subject:(viscoelasticity imaging)

Cornell University

1. Aguilo, Miguel. Inverse Strategies For Characterization Of Material Properties.

Degree: PhD, Civil and Environmental Engineering, 2011, Cornell University

► The imaging of constitutive parameters is of interest in many science and engineering fields. Indeed, non-invasive and nondestructive techniques are used to characterize key properties… (more)

▼ The imaging of constitutive parameters is of interest in many science and engineering fields. Indeed, non-invasive and nondestructive techniques are used to characterize key properties of a system given its response due to an external excitation. Then, assuming a priori a given model of the system, the measured response and an inverse approach are used to identify material properties. This work was undertaken in the context of identification of spatially-varying elastic and viscoelastic parameters of solids using vibroacoustics based techniques. Two optimization approaches, nongradient and gradient-based optimization, were investigated in this work. Initially, nongradient-based algorithms were preferred over gradient-based algorithms because of there ability to find global minima irrespective of initial guesses. For instance, Gaussian radial basis functions were used to construct a finite-dimensional representation of the elastic moduli. Then, an inverse approach was used to approximate the spatiallyvarying elastic moduli through the system response induced by the radiation force of ultrasound. The inverse problem was cast as an optimization problem in which a least-square error functional that quantified the misfit between the experimental and finite element representation system response is minimized by searching over a space of admissible vectors that best describe the spatial distribution of the elastic moduli. Subsequently, gradient-based optimization was preferred over nongradient-based optimization as the number of design variables increased due to the increment in computational cost. Two inverse approaches, L2-adjoint and concept of error in constitutive equation, were investigated in the context of gradient-based optimization. First, the L2-adjoint inverse approach was used to characterize spatially-varying viscoelastic properties because of its advantage to efficiently calculate the gradient of the error functional with respect to the design variables by solving the corresponding adjoint equations. The inverse problem was cast as an optimization problem in which a least-square error functional that quantified the misfit between the experimental and the finite element representation system response is minimized by searching over a space of admissible functions that best describe the spatially-varying viscoelastic properties. Given that the least-square error functional is non-convex, an inverse approach based on the concept of error in constitutive equation was investigated. The convexity property of the error in constitutive equation functionals, shown extensively for elliptic boundary value problems, reduce the sensitivity of the inverse solution to parameter initialization. The inverse problem was cast as an optimization problem in which an error in constitutive equation functional that quantified the misfit between the kinematically and dynamically admissible stress fields is minimized by searching over a space of admissible functions that best describe the spatially-varying viscoelastic properties.… Advisors/Committee Members: Aquino, Wilkins (chair), Mukherjee, Subrata (committee member), Ingraffea, Anthony R (committee member), Bonassar, Lawrence (committee member).

Subjects/Keywords: viscoelasticity imaging; inverse problem; vibroacoustography

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APA (6^th Edition):

Aguilo, M. (2011). Inverse Strategies For Characterization Of Material Properties. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/33569

Chicago Manual of Style (16^th Edition):

Aguilo, Miguel. “Inverse Strategies For Characterization Of Material Properties.” 2011. Doctoral Dissertation, Cornell University. Accessed March 06, 2021. http://hdl.handle.net/1813/33569.

MLA Handbook (7^th Edition):

Aguilo, Miguel. “Inverse Strategies For Characterization Of Material Properties.” 2011. Web. 06 Mar 2021.

Vancouver:

Aguilo M. Inverse Strategies For Characterization Of Material Properties. [Internet] [Doctoral dissertation]. Cornell University; 2011. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1813/33569.

Council of Science Editors:

Aguilo M. Inverse Strategies For Characterization Of Material Properties. [Doctoral Dissertation]. Cornell University; 2011. Available from: http://hdl.handle.net/1813/33569

Rutgers University

2. Zhao, Xiaodong. Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation.

Degree: PhD, Mechanical and Aerospace Engineering, 2015, Rutgers University

URL: https://rucore.libraries.rutgers.edu/rutgers-lib/48743/

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Biomechanical imaging techniques based on acoustic radiation force (ARF) have been developed to characterize the viscoelasticity of soft tissue by measuring the motion induced with… (more)

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Biomechanical imaging techniques based on acoustic radiation force (ARF) have been developed to characterize the viscoelasticity of soft tissue by measuring the motion induced with ARF noninvasively. The unknown stress distribution in the region of excitation (ROE) limits an accurate inverse characterization of soft tissue viscoelasticity. Thus, many assumptions have been made for both qualitative and quantitative ARF imaging within the ROE. In this thesis, the finite element method is applied to study the dynamic behavior of soft tissue in ARF imaging within the ROE to investigate the assumptions that are made in these imaging methods and decide what factors affect the accuracy of these assumptions. To this end, the effects of global boundary conditions and local heterogeneity are investigated, and simplified quantitative inversion model is evaluated for their limitations in describing soft tissue dynamic behavior. In order to improve quantitative estimation within the ROE, an inverse finite element (FE) characterization procedure based on a Bayesian formulation is presented, which takes full advantage of the prior information of the imaging system that are discarded in the simplified inversion models. The Bayesian approach formulates the known model parameters of the FE models as probability distributions, and aims to estimate a reasonable quantification of the probability distributions of soft tissue mechanical properties rather than best-fit values from an optimization procedure, which are not a practical or a comprehensive description of the estimation in the presence of measurement noise and model parameter uncertainty. To make the Bayesian approach computationally feasible, the Gaussian Process metamodeling method is applied as a statistical approximation of the complex FE model. A comprehensive numerical study in ARF induced creep imaging shows that the Bayesian approach with FE model improves the estimation results even in the presence of large uncertainty levels of the model parameters and provides a potential to improve the ROE-response-based imaging methods where the unknown stress limits an accurate inverse FE characterization.

Advisors/Committee Members: Pelegri, Assimina A. (chair), Cuitino, Alberto (internal member), WENG, GEORGE (internal member), LaMattina, Bruce (outside member).

