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. 2020 Jan 17:10:1372.
doi: 10.3389/fneur.2019.01372. eCollection 2019.

Characteristics of Wall Shear Stress and Pressure of Intracranial Atherosclerosis Analyzed by a Computational Fluid Dynamics Model: A Pilot Study

Zimo Chen  1   2 , Haiqiang Qin  1   2   3   4 , Jia Liu  5 , Bokai Wu  5 , Zaiheng Cheng  5 , Yong Jiang  1   2   3   4 , Liping Liu  1   2   3   4 , Lina Jing  6 , Xinyi Leng  7 , Jing Jing  1   2   3   4 , Yilong Wang  1   2   3   4 , Yongjun Wang  1   2   3   4
Affiliations

Characteristics of Wall Shear Stress and Pressure of Intracranial Atherosclerosis Analyzed by a Computational Fluid Dynamics Model: A Pilot Study

Zimo Chen et al. Front Neurol. .

Abstract

Background: Although wall shear stress (WSS) and pressure play important roles in plaque vulnerability, characteristics of the two indices in intracranial atherosclerosis (ICAS) have not been fully investigated yet. This study aimed to elucidate this issue by means of establishing a non-invasive computational fluid dynamics method with time-of-flight magnetic resonance angiography (TOF-MRA) of the whole cerebral artery. Materials and Methods: Subjects with symptomatic ICAS in the middle cerebral artery domain were enrolled, excluding those with concomitant internal carotid artery stenosis. Based on patient-specific TOF-MRA images for three-dimensional (3D) meshes and arterial blood pressure with patient-specific carotid artery ultrasonography for inlet boundary conditions, patients' three-dimensional hemodynamics were modeled by a finite element method governed by Navier-Stokes equations. Results: Among the 55 atherosclerotic lesions analyzed by this TOF-MRA based computational fluid dynamics model, the maximum WSS (WSSmax) was most frequently detected at the apex points and the upper half of the upstream sections of the lesions, whereas the maximum pressure was most often located at the lower half of the upstream sections. As the percent stenosis increases, the relative value of WSSmax and pressure drop increased with significantly increasing steep beyond 50% stenosis. Moreover, WSSmax was found to linearly correlate with pressure drop in ICAS. Conclusions: This study on ICAS revealed certain trends of longitudinal distribution of WSS and pressure and the influences of percent stenosis on cerebral hemodynamics, as well as the correlations between WSS and pressure drop. It represents a step forward in applying computational flow simulation techniques in studying ICAS and stroke, in a patient-specific manner.

Keywords: cerebral hemodynamics; intracranial atherosclerosis; magnetic resonance angiography; mathematical modeling; pressure; wall shear stress.

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Figures

Figure 1
Figure 1
The results of a typical hemodynamic simulation. The five defined points of the prominent side are shown. Panels (A) and (B), respectively, show the results of WSS and pressure contour maps. Subfigures (a) and (b) show an area of 34.3% luminal stenosis in the right MCA M1 segment. We chose the posterior wall of the MCA as the prominent side of the lesion for measurement. The WSSmax was located at the upper half of upstream section, and the magnitude was 7.47 pa. The WSSmin was located at the downstream section, and the magnitude was 0.33 pa. The pressure ratio(termianl/origin) was 0.99. MCA, middle cerebral artery; WSS, wall shear stress; WSSmax, the maximum value of WSS; WSSmin, the minimum value of WSS; pressureterminal, the value of pressure at the terminal point; pressureorigin, the value of pressure at the origin point.
Figure 2
Figure 2
The scatterplots of correlations between indices of hemodynamic forces and percent stenosis. (A) Correlation between the WSS ratio(max/origin) and percent stenosis. (B) Correlation between the pressure ratio(terminal/origin) and percent stenosis. (C) Correlation between the WSS ratio(min/origin) and percent stenosis. WSS, wall shear stress; WSSmax, the maximum value of WSS; WSSmin, the minimum value of WSS; WSSorigin, the value of WSS at the origin point; pressureterminal, the value of pressure at the terminal point; pressureorigin, the value of pressure at the origin point.
Figure 3
Figure 3
The magnitude and distribution of WSS and pressure varying with different stenosis severity. Panels (A) and (B), respectively, show the results of WSS and pressure contour maps. Percent stenosis values of subfigures subfigures (a) and (b) were 47.1, 56.3, and 70.0%, respectively. WSS, wall shear stress.
Figure 4
Figure 4
The scatterplots of correlations between indices of hemodynamic forces. (A) Correlation between WSSmax and pressure ratio(terminal/origin). (B) Correlation between WSSmax and pressure drop(origin-to-terminal). WSS, wall shear stress; WSSmax, the maximum value of WSS; pressureterminal, the value of pressure at the terminal point; pressureorigin, the value of pressure at the origin point.
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References

    1. GBD 2016 Stroke Collaborators Global, regional, and national burden of stroke, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. (2019) 18:439–58. 10.1016/S1474-4422(19)30034-1 - DOI - PMC - PubMed
    1. Wang YJ, Zhao XQ, Liu LP, Soo YO, Pu Y, Pan Y, et al. . Prevalence and outcomes of symptomatic intracranial large artery stenoses and occlusions in China: the Chinese Intracranial Atherosclerosis (CICAS) Study. Stroke. (2014) 45:663–9. 10.1161/STROKEAHA.113.003508 - DOI - PubMed
    1. Chimowitz M, Lynn M, Howlett-Smith H, Stern BJ, Hertzberg VS, Frankel MR, et al. Warfarin-Aspirin Symptomatic intracranial disease trial investigators. Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis. N Engl J Med. (2005) 352:1305–16. 10.1056/NEJMoa043033 - DOI - PubMed
    1. Kasner SE, Chimowitz MI, Lynn MJ, Koo JS, Lee JH, Park JM, et al. . Predictors of ischemic stroke in the territory of a symptomatic intracranial arterial stenosis. Circulation. (2006) 113:555–63. 10.1161/CIRCULATIONAHA.105.578229 - DOI - PubMed
    1. Li ZY, Taviani V, Tang T, Sadat U, Young V, Patterson A, et al. . The mechanical triggers of plaque rupture: shear stress vs pressure gradient. Br J Radiol. (2009) 82:S39. 10.1259/bjr/15036781 - DOI - PubMed