Measurement of wall shear stress in chick embryonic heart using optical coherence tomography

2015 ◽  
Author(s):  
Zhenhe Ma ◽  
Shidan Dou ◽  
Yuqian Zhao ◽  
Yi Wang ◽  
Yanyan Suo ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Embryonic Heart ◽  
Optical Coherence ◽  
Wall Shear

Intimal Thickening Sourced From Low Wall Shear Stress in Human Left Coronary Artery Was Observed by Optical Coherence Tomography

2011 ◽  
Author(s):  
Jin Suo ◽  
Michael McDaniel ◽  
Parham Eshtehardi ◽  
Saurabh S. Dhawan ◽  
Lucas H. Timmins ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
Coronary Artery ◽  
Wall Shear Stress ◽  
Optical Coherence ◽  
Intimal Thickening ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Wall Shear ◽  
Artery Disease

The high resolution of optical coherence tomography (OCT) may offer improved description of luminal surfaces and intimal thickening in human coronary arteries by comparison to other imaging modalities, such as intravascular ultrasound (IVUS). We investigated the left anterior descending (LAD) coronary artery of a patient using both OCT and IVUS methods and found an asymmetrical distribution of intimal thickness (IT) around the lumen circumference in the OCT images, whereas the IVUS images showed a lumen with no asymmetry in IT. We reconstructed a 3D coronary artery model from the OCT slices that represented the morphological details of local luminal surfaces accurately and used this to simulate the pulsatile flow field in the model employing computational fluid dynamics (CFD). The pulsatile wall shear stress (WSS) distribution on the LAD surface was derived, and time-averaged WSS was computed. The data for IT and WSS distributions in the LAD segment were compared, and a linear inverse relationship between IT and WSS was found; higher WSS (> 25±5 dynes per square centimeter) favors thinner intima (< 0.12±0.05 millimeters) and lower WSS (< 12±5 dynes per square centimeter) favors thicker intima (> 0.33±0.05 millimeters). The enhanced spatial resolution of OCT offers an improved imaging technique for developing CFD models and assessing early atherosclerosis in patients with coronary artery disease.

scholarly journals Moving shear stress towards the clinic: preclinical comparison of optical coherence tomography-based versus angiography-based time-averaged wall shear stress estimations

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J Naser ◽  
N Fogell ◽  
M Patel ◽  
P Yang ◽  
R Krams ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Coronary Arteries ◽  
Gold Standard ◽  
Optical Coherence ◽  
Cfd Simulations ◽  
Intracoronary Imaging ◽  
Wall Shear ◽  
Stenotic Arteries

Abstract Introduction Identification of coronary atherosclerotic plaques at risk of causing future acute coronary syndromes remains a major unmet clinical challenge. The addition of vessel biomechanics to intracoronary imaging derived evaluation of plaque morphology, improves identification of plaques likely to develop high risk features. We and others have developed a framework for intracoronary imaging (optical coherence tomography [OCT]) based 3D reconstructions of coronary arteries for computational fluid dynamics (CFD) simulations of shear stress, which are considered the current gold standard approach for quantification of coronary arterial haemodynamics. However, these approaches are time consuming and computationally intensive, resulting in a barrier to clinical uptake. Purpose Determination of time averaged wall shear stress (TAWSS) based on 3D coronary geometries from non-invasive 3D Quantitative Coronary Angiography (3D-QCA) has recently been developed (Pie Medical Imaging, Netherlands), which enables results of shear stress simulations to be available within 30 minutes. We sought to compare TAWSS determined from 3D-QCA with gold standard OCT-based CFD simulations in both normal and stenotic arteries in minipigs. Methods 15 normal and 5 stenotic minipig coronary arteries were studied. Anatomically matched 3D arterial geometries were reconstructed from 3D-QCA and OCT using common centrelines. Boundary conditions for simulations included directly measured inlet blood velocities; parabolic inlet flow profiles, zero pressure outlet; no-slip arterial walls; blood density: 1.05 g/ml; blood dynamic viscosity: 0.035 g/cm.s. Blood was modelled as Newtonian. 3D-QCA TAWSS was obtained with a Kratos Multi-Physics CFD solver. OCT-based simulations were performed using Abaqus/CFD v6.14. TAWSS was calculated for 80 axially matched segments for both methods (1200 and 400 paired comparisons for normal and stenotic arteries, respectively). Data were analysed using Bland-Altman and Wilcoxon matched-pairs signed ranked tests. Results Computation times for 3D-QCA and OCT-based CFD were approximately 30 minutes and 2 hours respectively. Axial profiles of TAWSS were similar between the two methods and there was agreement in TAWSS magnitudes and narrow 95% limits of agreement (Figure 1 and Figure 2). Using co-registered TAWSS maps generated by each method, we find similar spatial regional distributions of TAWSS in both normal and stenotic arteries. Conclusions Our data suggest that 3D-QCA based TAWSS is feasible in both normal and stenotic arteries. Spatial TAWSS distributions between the two methods are similar with agreement in matched TAWSS comparisons, though there are some small systematic differences in the absolute values of TAWSS, due to different resultant arterial geometries. These encouraging data suggest that further clinical evaluation of rapid TAWSS from 3D-QCA is warranted, which may facilitate clinical adoption of TAWSS assessment. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Medical Research Council