Subjects/Keywords: Acoustic radiation force impulse imaging; Viscoelasticity

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APA (6^th Edition):

Zhao, X. (2015). Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/48743/

Chicago Manual of Style (16^th Edition):

Zhao, Xiaodong. “Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation.” 2015. Doctoral Dissertation, Rutgers University. Accessed March 06, 2021. https://rucore.libraries.rutgers.edu/rutgers-lib/48743/.

MLA Handbook (7^th Edition):

Zhao, Xiaodong. “Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation.” 2015. Web. 06 Mar 2021.

Vancouver:

Zhao X. Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation. [Internet] [Doctoral dissertation]. Rutgers University; 2015. [cited 2021 Mar 06]. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/48743/.

Council of Science Editors:

Zhao X. Finite element characterization of soft tissue viscoelastic parameters in acoustic radiation force imaging within the region of excitation. [Doctoral Dissertation]. Rutgers University; 2015. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/48743/

University of New South Wales

3. Qin, Eric Chuan. Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging.

Degree: Clinical School - Prince of Wales Hospital, 2012, University of New South Wales

URL: http://handle.unsw.edu.au/1959.4/52341 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:11014/SOURCE01?view=true

► An abnormal change in muscle mechanical properties is usually indicative of disease or injury. In this thesis, the in vivo anisotropic mechanical properties of skeletal… (more)

▼ An abnormal change in muscle mechanical properties is usually indicative of disease or injury. In this thesis, the in vivo anisotropic mechanical properties of skeletal muscles were investigated non-invasively using a combined medical imaging modality - magnetic resonance elastography (MRE) combined with diffusion tensor imaging (DTI). By assuming a transversely isotropic model, the shear modulus parallel (μ║) and perpendicular (μ┴) to the local fibre orientation, as well as the anisotropic ratio (μ║/ μ┴), were calculated. DTI provided the local fibre direction in anisotropic materials based on the diffusion of water molecules. Experiments were conducted in ex vivo phantoms and bovine muscle samples, an in vivo mouse model, and in vivo human subjects. Results from these studies showed that this combined MRE/DTI imaging method was capable of visualizing and quantifying the anisotropic shear moduli (µ║, µ┴) and detecting changes in the mechanical anisotropic ratio (µ║/µ┴) in ex vivo phantoms and in vivo skeletal muscles. Specifically, the phantom results showed that the MRE/DTI technique was able to differentiate various levels of anisotropy, and the results correlated well with the gold standard rheometry tests. Moreover, in vivo animal results indicate that this technique can detect changes in muscle mechanical anisotropy due to necrosis, consistent with histological findings. Finally, in an in vivo human study, it was demonstrated that the mechanical anisotropy ratio can be used to track the physiological response of skeletal muscle after eccentric exercise. Overall, these results have shown that the mechanical anisotropy ratio (µ║/µ┴) has potential as an imaging biomarker for detecting pathological and physiological changes in skeletal muscle in vivo, and the MRE/DTI technique can be used to accurately measure this tissue anisotropic mechanical property non-invasively. Advisors/Committee Members: Bilston, Lynne, Neuroscience Research Australia, UNSW.

Subjects/Keywords: Elastography; Muscle; Medical imaging; Diffusion tensor imaging; Viscoelasticity; Anisotropy; MRI

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APA (6^th Edition):

Qin, E. C. (2012). Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/52341 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:11014/SOURCE01?view=true

Chicago Manual of Style (16^th Edition):

Qin, Eric Chuan. “Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging.” 2012. Doctoral Dissertation, University of New South Wales. Accessed March 06, 2021. http://handle.unsw.edu.au/1959.4/52341 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:11014/SOURCE01?view=true.

MLA Handbook (7^th Edition):

Qin, Eric Chuan. “Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging.” 2012. Web. 06 Mar 2021.

Vancouver:

Qin EC. Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging. [Internet] [Doctoral dissertation]. University of New South Wales; 2012. [cited 2021 Mar 06]. Available from: http://handle.unsw.edu.au/1959.4/52341 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:11014/SOURCE01?view=true.

Council of Science Editors:

Qin EC. Investigating the anisotropic mechanical properties of skeletal muscle using magnetic resonance elastography and diffusion tensor imaging. [Doctoral Dissertation]. University of New South Wales; 2012. Available from: http://handle.unsw.edu.au/1959.4/52341 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:11014/SOURCE01?view=true

Cornell University

4. Diaz Martinez, Manuel. A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data.

Degree: PhD, Civil and Environmental Engineering, 2015, Cornell University

URL: http://hdl.handle.net/1813/39382

► This thesis presents the formulation and implementation details of a method based on the modified error in constitutive equation to address the viscoelasticity imaging problem… (more)

▼ This thesis presents the formulation and implementation details of a method based on the modified error in constitutive equation to address the viscoelasticity imaging problem in situations in which information on boundary conditions is unknown. In the viscoelasticity imaging problem, the goal is to produce images of the viscoelastic properties of a material from displacements measured in its interior. These measured displacements are always corrupted with noise, which poses a challenge to methods designed to solve such problems. Moreover, in practical applications such as biomedical imaging, where the material of interest is tissue, the magnitude and spatial distribution of the excitation used to generate the displacements that are measured are not exactly known. This is a challenge to optimization-based methods for the imaging problem, as the lack of boundary conditions leads to ill-posed forward problems. The method developed here overcomes this challenge and at the same time handles noisy and incomplete displacement data. This thesis is divided into two chapters. The first chapter, which is an adaptation of a journal article that has been submitted for publication, presents the method and relevant derivations. Results from numerical experiments are also included in this chapter. The second chapter details the implementation of the method in the DinamicaE simulation suite, developed by the Computational Mechanics and Inverse Problems Group led by Professor Wilkins Aquino. The DinamicaE simulation suite is the result of over four years of development effort, which is still ongoing. Development of a large component of this software has been one of the author's main contributions as a Ph.D. student. DinamicaE is a massively parallel research code that solves problems in steady-state dynamics, acoustics, and acoustic-structure interaction. Moreover, the software also solves imaging problems in these domains. One of the main goals of DinamicaE is to assess the feasibility of algorithms such as the one presented in this thesis to solve problems of interest in the field of biomedical imaging, which seeks to provide early diagnosis for many physical illnesses. Its modular design, which is made possible by the features offered by the C++ programming language, allows for simple implementations of the algorithm presented in this thesis and many more. Advisors/Committee Members: Warner, Derek H. (chair), Earls, Christopher J (committee member), Bindel, David S. (committee member), Aquino, Wilkins (committee member).

