Accurate noninvasive quantitation of blood flow, cross-sectional lumen vessel area and wall shear stress by three-dimensional paraboloid modeling of magnetic resonance imaging velocity data

Abstract

We describe a new noninvasive method for highly accurate estimation of blood flow, cross-sectional lumen vessel area and wall shear stress. In vitro results and statistical analysis demonstrate the feasibility of the method, and the first in vivo results are comparable to published data.

Computational Modelling of Pulsating Biological Flow

“…The mean shear stress variation and blood flux variation with time. The characteristics of the computed the shear stress variation is consistent with the experimental results by Oyre et al [6]. It is worth pointing out that there exists a peak for shear stress for a given pulsating pressure gradient, and thus the peak shear stress could directly affect the rupture of the stenotic plagues.…”

“…Most earlier studies [1,2,6] assume the following form ∂p ∂z = A cos(ωt) + γ, ∂p ∂r = 0, where γ is the background pressure gradient. In fact, we can assume any known function form for the pressure gradient in terms of a Fourier expansion.…”

“…The common clinical observations suggest that the atheromatous disease arise mainly at the bifurcation of arteries. The benefit of modelling this phenomena is obviously profound both in clinical treatment and biomedical research [1,2,5,6]. However, most models describing these phenomena only produce some basic features which are far from reality.…”

Modeling and simulation of flow in cerebral aneurysms

“…The mean value averaged over 10 pulses at Re = 250 is found to be around 1.4 Pa with peak values near 2.6 Pa. At higher (possibly pathological) Reynolds number Re = 400 we observe a change in mean value up to 2.5 Pa and a considerable increase in peak values to 6.2 Pa averaged over 10 pulses. These values show the same general magnitude as reported in [29,70]. Transitional dynamics is clearly observed in Figure 4.5(b).…”

“…We consider a full range of physiologically relevant conditions and show that the flow undergoes a transition from an orderly state at low Reynolds numbers (Re = 100, 200), in which the pulsatile forcing is closely followed in time, to a complex response with strongly increased high-frequency components at higher Reynolds numbers (Re = 400), i.e., at higher flow rates and larger aneurysm sizes. The results obtained for the shear stress correspond to values found in literature [29,70], thereby providing an additional validation of the computational model. The numerical reliability of the predicted transition is quantified on the basis of the bounding solutions approach.…”