scholarly journals Potential relationship between high wall shear stress and plaque rupture that cause acute coronary syndrome: insights from optical coherence tomography based computational fluid dynamic simulation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Fukuyama ◽  
H Otake ◽  
F Seike ◽  
H Kawamori ◽  
T Toba ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
Acute Coronary Syndrome ◽  
Wall Shear Stress ◽  
Plaque Rupture ◽  
Optical Coherence ◽  
Lumen Area ◽  
Segmental Analysis ◽  
Coronary Syndrome ◽  
Fibrous Cap

Abstract Background The direct relationship between plaque rupture (PR) that cause acute coronary syndrome (ACS) and wall shear stress (WSS) remains uncertain. Methods From the Kobe University ACS-OCT registry, one hundred ACS patients whose culprit lesions had PR documented by optical coherence tomography (OCT) were enrolled. Lesion-specific 3D coronary artery models were created using OCT data. Specifically, at the ruptured portion, the tracing of the luminal edge of the residual fibrous cap was smoothly extrapolated to reconstruct the luminal contour before PR. Then, WSS was computed from computational fluid dynamics (CFD) analysis by a single core laboratory. Relationships between WSS and the location of PR were assessed with 1) longitudinal 3-mm segmental analysis and 2) circumferential analysis. In the longitudinal segmental analysis, each culprit lesion was subdivided into five 3-mm segments with respect to the minimum lumen area (MLA) location at the centered segment (Figure. 1). In the circumferential analysis, we measured WSS values at five points from PR site and non-PR site on the cross-sections with PR. Also, each ruptured plaque was categorized into the lateral type PR (L-PR), central type PR (C-PR), and others according to the relation between the site of tearing and the cavity (Figure. 2). Results In the longitudinal 3-mm segmental analysis, the incidences of PR at upstream (UP1 and 2), MLA, and downstream (DN1 and 2) were 45%, 40%, and 15%, respectively. The highest average WSS was located in UP1 in the upstream PR (UP1: 15.5 (10.4–26.3) vs. others: 6.8 (3.3–14.7) Pa, p&lt;0.001) and MLA segment in the MLA PR (MLA: 18.8 (6.0–34.3) vs. others: 6.5 (3.1–11.8) Pa, p&lt;0.001), and the second highest WSS was located at DN1 in the downstream PR (DN1: 5.8 (3.7–11.5) vs. others: 5.5 (3.7–16.5) Pa, p=0.035). In the circumferential analysis, the average WSS at PR site was significantly higher than that of non-PR site (18.7 (7.2–35.1) vs. 13.9 (5.2–30.3) Pa, p&lt;0.001). The incidence of L-PR, C-PR, and others were 51%, 42%, and 7%, respectively. In the L-PR, the peak WSS was most frequently observed in the lateral site (66.7%), whereas that in the C-PR was most frequently observed in the center site (70%) (Figure. 3). In the L-PR, the peak WSS value was significantly lower (44.6 (19.6–65.2) vs. 84.7 (36.6–177.5) Pa, p&lt;0.001), and the thickness of broken fibrous cap was significantly thinner (40 (30–50) vs. 80 (67.5–100) μm, p&lt;0.001), and the lumen area at peak WSS site was significantly larger than those of C-PR (1.5 (1.3–2.0) vs. 1.4 (1.1–1.6) mm2, p=0.008). Multivariate analysis demonstrated that the presence of peak WSS at lateral site, thinner broken fibrous cap thickness, and larger lumen area at peak WSS site were independently associated with the development of the L-PR. Conclusions A combined approach with CFD simulation and morphological plaque evaluation by using OCT might be helpful to predict future ACS events induced by PR. Funding Acknowledgement Type of funding source: None

Correction: Development of a Two-Dimensional Wall Shear Stress Sensor for Wind Tunnel Applications

2019 ◽  
Author(s):  
Brett Freidkes ◽  
David A. Mills ◽  
Casey Keane ◽  
Lawrence S. Ukeiley ◽  
Mark Sheplak
Keyword(s):  
Shear Stress ◽  
Wind Tunnel ◽  
Wall Shear Stress ◽  
Two Dimensional ◽  
Stress Sensor ◽  
Shear Stress Sensor ◽  
Wall Shear
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