Subjects/Keywords: inverse problems; elasticity imaging; viscoelasticity; materials identification; optimization

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Diaz Martinez, M. (2015). A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/39382

Chicago Manual of Style (16^th Edition):

Diaz Martinez, Manuel. “A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data.” 2015. Doctoral Dissertation, Cornell University. Accessed March 06, 2021. http://hdl.handle.net/1813/39382.

MLA Handbook (7^th Edition):

Diaz Martinez, Manuel. “A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data.” 2015. Web. 06 Mar 2021.

Vancouver:

Diaz Martinez M. A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data. [Internet] [Doctoral dissertation]. Cornell University; 2015. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1813/39382.

Council of Science Editors:

Diaz Martinez M. A Modified Error In Constitutive Equation Approach For Viscoelasticity Imaging With Interior Data. [Doctoral Dissertation]. Cornell University; 2015. Available from: http://hdl.handle.net/1813/39382

Boston University

5. Yengul, Sanjay S. Shear wave rheometry with applications in elastography.

Degree: PhD, Mechanical Engineering, 2019, Boston University

URL: http://hdl.handle.net/2144/34923

► The goal of elastography is to map the mechanical properties of soft tissues associated with health and disease. The mechanical property of interest in this… (more)

▼ The goal of elastography is to map the mechanical properties of soft tissues associated with health and disease. The mechanical property of interest in this work is the complex shear modulus, composed of a real part, the storage modulus, which is a measure of elasticity, and an imaginary part, the loss modulus, which is a measure of viscosity. Together, they determine the speed and attenuation of shear waves in the medium. Elastography techniques based on either ultrasound imaging or MRI can image shear wave propagation and thus are capable of measuring shear wave speed and attenuation. Dispersion, or the frequency-dependence of material parameters, is a primary confounding factor when comparing measurements between different shear wave elastography implementations. Prior attempts at quantifying this frequency-dependence suffered from inaccurate modeling assumptions and low signal-to-noise ratios (SNR). To overcome these limitations, a high-fidelity forward model of shear wave propagation in homogeneous media was developed. The model is an exact semi-analytical solution of Navier's equation and is well-suited for acoustic radiation force impulse shear wave elastography (ARFI-SWE) because it does not require precise knowledge of the strength of the source, nor its spatial or temporal distribution. Unlike models used in ARFI-SWE heretofore, it accounts for the vector polarization of shear waves and exactly represents geometric spreading of the shear wavefield, whether spherical, cylindrical, or neither. Furthermore, it is material-model independent, i.e. it makes no assumption about the frequency-dependence of material parameters. It overcomes the problem of low SNR through spatial averaging and enables estimation of the frequency-dependent complex shear modulus over a wider frequency range than has hitherto been possible. This improved ARFI-SWE was named Shear Wave Rheometry (SWR). By combining SWR with a novel torsional vibration rheometry, dispersion in tissue-mimicking gels was quantified from 1 – 1800 Hz. The measurements show sizable frequency-dependent variation in the shear modulus of gelatin, a material often assumed to be non-dispersive based on narrow-band measurements. SWR measurements in ex vivo bovine liver tissue yielded complex shear modulus estimates from 25 – 250 Hz and showed that liver tissue exhibits significant dispersion in this frequency range: a factor of 4 increase in the storage modulus and a factor of 10 increase in the loss modulus. Quality metrics showed that liver tissue can be reasonably approximated as homogeneous and isotropic for ARFI-SWE measurements in this frequency range. Results demonstrate that accounting for dispersion is essential for meaningful comparisons of measurements between systems. Moreover, improved tissue characterization enabled by SWR may have clinical relevance, for example, in the diagnosis and monitoring of chronic liver disease. Advisors/Committee Members: Barbone, Paul E. (advisor), Madore, Bruno (advisor).

Subjects/Keywords: Acoustics; Elastic wave; Liver fibrosis; Medical imaging; NAFLD; Steatosis; Viscoelasticity

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APA (6^th Edition):

Yengul, S. S. (2019). Shear wave rheometry with applications in elastography. (Doctoral Dissertation). Boston University. Retrieved from http://hdl.handle.net/2144/34923

Chicago Manual of Style (16^th Edition):

Yengul, Sanjay S. “Shear wave rheometry with applications in elastography.” 2019. Doctoral Dissertation, Boston University. Accessed March 06, 2021. http://hdl.handle.net/2144/34923.

MLA Handbook (7^th Edition):

Yengul, Sanjay S. “Shear wave rheometry with applications in elastography.” 2019. Web. 06 Mar 2021.

Vancouver:

Yengul SS. Shear wave rheometry with applications in elastography. [Internet] [Doctoral dissertation]. Boston University; 2019. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/2144/34923.

Council of Science Editors:

Yengul SS. Shear wave rheometry with applications in elastography. [Doctoral Dissertation]. Boston University; 2019. Available from: http://hdl.handle.net/2144/34923

University of Rochester

6. Langdon, Jonathan H. Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues.

Degree: PhD, 2016, University of Rochester

URL: http://hdl.handle.net/1802/30602

► In response to chronic inflammation, many tissues undergo a transformation known as fibrosis that results in increased stiffness of the tissue. The parenchyma of the… (more)

Subjects/Keywords: Acoustic radiation force; Computational methods; Elastography; Finite difference time domain; Shear wave imaging; Viscoelasticity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Langdon, J. H. (2016). Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues. (Doctoral Dissertation). University of Rochester. Retrieved from http://hdl.handle.net/1802/30602

Chicago Manual of Style (16^th Edition):

Langdon, Jonathan H. “Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues.” 2016. Doctoral Dissertation, University of Rochester. Accessed March 06, 2021. http://hdl.handle.net/1802/30602.

