechanical stress
20. The aortic bifurcation
21. Aortic bifurcation
22. Time-averaged WSS
23. Femoral arteries
24. Femoral arteries
25. Other related issues
26. Other related issues
27. Limitations
Effect of pre-axial strain
Effect of different mechanical properties for CCA, ICA and ECA
Effect of hyperelasticity?
Effect of non-Newtonian viscosity
More validations, sensitivity and reproducibility studies necessary
28. Other on-going projects and future work Femoral bypass graft
Analysis of patient-specific intraventricular flow patterns using MRI/CFD
Reparied coarctation of the aorta in children
Flow and wall behaviour in arteries with plaques
MRI vs 3DUS
29. Acknowledgement Funding
British Heart Foundation
EPSRC
ASTRA Researchers Collaborators
Dr Q.Long Prof A.Hughes Dr M.Jackson Dr S.Thom
Dr B.Ariff Prof T.M.Griffith
Dr S.Zhao Dr I.Marshall
Dr A.Zambanini Dr P.Hoskin
Kawai Lee
Alex Augst
Pooi-Ling Cheong
Dean Barratt