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You searched for subject:(Cryoimaging). Showing records 1 – 3 of 3 total matches.

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University of Wisconsin – Milwaukee

1. Ghanian, Zahra. Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries.

Degree: PhD, Engineering, 2016, University of Wisconsin – Milwaukee

Optical imaging techniques have emerged as essential tools for reliable assessment of organ structure, biochemistry, and metabolic function. The recognition of metabolic markers for disease diagnosis has rekindled significant interest in the development of optical methods to measure the metabolism of the organ. The objective of my research was to employ optical imaging tools and to implement signal and image processing techniques capable of quantifying cellular metabolism for the diagnosis of diseases in human organs such as eyes and lungs. To accomplish this goal, three different tools, cryoimager, fluorescent microscope, and optical coherence tomography system were utilized to study the physiological metabolic markers and early structural changes due to injury in vitro, ex vivo, and at cryogenic temperatures. Cryogenic studies of eye injuries in animal models were performed using a fluorescence cryoimager to monitor two endogenous mitochondrial fluorophores, NADH (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide). The mitochondrial redox ratio (NADH/ FAD), which is correlated with oxidative stress level, is an optical biomarker. The spatial distribution of mitochondrial redox ratio in injured eyes with different durations of the disease was delineated. This spatiotemporal information was helpful to investigate the heterogeneity of the ocular oxidative stress in the eyes during diseases and its association with retinopathy. To study the metabolism of the eye tissue, the retinal layer was targeted, which required high resolution imaging of the eye as well as developing a segmentation algorithm to quantitatively monitor and measure the metabolic redox state of the retina. To achieve a high signal to noise ratio in fluorescence image acquisition, the imaging was performed at cryogenic temperatures, which increased the quantum yield of the intrinsic fluorophores. Microscopy studies of cells were accomplished by using an inverted fluorescence microscope. Fixed slides of the retina tissue as well as exogenous fluorophores in live lung cells were imaged using fluorescent and time-lapse microscopy. Image processing techniques were developed to quantify subtle changes in the morphological parameters of the retinal vasculature network for the early detection of the injury. This implemented image cytometry tool was capable of segmenting vascular cells, and calculating vasculature features including: area, caliber, branch points, fractal dimension, and acellular capillaries, and classifying the healthy and injured retinas. Using time-lapse microscopy, the dynamics of cellular ROS (Reactive Oxygen Species) concentration was quantified and modeled in ROS-mediated lung injuries. A new methodology and an experimental protocol were designed to quantify changes of oxidative stress in different stress conditions and to localize the site of ROS in an uncoupled state of pulmonary artery endothelial cells (PAECs). Ex vivo studies of lung were conducted using a spectral-domain optical… Advisors/Committee Members: Mahsa Ranji.

Subjects/Keywords: Disease Diagnosis; Fluorescence Microscopy; Image Analysis; Optical Coherence Tomography; Optical Cryoimaging; Oxidative Stress; Bioimaging and Biomedical Optics; Biomedical Engineering and Bioengineering; Optics

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

APA (6th Edition):

Ghanian, Z. (2016). Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries. (Doctoral Dissertation). University of Wisconsin – Milwaukee. Retrieved from https://dc.uwm.edu/etd/1368

Chicago Manual of Style (16th Edition):

Ghanian, Zahra. “Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries.” 2016. Doctoral Dissertation, University of Wisconsin – Milwaukee. Accessed December 08, 2019. https://dc.uwm.edu/etd/1368.

MLA Handbook (7th Edition):

Ghanian, Zahra. “Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries.” 2016. Web. 08 Dec 2019.

Vancouver:

Ghanian Z. Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries. [Internet] [Doctoral dissertation]. University of Wisconsin – Milwaukee; 2016. [cited 2019 Dec 08]. Available from: https://dc.uwm.edu/etd/1368.

Council of Science Editors:

Ghanian Z. Quantitative Optical Studies of Oxidative Stress in Rodent Models of Eye and Lung Injuries. [Doctoral Dissertation]. University of Wisconsin – Milwaukee; 2016. Available from: https://dc.uwm.edu/etd/1368


Case Western Reserve University

2. Salvado, Olivier. CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION.

Degree: PhD, Biomedical Engineering, 2006, Case Western Reserve University

The long-term goal of this research is the characterization of atherosclerosis lesions in vivo using Magnetic Resonance Imaging (MRI). Our particular interest is the computer-aided diagnosis and staging of the disease, especially the detection of vulnerable plaques. Multi-contrast MRI scans are used (e.g. PDW, T1W, and T2W) to assess the presence and morphology of vessel lesions in human arteries. The first chapter of this thesis reviews the existing techniques for atherosclerosis imaging with emphasis on MRI. The challenges facing intensity-based computer methods are then investigated. The subsequent four chapters address specifically the four main issues that have been identified: 1) Intensity inhomogeneity, which is present when surface coils or intravascular microcoils induce shading artifacts across the data. Artifacts are modeled as a smooth multiplicative bias field with a cubic spline. The cubic spline is optimized to minimize the entropy of the corrected image. Extension to intravascular axial images is presented. 2) Partial volume effect; despite recent improvements in MRI technologies, image resolution is still a limiting factor owing to the small size of the vessel wall and its lesions. A new approach is investigated to address this issue. Under the assumption that homogenous tissues are well separated by an edge, a reverse diffusion model is implemented. Extension to reduce noise is also introduced by using a diffusion coefficient function of the image gradient. 3) Misregistration; Patient and physiological motions induce misregistration between the datasets with different contrast, requiring methods with sub-voxel accuracy to re-align them. The limits of registration methods are investigated and a new constant variance filter is described to improve intensity-based automatic registration accuracy and robustness. This filter removes local maxima and global bias in similarity measures. 4) The last issue investigated is validation; a new method is presented to produce three-dimensional ground truth of ex vivo vessel specimens. This method uses a novel Cryoimaging system where frozen specimens are serially cut and imaged using bright field and fluorescence microscopy. The last chapter discusses potential applications to other diseases and image modalities, future works, and concludes about the perspectives of atherosclerosis imaging with MRI. Advisors/Committee Members: Wilson, David (Advisor).