MLA Handbook (7^th Edition):

Langdon, Jonathan H. “Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues.” 2016. Web. 06 Mar 2021.

Vancouver:

Langdon JH. Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues. [Internet] [Doctoral dissertation]. University of Rochester; 2016. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1802/30602.

Council of Science Editors:

Langdon JH. Development of single track location shear wave viscoelasticity imaging for real-time characterization of biological tissues. [Doctoral Dissertation]. University of Rochester; 2016. Available from: http://hdl.handle.net/1802/30602

Texas A&M University

7. Meng, Zhaokai. Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes.

Degree: PhD, Biomedical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/157098

► The tremendous progress in life sciences and medicine has been greatly facilitated by the development of new imaging modalities. The elastic properties of molecules, subcellular… (more)

▼ The tremendous progress in life sciences and medicine has been greatly facilitated by the development of new imaging modalities. The elastic properties of molecules, subcellular and cellular structures play a crucial role in many areas of biology and medicine. Tissue elasticity has recently been recognized as a critical regulator of cell behavior, with clear roles in embryogenesis, tissue morphogenesis and stem cell differentiation, as well as contributing to pathologies such as tumor progression, coronary artery disease and tissue scarring. This dissertation is focused on developing a novel instrumentation to image viscoelastic properties of cells and tissues using Brillouin microspectroscopy. Following design, construction and optimizations that maximize the signal quality, we obtained the highest resolution Brillouin imaging system in a confocal backscattering arrangement suitable for bio-imaging applications. Furthermore, a powerful combination of Brillouin and Raman spectroscopies has yielded a confocal microscope capable of performing simultaneous mechanical and chemical imaging in a non-invasive and noncontact manner. The novel instrument was optimized and validated for several biomedical applications. For example, we demonstrated that Brillouin spectroscopy is capable of performing in-vivo measurements of the mechanical properties of artificial biocompatible materials such as photocrosslinkable gelatin methacrylate (GelMA). With the assistance of animal models of human congenital muscular dystrophies, we show that Brillouin spectroscopy can serve as a unique diagnosis tool, which can detect differences in muscle elasticity even between very similar muscular dystrophy genotypes. We have also demonstrated that Brillouin spectroscopy is an invaluable approach in developmental biology since it is capable of making non-destructive imaging of an embryo's elasticity during its development process, which is crucial to understand the formation of many essential organs such as bone and brain. In summary, we have developed a novel instrument for biomedical imaging sensing, which is compatible with other microscopic imaging modalities and is specific to local elasticity. Numerous applications of this new technology have been explored, and the instrument’s performance was validated for several systems. Advisors/Committee Members: Yakovlev, Vladislav V (advisor), Applegate, Brian E (committee member), Jo, Javier A (committee member), Sokolov, Alexei V (committee member).

Subjects/Keywords: Brillouin spectroscopy; Optical scattering; Optical spectroscopy; Biomechanics; Mechanobiology; Biomedical imaging; microscopic viscoelasticity; developmental biology; Biomaterial

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APA (6^th Edition):

Meng, Z. (2016). Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157098

Chicago Manual of Style (16^th Edition):

Meng, Zhaokai. “Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes.” 2016. Doctoral Dissertation, Texas A&M University. Accessed March 06, 2021. http://hdl.handle.net/1969.1/157098.

MLA Handbook (7^th Edition):

Meng, Zhaokai. “Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes.” 2016. Web. 06 Mar 2021.

Vancouver:

Meng Z. Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1969.1/157098.

Council of Science Editors:

Meng Z. Non-Destructive Viscoelasticity Microscopy: A Spectroscopic Approach using Dual Brillouin/Raman Scattering Processes. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/157098

University of Michigan

8. Hong, Xiaowei. Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues.

Degree: PhD, Biomedical Engineering, 2018, University of Michigan

URL: http://hdl.handle.net/2027.42/144116

► Mechanobiology is central in the development, pathology, and regeneration of musculoskeletal tissues, in which mechanical factors play important roles. Therefore, there is a need for… (more)

▼ Mechanobiology is central in the development, pathology, and regeneration of musculoskeletal tissues, in which mechanical factors play important roles. Therefore, there is a need for methods to characterize the composition and mechanical properties of developing musculoskeletal tissues over time. Ultrasound elastographic techniques have been developed for noninvasive imaging of spatial heterogeneity in tissue stiffness. However, their application for quantitative assessment of tissue mechanical properties, especially viscoelastic properties, has not been exploited. Additionally, ultrasound energy may be used to apply mechanical stimulation to engineered constructs at the microscale, and thereby to enhance tissue regeneration. We have developed a multimode ultrasound viscoelastography (MUVE) system for assessing microscale mechanical properties of engineered hydrogels. MUVE uses focused ultrasound pulses to apply acoustic radiation force (ARF) to deform samples, while concurrently measuring sample dimensions using coaxial high frequency ultrasound imaging. We used MUVE to perform creep tests on agarose, collagen, and fibrin hydrogels of defined concentrations, as well as to monitor the mechanical properties of cell-seeded constructs over time. Local and bulk viscoelastic properties were extracted from strain-time curves through fitting of relevant constitutive models, showing clear differences between concentrations and materials. In particular, we showed that MUVE is capable of mapping heterogeneity of samples in 3D. Using inclusion of dense agarose microbeads within agarose, collagen and fibrin hydrogels, we determined the spatial resolution of MUVE to be approximately 200 μm in both the lateral and axial directions. Comparison of MUVE to nanoindentation and shear rheometry showed that our ultrasound-based technique was superior in generating consistent, microscale data, particularly for very soft materials. We have also adapted MUVE to generate localized cyclic compression, as a means to mechanically stimulate engineered tissue constructs at the microscale. Selected treatment protocols were shown to enhance the osteogenic differentiation of human mesenchymal stem cells in collagen-fibrin hydrogels. Constructs treated at 1 Hz at an acoustic pressure of 0.7 MPa for 30 minutes per day showed accelerated osteogenesis and increased mineralization by 10 to 30 percent, relative to unstimulated controls. In separate experiments, the ultrasound pulse intensity was increased over time to compensate for changes in matrix properties over time, and a 35 percent increase in mineralization was achieved. We also extended the application of a previously-developed spectral ultrasound imaging (SUSI) technique to an animal model for early detection of heterotopic ossification (HO). The quantitative information on acoustic scatterer size and concentration derived from SUSI was used to differentiate tissue composition in a burn/tenotomy mice model from the control model. Importantly, HO foci were detected as early as one week after… Advisors/Committee Members: Deng, Cheri Xiaoyu (committee member), Stegemann, Jan Philip (committee member), Fowlkes, Jeffrey Brian (committee member), Coleman, Rhima M (committee member).

