scholarly journals Multiscale Modeling of Endothelium Derived Wall Shear Stress Regulation in Common Carotid Artery

2019 ◽  
Vol 35 (6) ◽  
pp. 901-914
Author(s):  
Saeed Siri ◽  
Malikeh Nabaei ◽  
Nasser Fatouraee
Keyword(s):  
Mechanical Properties ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Common Carotid Artery ◽  
3D Model ◽  
Stable Condition ◽  
Patient Specific ◽  
Local Flow ◽  
Wall Shear

ABSTRACTShear induced autoregulation is the natural ability of organs to maintain the local hemodynamic stresses in a stable condition in spite of altering perfusion rate. Endothelium cells are shear sensitive mechanoreceptors that are responsible for regulating the arterial wall architecture and mechanical properties in order to maintain homeostasis. This occurs by means of vasoactive mediators, which cause vasodilation or vasoconstriction. In this paper we presented a multiscale model of local flow regulation. First, a lumped parameter model of the whole cardiovascular system was implemented. Then a 3D numerical model of human common carotid artery was constructed considering fluid-structure interaction. The CCA inflow waveform obtained from the extended 0D model was applied to the 3D model as the boundary condition. After applying the Head-Up Tilt test, the local hemodynamics were disturbed. By considering the wall shear stress as the regulation criterion, then altering the arterial mechanical properties and the following vasodilation, shear forces exerted on the inner lining of the vessel were regulated and returned to the normal range. The resulting 0D/3D model can be considered as a plat-form for a more complete model containing local and systemic cardiovascular control mechanisms and patient-specific geometries which can be used for clinical purposes.

Wall Shear Stress Measurement by Ultrafast Vector Flow Imaging for Atherosclerotic Carotid Stenosis

2019 ◽  
Author(s):  
Guillaume Goudot ◽  
Jonathan Poree ◽  
Olivier Pedreira ◽  
Lina Khider ◽  
Pierre Julia ◽  
...  
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Carotid Stenosis ◽  
Common Carotid Artery ◽  
Frame Rate ◽  
Carotid Artery Plaque ◽  
Local Flow ◽  
Linear Probe ◽  
Wall Shear

Objective Carotid plaque vulnerability assessment could guide the decision to perform endarterectomy. Ultrafast ultrasound imaging (UF) can evaluate local flow velocities over an entire 2D image, allowing measurement of the wall shear stress (WSS). We aimed at evaluating the feasibility of WSS measurement in a prospective series of patients with carotid stenosis. Methods UF acquisitions, performed with a linear probe, had an effective frame rate of 5000 Hz. The flow velocity was imaged over the entire plaque area. WSS was computed with the vector field speed using the formula: with the blood velocity and μ, the blood viscosity. The WSS measurement method was validated using a calibrated phantom. In vivo, WSS was analyzed in 5 areas of the carotid wall: common carotid artery, plaque ascent, plaque peak, plaque descent, internal carotid artery. Results Good correlation was found between in vitro measurement and the theoretical WSS values (R2 = 0.95; p < 0.001). 33 patients were prospectively evaluated, with a median carotid stenosis degree of 80 % [75–85]. The maximum WSS value over the cardiac cycle follows the shape of the plaque with an increase during the ascent, reaching its maximum value of 3.25 Pa [2.26–4.38] at the peak of the plaque, and a decrease after passing of the peak (0.93 Pa [0.80–1.19]) lower than the WSS values in the non-stenotic areas (1.47 Pa [1.12–1.77] for the common carotid artery). Conclusion UF allowed local and direct evaluation of the plaque’s WSS, thus better characterizing local hemodynamics to identify areas of vulnerability. Key Points: 

Basic study on estimation method of wall shear stress in common carotid artery using blood flow imaging

2020 ◽  
Vol 59 (SK) ◽  
pp. SKKE16 ◽  
Author(s):  
Ryo Nagaoka ◽  
Kazuma Ishikawa ◽  
Michiya Mozumi ◽  
Magnus Cinthio ◽  
Hideyuki Hasegawa
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Common Carotid Artery ◽  
Estimation Method ◽  
Flow Imaging ◽  
Basic Study ◽  
Blood Flow Imaging ◽  
Wall Shear

