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Motoya Hayase - One of the best experts on this subject based on the ideXlab platform.
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in vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion flushing catheter a comparison with intravascular ultrasound
Ultrasound in Medicine and Biology, 2005Co-Authors: Yoshiaki Kawase, Kozo Hoshino, Ryuichi Yoneyama, Jennifer Mcgregor, Roger J Hajjar, Ikkyung Jang, Motoya HayaseAbstract:Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized Pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized Pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized Pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries. (E-mail: ykawase@partners.org)
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In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: A comparison with intravascular ultrasound
Ultrasound in medicine & biology, 2005Co-Authors: Yoshiaki Kawase, Kozo Hoshino, Ryuichi Yoneyama, Jennifer Mcgregor, Roger J Hajjar, Ikkyung Jang, Motoya HayaseAbstract:Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized Pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized Pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized Pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries.
Yoshiaki Kawase - One of the best experts on this subject based on the ideXlab platform.
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difference in functional assessment of individual stenosis severity in serial coronary lesions between resting and hyperemic pressure wire Pullback insights from the gift registry
International Journal of Cardiology, 2020Co-Authors: Yoshiaki Kawase, Takayuki Warisawa, James P Howard, Toru Tanigaki, Hiroyuki Omori, Christopher Cook, Yousif Ahmad, Darrel P Francis, Yoshihiro J AkashiAbstract:Abstract Background Identifying the individual hemodynamic significance of tandem coronary artery lesions can be complicated by the crosstalk phenomenon which occurs between serial stenoses under hyperemic conditions. Physiological assessments performed under resting conditions are considered to be, theoretically, less affected by the hemodynamic interaction between serial coronary stenoses. The purpose of this study was to assess whether pressure-wire (PW) Pullback measurements at rest and during hyperemia provided different information as to which stenosis appeared to be most functionally significant. Methods In consecutive patients with angiographically discrete serial lesions, physiological lesion predominance (i.e. proximal or distal) was defined according to the pressure gradient along the vessels on PW-Pullback trace. We used instantaneous wave-free ratio (iFR) based assessment as the reference standard and compared fractional flow reserve (FFR) based and hyperemic-iFR based lesion predominance. Results Eighty-eight vessels (70 patients, mean age 70.3 ± 9.4 years, 80% male) were included in this study. Median iFR, FFR and hyperemic-iFR were 0.85 (interquartile range [IQR]: 0.74 to 0.91), 0.73 (IQR: 0.65 to 0.80) and 0.60 (IQR: 0.49 to 0.71), respectively. When judged against iFR-Pullback based physiological assessment, lesion predominance changed in 22.7% (20/88) in FFR and in 20.5% (18/88) in hyperemic-iFR, respectively. There was no statistical difference between FFR and hyperemic-iFR for the impact on these changes (p = 0.77). Conclusions In serial coronary lesions, hyperemic PW-Pullback disagreed with resting PW-Pullback on the lesion-specific identification of ischemia in approximately 20% of cases, either in whole cardiac cycle or in wave-free period.
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in vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion flushing catheter a comparison with intravascular ultrasound
Ultrasound in Medicine and Biology, 2005Co-Authors: Yoshiaki Kawase, Kozo Hoshino, Ryuichi Yoneyama, Jennifer Mcgregor, Roger J Hajjar, Ikkyung Jang, Motoya HayaseAbstract:Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized Pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized Pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized Pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries. (E-mail: ykawase@partners.org)
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In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: A comparison with intravascular ultrasound
Ultrasound in medicine & biology, 2005Co-Authors: Yoshiaki Kawase, Kozo Hoshino, Ryuichi Yoneyama, Jennifer Mcgregor, Roger J Hajjar, Ikkyung Jang, Motoya HayaseAbstract:Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized Pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized Pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized Pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries.
Xinguang Yang - One of the best experts on this subject based on the ideXlab platform.
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dynamics of a 3d brinkman forchheimer equation with infinite delay
Communications on Pure and Applied Analysis, 2021Co-Authors: Wenjing Liu, Rong Yang, Xinguang YangAbstract:This paper is concerned with the Pullback dynamics and asymptotic stability for a 3D Brinkman-Forchheimer equation with infinite delay. The well-posedness of weak solution to the 3D Brinkman-Forchheimer flow with infinite delay is investigated in the weighted space \begin{document}$ C_\kappa(H) $\end{document} firstly, then the Pullback attractors are presented for the process of weak solution. Moreover, the existence of global attractor and the exponential stability analysis of stationary solutions are shown, which is based on the estimate of corresponding steady state equation.