Subjects/Keywords: ultrasound elastography; ultrasound mechanical stimulation; ultrasound compositional imaging; quantitative ultrasound; soft material viscoelasticity; Biomedical Engineering; Engineering

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APA (6^th Edition):

Hong, X. (2018). Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/144116

Chicago Manual of Style (16^th Edition):

Hong, Xiaowei. “Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues.” 2018. Doctoral Dissertation, University of Michigan. Accessed March 06, 2021. http://hdl.handle.net/2027.42/144116.

MLA Handbook (7^th Edition):

Hong, Xiaowei. “Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues.” 2018. Web. 06 Mar 2021.

Vancouver:

Hong X. Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/2027.42/144116.

Council of Science Editors:

Hong X. Development and Applications of Advanced Ultrasound Techniques for Characterization and Stimulation of Engineered Tissues. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/144116

Michigan State University

9. Yang, Yiqun. Shear elasticity and shear viscosity imaging in soft tissue.

Degree: 2018, Michigan State University

URL: http://etd.lib.msu.edu/islandora/object/etd:6990

► "In this thesis, a new approach is introduced that provides estimates of shear elasticity and shear viscosity using time-domain measurements of shear waves in viscoelastic… (more)

▼ "In this thesis, a new approach is introduced that provides estimates of shear elasticity and shear viscosity using time-domain measurements of shear waves in viscoelastic media. Simulations of shear wave particle displacements induced by an acoustic radiation force are accelerated significantly by a GPU. The acoustic radiation force is first calculated using the fast near field method (FNM) and the angular spectrum approach (ASA). The shear waves induced by the acoustic radiation force are then simulated in elastic and viscoelastic media using Green's functions. A parallel algorithm is developed to perform these calculations on a GPU, where the shear wave particle displacements at different observation points are calculated in parallel. The resulting speed increase enables rapid evaluation of shear waves at discrete points, in 2D planes, and for push beams with different spatial samplings and for different values of the f-number (f/#). The results of these simulations show that push beams with smaller f/# require a higher spatial sampling rate. The significant amount of acceleration achieved by this approach suggests that shear wave simulations with the Green's function approach are ideally suited for high-performance GPUs. Shear wave elasticity imaging determines the mechanical parameters of soft tissue by analyzing measured shear waves induced by an acoustic radiation force. To estimate the shear elasticity value, the widely used time-of-flight (TOF) method calculates the correlation between shear wave particle velocities at adjacent lateral observation points. Although this method provides accurate estimates of the shear elasticity in purely elastic media, our experience suggests that the TOF method consistently overestimates the shear elasticity values in viscoelastic media because the combined effects of diffraction, attenuation, and dispersion are not considered. To address this problem, we have developed an approach that directly accounts for all of these effects when estimating the shear elasticity. This new approach simulates shear wave particle velocities using a Green's function-based approach for the Voigt model, where the shear elasticity and viscosity values are estimated using an optimization-based approach that compares measured shear wave particle velocities with simulated shear wave particle velocities in the time-domain. The results are evaluated on a point-by-point basis to generate images. There is good agreement between the simulated and measured shear wave particle velocities, where the new approach yields much better images of the shear elasticity and shear viscosity than the TOF method. The new estimation approach is accelerated with an approximate viscoelastic Green's function model that is evaluated with shear wave data obtained from in vivo human livers. Instead of calculating shear waves with combinations of different shear elasticities and shear viscosities, shear waves are calculated with different shear elasticities on the GPU and then convolved with a viscous loss model, which… Advisors/Committee Members: McGough, Robert J, Baek, Seungik, Feeny, Brian F, Udpa, Lalita.

Subjects/Keywords: Viscoelasticity – Mathematical models; Shear waves – Simulation methods; Acoustic radiation force impulse imaging; Shear waves – Mathematical models; Biomedical engineering; Acoustics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Yang, Y. (2018). Shear elasticity and shear viscosity imaging in soft tissue. (Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:6990

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Yang, Yiqun. “Shear elasticity and shear viscosity imaging in soft tissue.” 2018. Thesis, Michigan State University. Accessed March 06, 2021. http://etd.lib.msu.edu/islandora/object/etd:6990.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Yang, Yiqun. “Shear elasticity and shear viscosity imaging in soft tissue.” 2018. Web. 06 Mar 2021.