3041Wall shear stress measurement by ultrafast vector flow imaging for atherosclerotic carotid stenosis

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
G Goudot ◽  
L Khider ◽  
O Pedreira ◽  
J M Poree ◽  
P Julia ◽  
...  
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Internal Carotid Artery ◽  
Carotid Stenosis ◽  
Common Carotid Artery ◽  
Carotid Plaque ◽  
Internal Carotid ◽  
Plaque Vulnerability ◽  
Wall Shear

Abstract Background Carotid plaque vulnerability assessment is an important factor in guiding the decision to treat significant carotid stenosis. Ultrafast Ultrasound Imaging (UF) offers the possibility of evaluating local flow velocities over an entire 2D image, allowing access to velocity measurements in contact with the arterial wall and to measure the wall shear stress (WSS). Purpose To evaluate the feasibility of WSS measurement in a prospective series of patients with carotid stenosis. Methods A 7.5 MHz linear probe of an Aixplorer scanner was used. UF acquisitions had 3 tilted plane waves transmits (−10; 0; 10°) and an effective frame rate of 5000Hz. We evaluated the flow velocity in 5 areas of the carotid wall: common carotid artery (1), plaque ascent (2), plaque peak (3), plaque descent (4), internal carotid artery (5) (Figure). WSS was computed with the vector field speed using the following formula, WSS=μ·δn·v with v the blood velocity, n the normal vector to the vessel wall and μ, the blood viscosity, calculated from the hematocrit value for each patient. WSS measurement method was first validated using a laminar flow phantom and known viscosity. And then, 33 patients were then prospectively evaluated, with a median carotid stenosis degree of 80% [75–85]. Results Significant correlation was found between in vitro measurement and the theoretical WSS values (R2=0.95; p<0.001).In patients,the maximum WSS value over the cardiac cycle follows the shape of the plaque with an increase during the ascend, reaching its maximum value of 3.57 Pa [2.47–4.45] at the peak of the plaque, and a fall after passing the peak (0.99 Pa [0.8–1.32]) lower than the WSS values in the non-stenotic areas (1.55 Pa [1.13–1.90] for the common carotid artery) (Table). Table 1 Wall's area Wall shear stress (Pa) Min Max Delta 1. Common carotid artery 0.14 [0.05–0.27] 1.55 [1.13–1.90] 0.73 [0.55–0.96] 2. Plaque's ascent 0.39 [0.24–0.59] 2.63 [1.89–3.28] 1.20 [0.89–1.79] 3. Plaque's peak 0.60 [0.32–0.89] 3.57 [2.47–4.45] 1.78 [1.44–2.46] 4. Plaque's descent 0.16 [0.13–0.22] 0.99 [0.80–1.32] 0.52 [0.34–0.73] 5. Internal carotid artery 0.17 [0.13–0.35] 1.37 [1.04–1.75] 0.72 [0.50–0.87] Results are median [25th–75th percentile]. Figure 1 Conclusion UF provide reliable WSS values. High WSS was present at the peak of the plaque, whereas lowest WSS values were found at the post-stenotic zone. WSS evaluation may help to better characterize the carotid plaque vulnerability.

scholarly journals Optimized analysis of blood flow and wall shear stress in the common carotid artery of rat model by phase-contrast MRI

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shin-Lei Peng ◽  
Cheng-Ting Shih ◽  
Chiun-Wei Huang ◽  
Shao-Chieh Chiu ◽  
Wu-Chung Shen
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Rat Model ◽  
Common Carotid Artery ◽  
Phase Contrast ◽  
Phase Contrast Mri ◽  
The Common ◽  
Wall Shear

Analysis of Flow Disturbance in a Stenosed Carotid Artery Bifurcation Using Two-Equation Transitional and Turbulence Models

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
F. P. P. Tan ◽  
G. Soloperto ◽  
S. Bashford ◽  
N. B. Wood ◽  
S. Thom ◽  
...  
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
Laminar Flow ◽  
Wall Shear Stress ◽  
Turbulence Models ◽  
Carotid Bifurcation ◽  
Patient Specific ◽  
Shear Stresses ◽  
Zone Length ◽  
Wall Shear