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the structure and stability of Pullback attractors for 3d brinkman forchheimer equation with delay
Electronic Research Archive, 2020Co-Authors: Xinguang Yang, Xingjie Yan, Ling DingAbstract:This paper concerns the stability of Pullback attractors for 3D Brinkman-Forchheimer equation with delays. By some regular estimates and the variable index to deal with the delay term, we get the sufficient conditions for asymptotic stability of trajectories inside the Pullback attractors for a fluid flow model in porous medium by generalized Grashof numbers.
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Pullback dynamics of 3d navier stokes equations with nonlinear viscosity
Nonlinear Analysis-real World Applications, 2019Co-Authors: Xinguang Yang, Baowei Feng, Shubin WangAbstract:Abstract This paper is concerned with Pullback dynamics of 3D Navier–Stokes equations with variable viscosity and subject to time-dependent external forces. Our main result establishes the existence of finite-dimensional Pullback attractors in a general setting involving tempered universes. We also present a sufficient condition on the viscosity coefficients that guarantees the attractors are nontrivial. We end the paper by showing the upper semi-continuity of Pullback attractors as the non-autonomous perturbation vanishes.
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Pullback dynamics of 2d incompressible non autonomous navier stokes equation on lipschitz like domain
arXiv: Analysis of PDEs, 2018Co-Authors: Xinguang Yang, Yuming QinAbstract:This paper concerns the tempered Pullback dynamics of 2D incompressible non-autonomous Navier-Stokes equation with non-homogeneous boundary condition on Lipschitz-like domain. With the presence of a time-dependent external force f(t) which only needs to be Pullback translation bounded, we establish the existence of a minimal Pullback attractor with respect to a universe of tempered sets for the corresponding non-autonomous dynamical system. We then give estimate on the finite fractal dimension of the attractor based on trace formula. Under the additional assumption that the external force is the sum of a stationary force and a non-autonomous perturbation, we also prove the upper semi-continuity of the attractors as the non-autonomous perturbation vanishes. Lastly, we also investigate the regularity of these attractors when smoother initial data is given. Our results are new even in the case of smooth domains.
Patrick W Serruys - One of the best experts on this subject based on the ideXlab platform.
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high speed intracoronary optical frequency domain imaging implications for three dimensional reconstruction and quantitative analysis
Eurointervention, 2012Co-Authors: Takayuki Okamura, Yoshinobu Onuma, Hector M Garciagarcia, Nico Bruining, Patrick W SerruysAbstract:textabstractAim: To assess the reproducibility of quantitative analysis of optical frequency domain imaging (OFDI) acquired at different Pullback speeds (20, 30, 40 mm/sec), as well as the impact of cardiac motion artefact on three-dimensional (3D) reconstructions. Methods and results: A total of 36 OFDI Pullbacks were obtained pre- and post-stent implantation at the Pullback speeds of 20, 30 and 40 mm/sec in non-diseased swine coronary arteries. The amount of x-ray contrast needed for blood clearance during OFDI imaging was recorded. Three-dimensional images of stented segments were rendered and artefacts on 3D images were assessed. Lumen areas (LA) were measured on each individual frame in pre- and post-stent Pullbacks. The volume of contrast used with a Pullback speed of 40 mm/sec was significantly smaller than with those of 30 and 20 mm/sec (10.8±1.8, 12.9±1.6, 15.9±2.6 ml, p<0.01, respectively). Three-dimensional reconstruction was feasible in all Pullbacks. Faster Pullback speeds resulted in a smaller number of artefacts. For quantitative measurement, a total of 7,426 frames were analysed. In non-stented vessels, LA derived from corresponding selected frames increased significantly with increasing Pullback speeds (6.35±2.14 vs. 6.58±2.10 mm 2 for 20 vs. 30 mm/sec [p<0.001], 6.36±2.13 vs. 6.75±2.09 mm 2 for 20 vs. 40 mm/sec [p<0.001]), whereas in stented vessels there was no significant difference in mean LA between the three different Pullback speeds (6.75±1.30 vs. 6.78±1.36 mm 2 for 20 vs. 30 mm/sec [NS], 6.74±1.30 vs. 6.76±1.31 mm 2 for 20 vs. 40 mm/sec [NS]). Conclusions: Quantitative analysis of OFDI obtained at different Pullback speeds in non-stented coronary arteries could potentially vary in LA measurement. OFDI with high-speed Pullback allows quantitative analysis of stented vessels while reducing the amount of contrast and cardiac motion artefacts.