Vancouver:

Yang Y. Shear elasticity and shear viscosity imaging in soft tissue. [Internet] [Thesis]. Michigan State University; 2018. [cited 2021 Mar 06]. Available from: http://etd.lib.msu.edu/islandora/object/etd:6990.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Yang Y. Shear elasticity and shear viscosity imaging in soft tissue. [Thesis]. Michigan State University; 2018. Available from: http://etd.lib.msu.edu/islandora/object/etd:6990

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Illinois – Chicago

10. Burns, David A. Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography.

Degree: 2015, University of Illinois – Chicago

URL: http://hdl.handle.net/10027/19354

► The mechanical stiffness properties of biological tissue can be useful in the detection and diagnosis of disease, historically obtained through manual palpation. Magnetic Resonance Elastography… (more)

Subjects/Keywords: Magnetic Resonance; Elastography; Magnetic Resonance Imaging; Viscoelasticity; Mechanical Wave Theory; Lame Parameter; Elastogram; Stiffness; Clinical Imaging; Pulse Sequence Programming; Siemens IDEA; Motion Encoding Gradients

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Burns, D. A. (2015). Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/19354

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Burns, David A. “Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography.” 2015. Thesis, University of Illinois – Chicago. Accessed March 06, 2021. http://hdl.handle.net/10027/19354.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Burns, David A. “Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography.” 2015. Web. 06 Mar 2021.

Vancouver:

Burns DA. Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography. [Internet] [Thesis]. University of Illinois – Chicago; 2015. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10027/19354.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Burns DA. Synchronous Multi-Directional Motion Encoding in Magnetic Resonance Elastography. [Thesis]. University of Illinois – Chicago; 2015. Available from: http://hdl.handle.net/10027/19354

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

11. Héraud, Sandrine. Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration.

Degree: Docteur es, Biologie cellulaire et tissulaire, 2015, Université Claude Bernard – Lyon I

URL: http://www.theses.fr/2015LYO10307

►

On entend par substitut dermo-épidermique un épiderme reconstruit à la surface d'un derme équivalent composé de fibroblastes cultivés classiquement dans un biomatériau support, souvent à… (more)

▼

On entend par substitut dermo-épidermique un épiderme reconstruit à la surface d'un derme équivalent composé de fibroblastes cultivés classiquement dans un biomatériau support, souvent à base de collagène poreux ou sous forme de gel. Ce support possède ses propres propriétés biomécaniques, influant sur la réponse biomécanique globale des peaux reconstruites, nous nous sommes donc intéressés à un modèle de peau reconstruite sans support, dans lequel le derme équivalent est « auto-assemblé » par les fibroblastes néosynthétisant leur propre matrice extracellulaire (MEC). Notre premier objectif a été d'optimiser et de caractériser ce modèle auto-assemblé en termes de structure, de reproductibilité et de fonctionnalité. Notre second objectif a été d'adapter aux peaux reconstruites in vitro (PR) des outils traditionnellement utilisés pour des études in vivo, pour explorer leurs propriétés biophysiques et biomécaniques. Ces outils permettent une exploration morphologique à des résolutions différentes avec l'échographie, la tomographie à cohérence optique (OCT) et la microscopie confocale à balayage et une exploration fonctionnelle des propriétés biomécaniques des PR par cutométrie. Ces données biophysiques ont ensuite été analysées par rapport aux résultats en histologie, immunohistologie et microscopie électronique à transmission. La cinétique de culture du modèle auto-assemblé sur un temps prolongé a montré la grande stabilité de l'épiderme et le remodelage continuel de la MEC avec notamment l'augmentation des fibres de collagène et d'élastine. Au temps de culture de référence sélectionné, correspondant à l'obtention de la différenciation terminale de l'épiderme, nous avons démontré la reproductibilité des épaisseurs de l'épiderme et du derme en histologie et en OCT, de la maturité de l'épiderme et de la jonction dermo-épidermique et de l'expression dermique de l'élastine colocalisée avec la fibrilline. Sur le plan fonctionnel, nous avons démontré la fonction barrière de l'épiderme via l'imperméabilité du stratum corneum et des jonctions serrées

A skin equivalent consist of a epidermis reconstructed on the top of a dermis equivalent classically composed of fibroblasts cultured into a biomaterial scaffold which is often a collagen gel or sponge. This scaffold hold its own mechanical properties, influencing the global skin equivalent biomechanical response, so we choose to develop a scaffold-free skin equivalent (SFSE), based on the ability of fibroblasts to synthezise their own extracellular matrix. Our first objective was to optimize and characterize the structure, the reproducibility and functionality of this scaffold-free model. Our second goal was to adapt biophysical and biomechanical tools classically used for in vivo evaluation to in vitro skin equivalents. Their morphology was explored with different resolutions using echography, optical coherence tomography (OCT) and laser scanning microscopy whereas biomechanical functionality was evaluate by a suction test, the cutometry. This biophysical data were compared…

Advisors/Committee Members: Damour, Odile (thesis director).

Subjects/Keywords: Peau reconstruite humaine; In vitro; Matrice extracellulaire; Propriétés biomécaniques; Viscoélasticité; Imagerie; Human skin equivalent; In vitro; Extracellular matrix; Biomechanical properties; Viscoelasticity; Imaging; 611

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Héraud, S. (2015). Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration. (Doctoral Dissertation). Université Claude Bernard – Lyon I. Retrieved from http://www.theses.fr/2015LYO10307

Chicago Manual of Style (16^th Edition):

Héraud, Sandrine. “Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration.” 2015. Doctoral Dissertation, Université Claude Bernard – Lyon I. Accessed March 06, 2021. http://www.theses.fr/2015LYO10307.

MLA Handbook (7^th Edition):

Héraud, Sandrine. “Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration.” 2015. Web. 06 Mar 2021.

Vancouver:

Héraud S. Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration. [Internet] [Doctoral dissertation]. Université Claude Bernard – Lyon I; 2015. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2015LYO10307.

