Multiscale modeling and simulation of brain blood flow

Abstract

The aim of this work is to present an overview of recent advances in multi-scale modeling of brain blood flow. In particular, we present some approaches that enable the study of multi-scale and multi-physics phenomena in the cerebral vasculature. We discuss the formulation of continuum and atomistic modeling approaches, present a consistent framework for their concurrent coupling, and list some of the challenges that one needs to overcome in achieving a seamless and scalable integration of heterogeneous numerical solvers. The effectiveness of the proposed framework is demonstrated in a realistic case involving modeling the thrombus formation process taking place on the wall of a patient-specific cerebral aneurysm. This highlights the ability of multi-scale algorithms to resolve important biophysical processes that span several spatial and temporal scales, potentially yielding new insight into the key aspects of brain blood flow in health and disease. Finally, we discuss open questions in multi-scale modeling and emerging topics of future research.

Quantification of near‐wall hemodynamic risk factors in large‐scale cerebral arterial trees

“…Future work should address the multi‐scale arterial to venous system simulation with consideration of vein wall compliance. Another possible future step is to integrate rigorous 3D CFD arterial tree simulations with lower order microcirculatory closures …”

“…Another possible future step is to integrate rigorous 3D CFD arterial tree simulations with lower order microcirculatory closures. 26,73,74 5 | CONCLUSION Global maps of hemodynamic risk parameters derived from in vivo measurements in combination with tree-wide CFD simulations provide unique global observations about the hemodynamic status that no current imaging technique is capable to visualize directly. Large-scale subject-specific hemodynamic analysis is a promising next step for quantifying the surgical outcomes.…”

“…Here, we propose the extension of excellent prior work to the large portion of the 3D cerebral arterial tree to enable near‐wall hemodynamic analysis. The ability of multi‐scale algorithms to resolve important biophysical processes of cerebral circulation has been addressed previously . However, previous global simulations were mostly performed on simplified flow network with 1D plug flow assumptions .…”

“…The ability of multi-scale algorithms to resolve important biophysical processes of cerebral circulation has been addressed previously. [24][25][26][27][28][29][30] However, previous global simulations were mostly performed on simplified flow network with 1D plug flow assumptions. [31][32][33][34] Our global approach has the advantage of assessing near-wall hemodynamic analysis for a large portion of the arterial tree with the inclusion of downstream vessels where undesired hemodynamics changes could occur far away from the site of intervention.…”

Scalable simulation of realistic volume fraction red blood cell flows through vascular networks

“…A different approach to simulating blood flow is with multiscale reduced-order models. By making simplifying assumptions about the fluid behavior throughout the domain and transforming the complex fluid system into a simpler flow problem, the macroscopic behaviors of enormous capillary systems can be characterized [33,34] and scaled up to thousands of cores [32]. This comes at a cost of local accuracy; by simulating the flows directly, we are able to accurately resolve local RBC dynamics that are not captured by such schemes.…”