In this study, newly developed two-equation turbulence models and transitional variants are employed for the prediction of blood flow patterns in a diseased carotid artery where the growth, progression, and structure of the plaque at rupture are closely linked to low and oscillating wall shear stresses. Moreover, the laminar-turbulent transition in the poststenotic zone can alter the separation zone length, wall shear stress, and pressure distribution over the plaque, with potential implications for stresses within the plaque. Following the validation with well established experimental measurements and numerical studies, a magnetic-resonance (MR) image-based model of the carotid bifurcation with 70% stenosis was reconstructed and simulated using realistic patient-specific conditions. Laminar flow, a correlation-based transitional version of Menter’s hybrid k‐ϵ∕k‐ω shear stress transport (SST) model and its “scale adaptive simulation” (SAS) variant were implemented in pulsatile simulations from which analyses of velocity profiles, wall shear stress, and turbulence intensity were conducted. In general, the transitional version of SST and its SAS variant are shown to give a better overall agreement than their standard counterparts with experimental data for pulsatile flow in an axisymmetric stenosed tube. For the patient-specific case reported, the wall shear stress analysis showed discernable differences between the laminar flow and SST transitional models but virtually no difference between the SST transitional model and its SAS variant.

NIDDM is associated with lower wall shear stress of the common carotid artery

Diabetes ◽  
1999 ◽  
Vol 48 (1) ◽  
pp. 193-197 ◽  
Author(s):  
C. Irace ◽  
C. Carallo ◽  
A. Crescenzo ◽  
C. Motti ◽  
M. S. De Franceschi ◽  
...  
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Common Carotid Artery ◽  
Lower Wall ◽  
The Common ◽  
Wall Shear

scholarly journals Assessment of turbulent blood flow and wall shear stress in aortic coarctation using image-based simulations

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Romana Perinajová ◽  
Joe F. Juffermans ◽  
Jonhatan Lorenzo Mercado ◽  
Jean-Paul Aben ◽  
Leon Ledoux ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Flows ◽  
Patient Specific ◽  
4D Flow Mri ◽  
4D Flow ◽  
Local Flow ◽  
Flow Mri ◽  
Wall Shear

AbstractIn this study, we analyzed turbulent flows through a phantom (a 180$$^{\circ }$$ ∘ bend with narrowing) at peak systole and a patient-specific coarctation of the aorta (CoA), with a pulsating flow, using magnetic resonance imaging (MRI) and computational fluid dynamics (CFD). For MRI, a 4D-flow MRI is performed using a 3T scanner. For CFD, the standard $$k-\epsilon $$ k - ϵ , shear stress transport $$k-\omega $$ k - ω , and Reynolds stress (RSM) models are applied. A good agreement between measured and simulated velocity is obtained for the phantom, especially for CFD with RSM. The wall shear stress (WSS) shows significant differences between CFD and MRI in absolute values, due to the limited near-wall resolution of MRI. However, normalized WSS shows qualitatively very similar distributions of the local values between MRI and CFD. Finally, a direct comparison between in vivo 4D-flow MRI and CFD with the RSM turbulence model is performed in the CoA. MRI can properly identify regions with locally elevated or suppressed WSS. If the exact values of the WSS are necessary, CFD is the preferred method. For future applications, we recommend the use of the combined MRI/CFD method for analysis and evaluation of the local flow patterns and WSS in the aorta.

Wall Shear Stress Assessment in the Common Carotid Artery of End-Stage Renal Failure Patients

Nephron ◽  
2002 ◽  
Vol 92 (3) ◽  
pp. 557-563 ◽  
Author(s):  
S.K. Samijo ◽  
R. Barkhuysen ◽  
J.M. Willigers ◽  
K.M.L. Leunissen ◽  
L.A.F. Ledoux ◽  
...  
Keyword(s):  
Renal Failure ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Common Carotid Artery ◽  
Stress Assessment ◽  
End Stage Renal Failure ◽  
The Common ◽  
Wall Shear ◽  
End Stage
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