Council of Science Editors:

Héraud S. Adaptation de méthodes biophysiques et biomécaniques pour l'exploration des peaux reconstruites in vitro : Adaptation of biophysical and biomechanical methods for in vitro skin equivalent exploration. [Doctoral Dissertation]. Université Claude Bernard – Lyon I; 2015. Available from: http://www.theses.fr/2015LYO10307

12. Vieira, Silvio Leão. Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom.

Degree: PhD, Física Aplicada à Medicina e Biologia, 2009, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22042010-093544/ ;

►

Em tecidos biológicos lesados, a viscoelasticidade é a propriedade física que mais se modifica em relação ao tecido normal. Palpação manual é geralmente usada para… (more)

▼

Em tecidos biológicos lesados, a viscoelasticidade é a propriedade física que mais se modifica em relação ao tecido normal. Palpação manual é geralmente usada para identificar estas lesões, tais como nódulos e cistos. Recentemente, vários estudos envolvendo técnicas ultrassônicas e de ressonância magnética, denominadas elastografia, têm sido empregadas para avaliar as propriedades viscoelásticas dessas lesões. Uma das dificuldades neste tipo de estudo está relacionada ao desenvolvimento de simuladores de tecidos biológicos com inclusões equivalentes, uma vez que, essas estruturas lesadas originam-se a partir do próprio tecido biológico. Com base nessas motivações, técnicas quantitativas de elastografia por ressonância magnética e ultrassom foram exploradas para avaliar lesões simuladas em fantomas viscoelásticos. Estas lesões, com diferentes propriedades viscoelásticas, foram geradas no interior de um fantoma usando radiação ionizante. Os fantomas, também conhecidos como gel dosimétrico, foram desenvolvidos a base de pele animal, e irradiados utilizando um sistema de terapia de radiação convencional. Imagens de relaxometria por ressonância magnética (RRM) foram adquiridas nestes fantomas e usadas como referência padrão da dose absorvida e de sua distribuição. Os perfis da distribuição de dose avaliados nessas imagens de RRM e pelo sistema de planejamento radioterápico TPS 3D foram comparados aos de rigidez das imagens elastográficas. O estudo elastográfico nestes fantomas foi realizado utilizando os métodos de Vibroacustografia (VA), Vibrometria por Ultrassom (VU) e Elastografia por Ressonância Magnética (ERM). O segundo objetivo desta tese foi explorar a viabilidade de existência de speckle em imagens de vibroacustografia. Para testar essa idéia, um modelo tridimensional (3D) para a função de espalhamento de ponto (PSF) do sistema de VA foi simulada. O código da simulação foi desenvolvido em ambiente MATLAB e empregando sub-rotinas do programa Field II para simulação numérica dos transdutores. Imagens de ultrassom modo-B (IUSB) e vibroacustografia foram simuladas usando esse modelo de PSF-3D para um transdutor esférico e confocal, respectivamente. Essas IUSB foram simuladas para servir como um parâmetro comparativo com as imagens geradas por VA. As imagens de ultrassom foram exibidas em um plano tomográfico que corresponde ao plano de imagem da VA. As simulações foram realizadas utilizando um cluster de computadores de alto desempenho. Todas as imagens foram simuladas empregando um modelo de fantoma virtual não homogêneo com dimensões de (10 × 10 × 50) mm3. Os resultados preliminares mostraram um padrão de interferência nas imagens de VA, semelhantes à speckles, obtidas empregando o transdutor confocal. Estas imagens foram produzidas a partir de espalhadores localizados no interior do volume da célula de resolução da PSF-3D.

The viscoelasticity of injured biological tissues is the physical property that changes the most in relation to normal tissue. Manual palpation is commonly used to identify these lesions,…

Advisors/Committee Members: Carneiro, Antonio Adilton Oliveira.

Subjects/Keywords: Distribuição de Dose; Dose Distribution; Dosimeter Gel; Elastografia por Ressonância Magnética; Gel Dosimétrico; Magnetic Resonance Elastography; Shearwave Dispertion Ultrasound Vibrometry; Simulação de Imagem por Ultrassom.; Simulation of Ultrasound imaging.; Vibro-acustography; Vibroacustografia; Vibrometria por Força de Radiação Ultrassônica; Viscoelasticidade; Viscoelasticity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Vieira, S. L. (2009). Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22042010-093544/ ;

Chicago Manual of Style (16^th Edition):

Vieira, Silvio Leão. “Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom.” 2009. Doctoral Dissertation, University of São Paulo. Accessed March 06, 2021. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22042010-093544/ ;.

MLA Handbook (7^th Edition):

Vieira, Silvio Leão. “Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom.” 2009. Web. 06 Mar 2021.

Vancouver:

Vieira SL. Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom. [Internet] [Doctoral dissertation]. University of São Paulo; 2009. [cited 2021 Mar 06]. Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22042010-093544/ ;.

Council of Science Editors:

Vieira SL. Imagens das propriedades viscoelásticas por ressonância magnética e ultrassom. [Doctoral Dissertation]. University of São Paulo; 2009. Available from: http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22042010-093544/ ;

13. Alfasi, Abdulghader. Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury.

Degree: Human Anatomy and Cell Science, 2010, University of Manitoba

URL: http://hdl.handle.net/1993/4194

► Traumatic brain injury (TBI) has a 20% mortality rate and a 10-15% rate of resultant permanent disability. The consequences of TBI range from brief loss… (more)