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reproducibility of coronary fourier domain optical coherence tomography quantitative analysis of in vivo stented coronary arteries using three different software packages
Eurointervention, 2010Co-Authors: Takayuki Okamura, Juan Luis Gutierrezchico, Nico Bruining, Patrick W Serruys, Robertjan Van Geuns, Nieves Gonzalo, Sebastiaan De Winter, Jouke Dijkstra, Koen H Commossaris, Gijs Van SoestAbstract:textabstractAims: Fourier domain optical coherence tomography (FD OCT) enables imaging of long coronary artery segments within few seconds, employing high data acquisitions, speed and fast automated catheter Pullback. However, the reproducibility of these high-speed Pullbacks in the clinical situation is unknown. We tested the reproducibility of in vivo, intracoronary FD OCT and assessed the influence of different computer-assisted algorithms on quantitative analysis. Methods and results: In patients undergoing elective coronary stenting, two repeated FD OCT Pullbacks (20 mm/sec), were acquired. Lumen area (LA) and stent area (SA) were measured at 1 mm longitudinal intervals (n=18 Pullbacks, n=326 frames). Inter-study variability in terms of absolute difference of mean LA, mean SA and minimum LA was very low (-0.06±0.28 mm2, -0.05±0.29 mm2 and -0.11±0.33 mm 2 in software 1) Sources of variability were incomplete visualisation of the vessel circumference, ambiguous luminal borders and drift of internal catheter calibration (Z-offset). Inter-software variability for LA and SA was low (R2=0.98 - 1.00, p<0.01, respectively). Conclusions: FD OCT shows excellent reproducibility for consecutive Pullbacks and represents a reliable tool for the in vivo assessment of stented coronaries. Computer-assisted quantitative analysis of FD OCT may be a valuable tool for future studies.
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a novel approach for quantitative analysis of intracoronary optical coherence tomography high inter observer agreement with computer assisted contour detection
Catheterization and Cardiovascular Interventions, 2008Co-Authors: Shuzou Tanimoto, Nico Bruining, Patrick W Serruys, Sebastiaan De Winter, Gaston A Rodriguezgranillo, Peter Barlis, Ronald Hamers, Michiel Knappen, Stefan Verheye, Evelyn RegarAbstract:OBJECTIVE This study aims to examine observer-related variability of quantitative optical coherence tomography (OCT) derived measurements from both in vitro and in vivo Pullback data. BACKGROUND Intravascular OCT is a new imaging modality using infrared light and offering 10 times higher image resolution (15 microm) compared to intravascular ultrasound. The quantitative analysis of in vivo intracoronary OCT imaging is complicated by the presence of blood, motion artifacts and the large quantity of information that has to be processed. METHODS We developed a standardized, automated quantification process for intracoronary OCT Pullback data with inter-observer variability assessed both in vitro by using postmortem human coronary arteries and in vivo by studying simple and complex coronary pathology and outcomes following stent implantation. The consensus between measurements by two observers was analyzed using the intraclass and interclass correlation coefficient and the reliability coefficients. Bland-Altman plots were generated to assess the relationship between variability and absolute measurements. RESULTS In vitro OCT assessment was performed in nine postmortem coronary arteries. The time needed for semiautomated contour detection of a 15-mm long coronary segment was approximately 40 min. The absolute and relative difference between lumen area measurements derived from two observers was low [0.02 +/- 0.10 mm(2); (0.3 +/- 0.5)% respectively] with excellent correlation confirmed by linear regression analysis (R(2) = 0.99; P < 0.001). Similarly, in vivo measurements demonstrated a high correlation with the main source of inter-observer variation occurring as a result of coronary dissection and motion artifact. The absolute and relative difference between measurements were 0.11 +/- 0.33 mm(2) (1.57 +/- 0.05)% for lumen area (R(2) = 0.98; P < 0.001), 0.17 +/- 0.68 mm(2) (1.44 +/- 0.08)% for stent area (R(2) = 0.94; P < 0.001), and 0.26 +/- 0.72 mm(2) (14.08 +/- 0.37)% for neointimal area (R(2) = 0.78; P < 0.001). CONCLUSIONS Highly accurate computer-assisted quantitative analysis ofintracoronary OCT Pullbacks is feasible with low inter-observer variability. The presented approach allows for observer independent analysis of detailed vessel structures, and may be a valuable tool for future longitudinal studies incorporating OCT.