Subjects/Keywords: Engineering, Biomedical; Atheroclerosis; Magnetic Resonance Imaging; Intensity inhomegeneity; Partial volume effect; Noise; Anisotropic diffusion; Vulnerable plaque; Cryoimaging; Segmetnation; Tissue classification; Registration

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

APA (6th Edition):

Salvado, O. (2006). CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION. (Doctoral Dissertation). Case Western Reserve University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=case1152214735

Chicago Manual of Style (16th Edition):

Salvado, Olivier. “CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION.” 2006. Doctoral Dissertation, Case Western Reserve University. Accessed December 08, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1152214735.

MLA Handbook (7th Edition):

Salvado, Olivier. “CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION.” 2006. Web. 08 Dec 2019.

Vancouver:

Salvado O. CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION. [Internet] [Doctoral dissertation]. Case Western Reserve University; 2006. [cited 2019 Dec 08]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1152214735.

Council of Science Editors:

Salvado O. CHARACTERIZATION OF ATHEROSCLEROSIS WITH MAGNETIC RESONANCE IMAGING, CHALLENGES AND VALIDATION. [Doctoral Dissertation]. Case Western Reserve University; 2006. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1152214735

3. Maleki, Sepideh. Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice.

Degree: MS, Engineering, 2012, University of Wisconsin – Milwaukee

Diabetic Nephropathy (DN) is the major single cause of end stage renal diseases (ESRD) in the United States. Diabetes is the third leading fatal disorder after cancer and heart disease. It is affecting 8.3% of the residents of the United States, with a total healthcare cost of $174 billion/yr by 2010. There currently exists a need for a sensitive and specific diagnosis for temporal detection of oxidative stress (OS) in cellular metabolic levels, which plays an early role in the development of DN. The objective of this research is to use a fluorescence optical imaging technique in order to delineate temporal and spatial distribution of OS and to evaluate mitochondrial redox state in rodents kidney tissue during diabetes progression. In this research, I investigated whether changes in the metabolic state can be used as a quantitative marker of OS progression in kidneys. Through the monitoring of autofluorescent mitochondrial metabolic coenzymes (NADH, FAD), the redox state of mitochondria can be probed in many intact organs. I have applied a device called cryoimager to measure the fluorescence intensity of these fluorophores simultaneously in 3-D. The ratio of these fluorophores, referred to as the NADH redox ratio (RR), can be used as a quantitative metabolic marker of tissue. I examined redox states of kidneys from diabetic mice, Akita/+, Akita/+; TSP1-/- (Akita mice lacking thrombospondin-1, TSP1) with increasing duration of diabetes, and kidneys from bcl-2-deficient mice. We detected OS shortly after the onset of diabetes by NADH RR, which increased during progression of diabetes. RR indicates a more reduced biochemical state in kidneys from diabetic mice compared with kidneys from wilde type (control) mice. Thus, cryo fluorescence redox imaging showed a quantitative marker of OS progression in kidneys from diabetic mice and demonstrated that alterations in the oxidative state of kidneys occur at different stages of diabetes. Advisors/Committee Members: Mahsa Ranji.

Subjects/Keywords: Cellular Redox; Cryoimaging; Diabetes; Kidney; Mitochondria; Oxidative Stress; Biomedical Engineering and Bioengineering; Electrical and Electronics; Optics

…Chapter 2 Optical Cryoimaging of Diabetic Nephropathy 24 2. Cryoimaging 2.1. Introduction… …45mm. Further details of each design can be found in the following section. Cryoimaging is… 

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

APA (6th Edition):

Maleki, S. (2012). Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice. (Thesis). University of Wisconsin – Milwaukee. Retrieved from https://dc.uwm.edu/etd/20

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

Chicago Manual of Style (16th Edition):

Maleki, Sepideh. “Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice.” 2012. Thesis, University of Wisconsin – Milwaukee. Accessed December 08, 2019. https://dc.uwm.edu/etd/20.

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

MLA Handbook (7th Edition):

Maleki, Sepideh. “Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice.” 2012. Web. 08 Dec 2019.

Vancouver:

Maleki S. Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice. [Internet] [Thesis]. University of Wisconsin – Milwaukee; 2012. [cited 2019 Dec 08]. Available from: https://dc.uwm.edu/etd/20.

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

Council of Science Editors:

Maleki S. Optical Cryoimaging of Celular Redox in Kidneys from Diabetic Mice. [Thesis]. University of Wisconsin – Milwaukee; 2012. Available from: https://dc.uwm.edu/etd/20

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

.