▼ Traumatic brain injury (TBI) has a 20% mortality rate and a 10-15% rate of resultant permanent disability. The consequences of TBI range from brief loss of consciousness, to prolonged coma or death. Mild TBI is amongst the common causes of admission to trauma centers all over the world. Future technologies such as magnetic resonance elastography and robotic surgery demand information about the physical properties of brain tissue. Walsh and Schettini described the mechanical behavior of brain tissue under normal status as nonlinear viscoelastic behavior and defined the associated biomechanical changes and responses in a quantitative measurement of the material changes. Yet, there is still a lack of data concerning time-dependent deformation and mechanical property changes associated with TBI. My goal in this project was to describe these mechanical responses and to create a system for measuring and evaluating the mechanical response of brain tissue in vivo. This was to be achieved by inducing cortical contusions with a calibrated weight-drop method in seventy-four young adult male Sprague-Dawley rats. Instrumented indentation was performed on control brains and 1 hour to 3 weeks after contusion with intact dura using a 4-mm-diameter flat punch indenter to a maximum depth of 1.2 mm at loading. Loading rates did not exceed 0.34 N/min and 1.2 mm/min. In order to obtain force displacement data, we studied the elastic response of the traumatized brain tissue and the deformation process (creep) during the loading and unloading of indenter. After euthanasia, the brain was removed and evaluated histologically with different methods to reveal acute and chronic changes related to the contusion. The results revealed that the biomechanical properties of the brain tissue were changed after cortical contusion. Brain tissue elasticity decreased in the edematous brain at one day following the contusion and increased at 3 weeks, in association with reactive astroglial changes. This experimental technique, combined with mathematical modeling, might eventually lead to a better understanding of the physical changes in brain following TBI. Advisors/Committee Members: DelBigio, Marc (Pathology) (supervisor), Vrontakis, Maria (Human Anatomy and Cell Science) Schmidt, Brain (Physiology) (examiningcommittee).

Subjects/Keywords: Brain; Weight drop; Traumatic brain injury; Viscoelasticity; Evans Blue; Brain Edema; Indentation; Magnetic Resonance Imaging; Rat; Gliosis; Viscous; Elastic

…resonance imaging following intravenous administration of contrast (Marmarou et al. 2003)… …characteristics when exposed to deformation. Viscoelasticity is the result of the diffusion of atoms or… …viscoelastic materials can be classified as a small deformation or in terms of linear viscoelasticity… …deformation (non-linear) viscoelasticity. [22] 1.8. Basics of Indentation… …mechanical property termed “viscoelasticity behaviors” (Davis et al. 2006, Lakes et al. 2004…

10 more images…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Alfasi, A. (2010). Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/4194

Chicago Manual of Style (16^th Edition):

Alfasi, Abdulghader. “Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury.” 2010. Masters Thesis, University of Manitoba. Accessed March 06, 2021. http://hdl.handle.net/1993/4194.

MLA Handbook (7^th Edition):

Alfasi, Abdulghader. “Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury.” 2010. Web. 06 Mar 2021.

Vancouver:

Alfasi A. Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury. [Internet] [Masters thesis]. University of Manitoba; 2010. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1993/4194.

Council of Science Editors:

Alfasi A. Biomechanical Properties of Live Rat Brain Following Traumatic Brain Injury. [Masters Thesis]. University of Manitoba; 2010. Available from: http://hdl.handle.net/1993/4194

Université de Montréal

14. Tan, Ju Jing. Mechanosensitive ATP release in the lungs.

Degree: 2021, Université de Montréal

URL: http://hdl.handle.net/1866/24849

Subjects/Keywords: Bioluminescence de la luciférine-luciférase; Cellules alvéolaires; Contrainte mécanique; Imagerie d’ATP; Lésions pulmonaires induites par la ventilation mécanique; Mécanoporation; Relargage d'ATP; Signalisation purinergique; Viscoélasticité membranaire; Alveolar cells; ATP imaging; ATP release; Luciferin-luciferase bioluminescence; Mechanical stress; Mechanoporation; Membrane viscoelasticity; Purinergic signaling; Ventilation-induced lung injury; Biophysics - Medical / Biophysique - Médicale (UMI : 0760)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tan, J. J. (2021). Mechanosensitive ATP release in the lungs. (Thesis). Université de Montréal. Retrieved from http://hdl.handle.net/1866/24849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Tan, Ju Jing. “Mechanosensitive ATP release in the lungs.” 2021. Thesis, Université de Montréal. Accessed March 06, 2021. http://hdl.handle.net/1866/24849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Tan, Ju Jing. “Mechanosensitive ATP release in the lungs.” 2021. Web. 06 Mar 2021.

Vancouver:

Tan JJ. Mechanosensitive ATP release in the lungs. [Internet] [Thesis]. Université de Montréal; 2021. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1866/24849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Tan JJ. Mechanosensitive ATP release in the lungs. [Thesis]. Université de Montréal; 2021. Available from: http://hdl.handle.net/1866/24849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

15. Ouared, Abderrahmane. Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein.

Degree: 2016, Université de Montréal

URL: http://hdl.handle.net/1866/13548

Subjects/Keywords: élastographie dynamique; caractérisation tissulaire; imagerie ultrasonore; pression de radiation acoustique; onde de cisaillement; viscoélasticité; cancer du sein; modèle inverse; onde de torsion; dynamic elastography; tissue caracterization; ultrasound imaging; acoustic radiation force; shear wave; viscoelasticity; breast cancer; inverse problem; torsional shear wave; Engineering - Biomedical / Ingénierie - Biomédicale (UMI : 0541)

…Dynamic elastography, tissue characterization, ultrasound imaging, acoustic radiation force… …shear wave, viscoelasticity, breast cancer, inverse problem, torsional shear wave. vii viii… …66 2) Shear Wave Elasticity Imaging (SWEI)… …71 5) Supersonic Shear Imaging (SSI)… …Chapitre 6 : Ultrasound viscoelasticity assessment using an adaptive torsional shear wave…

11 more images…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ouared, A. (2016). Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein. (Thesis). Université de Montréal. Retrieved from http://hdl.handle.net/1866/13548

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ouared, Abderrahmane. “Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein.” 2016. Thesis, Université de Montréal. Accessed March 06, 2021. http://hdl.handle.net/1866/13548.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ouared, Abderrahmane. “Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein.” 2016. Web. 06 Mar 2021.

Vancouver:

Ouared A. Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein. [Internet] [Thesis]. Université de Montréal; 2016. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1866/13548.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ouared A. Développement d'une nouvelle méthode de caractérisation tissulaire basée sur l'élastographie ultrasonore : application pour le dépistage précoce du cancer du sein. [Thesis]. Université de Montréal; 2016. Available from: http://hdl.handle.net/1866/13548

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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Open Access Theses and Dissertations