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true 3 dimensional reconstruction of coronary arteries in patients by fusion of angiography and ivus angus and its quantitative validation
Circulation, 2000Co-Authors: Cornelis J Slager, Patrick W Serruys, Jolanda J Wentzel, Johan C H Schuurbiers, Jan A Oomen, Jeroen Kloet, Rob Krams, Clemens Von Birgelen, Willem J Van Der Giessen, Pim J De FeyterAbstract:Background—True 3D reconstruction of coronary arteries in patients based on intravascular ultrasound (IVUS) may be achieved by fusing angiographic and IVUS information (ANGUS). The clinical applicability of ANGUS was tested, and its accuracy was evaluated quantitatively. Methods and Results—In 16 patients who were investigated 6 months after stent implantation, a sheath-based catheter was used to acquire IVUS images during an R-wave–triggered, motorized stepped Pullback. First, a single set of end-diastolic biplane angiographic images documented the 3D location of the catheter at the beginning of Pullback. From this set, the 3D Pullback trajectory was predicted. Second, contours of the lumen or stent obtained from IVUS were fused with the 3D trajectory. Third, the angular rotation of the reconstruction was optimized by quantitative matching of the silhouettes of the 3D reconstruction with the actual biplane images. Reconstructions were obtained in 12 patients. The number of Pullback steps, which determine...
Bixiang Wang - One of the best experts on this subject based on the ideXlab platform.
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weak Pullback attractors for mean random dynamical systems in bochner spaces
Journal of Dynamics and Differential Equations, 2019Co-Authors: Bixiang WangAbstract:This paper is concerned with weak Pullback mean random attractors for mean random dynamical systems defined in Bochner spaces. We first introduce the concept of weak Pullback mean random attractor with respect to the weak topology of reflexive Bochner spaces and then provide a sufficient criterion for existence and uniqueness of such attractors over a complete filtered probability space. As an application, we prove the existence and uniqueness of weak Pullback mean random attractors for the stochastic reaction–diffusion equations with nonlinear drift terms as well as nonlinear diffusion terms. We also establish the existence and uniqueness of such attractors for the deterministic reaction–diffusion equations with random initial data. In this case, the periodicity of the weak Pullback mean random attractors is also proved whenever the external forcing terms are periodic in time.
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sufficient and necessary criteria for existence of Pullback attractors for non compact random dynamical systems
Journal of Differential Equations, 2012Co-Authors: Bixiang WangAbstract:Abstract We study Pullback attractors of non-autonomous non-compact dynamical systems generated by differential equations with non-autonomous deterministic as well as stochastic forcing terms. We first introduce the concepts of Pullback attractors and asymptotic compactness for such systems. We then prove a sufficient and necessary condition for existence of Pullback attractors. We also introduce the concept of complete orbits for this sort of systems and use these special solutions to characterize the structures of Pullback attractors. For random systems containing periodic deterministic forcing terms, we show the Pullback attractors are also periodic under certain conditions. As an application of the abstract theory, we prove the existence of a unique Pullback attractor for Reaction–Diffusion equations on R n with both deterministic and random external terms. Since Sobolev embeddings are not compact on unbounded domains, the uniform estimates on the tails of solutions are employed to establish the asymptotic compactness of solutions.
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sufficient and necessary criteria for existence of Pullback attractors for non compact random dynamical systems
arXiv: Analysis of PDEs, 2012Co-Authors: Bixiang WangAbstract:We study Pullback attractors of non-autonomous non-compact dynamical systems generated by differential equations with non-autonomous deterministic as well as stochastic forcing terms. We first introduce the concepts of Pullback attractors and asymptotic compactness for such systems. We then prove a sufficient and necessary condition for existence of Pullback attractors. We also introduce the concept of complete orbits for this sort of systems and use these special solutions to characterize the structures of Pullback attractors. For random systems containing periodic deterministic forcing terms, we show the Pullback attractors are also periodic. As an application of the abstract theory, we prove the existence of a unique Pullback attractor for Reaction-Diffusion equations on $\R^n$ with both deterministic and random external terms. Since Sobolev embeddings are not compact on unbounded domains, the uniform estimates on the tails of solutions are employed to establish the asymptotic compactness of solutions.
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asymptotic behavior of stochastic wave equations with critical exponents on mathbb r 3
Transactions of the American Mathematical Society, 2011Co-Authors: Bixiang WangAbstract:The existence of a random attractor in H 1 (ℝ 3 ) x L 2 (ℝ 3 ) is proved for the damped semilinear stochastic wave equation defined on the entire space ℝ 3 . The nonlinearity is allowed to have a cubic growth rate which is referred to as the critical exponent. The uniform Pullback estimates on the tails of solutions for large space variables are established. The Pullback asymptotic compactness of the random dynamical system is proved by using these tail estimates and the energy equation method.
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Pullback attractors for non autonomous reaction diffusion equations on ℝn
Frontiers of Mathematics in China, 2009Co-Authors: Bixiang WangAbstract:We study the long time behavior of solutions of the non-autonomous reaction-diffusion equation defined on the entire space ℝn when external terms are unbounded in a phase space. The existence of a Pullback global attractor for the equation is established in L2(ℝn) and H1(ℝn), respectively. The Pullback asymptotic compactness of solutions is proved by using uniform a priori estimates on the tails of solutions outside bounded domains.
