4D Image-Based CFD Simulation of a Compliant Blood Vessel

SUMMARY Numerical simulation of fluid-structure interaction (FSI) in the arterial system is a challenging and time consuming procedure because of the intrinsic heterogeneous nature of the problem. Moreover, in patient-specific simulations, modeling of the vascular structure requires parameter identification still difficult to accomplish. On the other hand, new imaging devices provide time sequences of the moving vessel of interest. When one is interested only in the blood dynamics in the compliant vessel, a possible alternative to the full fluid-structure interaction simulation is to track the vessel displacement from the images and then to solve the fluid problem in the moving domain reconstructed accordingly. In this paper, we present an example of this image-based technique. We describe the steps necessary for this approach (image acquisition and 3D geometric reconstruction, motion tracking, computational fluid dynamics (CFD) simulation) and present some results referring to an aortic arch and a validation of the proposed technique vs. a traditional FSI simulation in a carotid bifurcation. This approach significantly reduces the CPU time since the dynamics of the structure is retrieved from the images instead of being numerically computed. This work places itself in the framework of a strong integration between data (images/measures) and simulations that is likely to introduce a significant improvement in the reliability of cardiovascular numerical mathematics.