Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"Diffusion Magnetic Resonance Imaging"”.
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Cerebral white matter analysis using diffusion imaging
… whole-brain tractography segmentation problem. Diffusion magnetic resonance imaging can be used to create a representation of white matter tracts in the brain via a process called tractography. Whole brain tractography outputs thousands of trajectories that each approximate a white matter fiber …
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Validation of dMRI techniques for mapping brain pathways
Diffusion magnetic resonance imaging (dMRI) tractography is the only non-invasive tool for studying the connectional architecture of the brain in vivo. By measuring the diffusion of water molecules dMRI provides unique information about white matter pathways and their integrity, making it an …
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Examining the Association between Brain MRI Measures at 7 Tesla and cognition following COVID-19 Infection
… COVID-19 illness and determined whether advanced diffusion magnetic resonance imaging measures within subcortical brain structures of the limbic system were related to neurological, respiratory, psychiatric, and gastric symptoms experienced during the acute phase of illness. Cognitive and …
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Rank constrained denoising in magnetic resonance imaging
Noise is an important issue in magnetic resonance imaging (MRI), since the signal-to-noise ratio (SNR) is a major limiting factor for imaging speed and the achievable spatial resolution. This thesis investigates the utility of low-rank property in the denoising problem for the following two MRI …
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Advanced Methods for Diffusion MRI Data Analysis and their Application to the Healthy Ageing Brain
Diffusion of water molecules in biological tissues depends on several microstructural properties. Therefore, diffusion Magnetic Resonance Imaging (dMRI) is a useful tool to infer and study microstructural brain changes in the context of human development, ageing and neuropathology. In this thesis, …
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Validation of MRtrix tractography for clinical use
… is a technique which uses non-invasive diffusion magnetic resonance imaging (dMRI) to model the structural connections of the brain in vivo. Since it is not known to what extent the exact positions of white matter tracts vary between individuals, and how scan parameters affect the …
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Exploring Tissue Microstructure in Healthy and Diseased Lung Tissue
… divided into two parts. The first part examines diffusion in a number of human lung samples, while the second deals with diffusion in the more simplified environment of a single capillary tube. In the lung study we examine various types of lung samples: healthy and diseased) at a variety of …
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Applied Sampling and Reconstruction of Signals on the Sphere
… various disciplines, such as geophysics, medical imaging, computer graphics, wireless communications and acoustics. This thesis focuses on the development of signal processing techniques for sampling and reconstruction of signals on the sphere. The objective of developing new spherical signal …
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Applied Sampling and Reconstruction of Signals on the Sphere
… various disciplines, such as geophysics, medical imaging, computer graphics, wireless communications and acoustics. This thesis focuses on the development of signal processing techniques for sampling and reconstruction of signals on the sphere. The objective of developing new spherical signal …
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Novel Chemically Selective Rapid Magnetic Resonance Imaging Techniques and the Clinical Applications
Magnetic Resonance Imaging (MRI) has become as powerful, non-invasive imaging modality for both diagnostic and research purposes. Nevertheless, the efficacy and efficiency of MRI can still be improved by the development of novel imaging methods (pulse sequences), as well as by exploring the …
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Correspondence among connectomes as combinatorial optimization
Diffusion magnetic resonance imaging (dMRI) data allows the reconstruction of the neural pathways of the white matter of the brain as a set of 3D polylines, by means of tractography algorithms. The neuronal axons within the white matter form the anatomical links between regions of the brain, which …
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MRI at 3 T of brain functions and fibre tracts adjacent to intracranial tumors
… (Paper 3); to determine whether the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) can distinguish tumor-infiltrated edema of gliomas from pure edema of meningiomas and metastases (Paper 4). Results: Strict somatotopic organisation in the primary sensory cortex was shown …