Computational Haemodynamics—An Introduction - Computational Hemodynamics: Theory, Modelling and Applications - page 6

1.3.3 Examination of Atherosclerosis

Medical image reconstruction of blood vessels has developed rapidly in recent de-
cades. In this section we review some work of atherosclerosis modeling. With the
development of modern imaging technology, especially magnetic resonance imag-
ing (MRI) and computed tomography (CT), arterial blood flow in subject-specific
physiologic models were quantified (Calcagno et al. 2013; Sanz and Fayad 2008;
Silvera et al. 2009). Computational methods to generate velocity and pressure fields
in idealized, generic models of the vascular anatomy and physiology was applied
by Taylor and Draney (2004). For three-dimensional numerical studies, CFD mod-
els of the carotid artery were constructed from MRI or CT images (Campbell et al.
2012) and the prediction for atheroma (Marshall et al. 2004a). The artery and its
wall shear stress was quantified using CFD flow equations (Farmakis et al. 2004).
Antiga et al. (2002) presented a methodology on bifurcation geometric reconstruc-
tion using CT angiography of carotid bifurcations from two patients affected by
severe atherosclerotic plaques.
CFD simulations based on MRI plays an important role in evaluating the rela-
tionship between local haemodynamics and the prediction for atheroma. This tech-
nique can be applied non-invasively at arterial sites where vascular anatomy typi-
cally exhibits substantial inter-individual variability. Simulations can demonstrate
local mechanical factors occurring in fluid-vessel interactions during the pathogen-
esis of atherosclerosis. For example, transient simulations that track the blood flow
through a complete cardiac cycle can be performed (Fig. 1.4 ). Results illustrate

Fig. 1.4 Models of stenosed carotid arteries and CFD simulated time-dependent wall shear stress.
Computational fluid dynamics can be used to analyse wall shear stress ( WSS ) distribution in ath-
erosclerotic arteries. The regions of high WSS appears at the stenosis, and can serve as a parameter
for grading the severity of atherosclerosis