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 16 of 16 for “"dMRI"”.
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Machine Learning for Tract Segmentation in dMRI data
Diffusion MRI (dMRI) data allows to reconstruct the 3D pathways of axons within the white matter of the brain as a set of streamlines, called tractography. A streamline is a vectorial representation of thousands of neuronal axons expressing structural connectivity. An important task is to group the …
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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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MRI for gray matter: statistical modelling for in-vivo application and histological validation of dMRI
… (e.g., structural MRI (sMRI) and diffusion MRI (dMRI)) provide a unique opportunity to non-invasively study GM structure in-vivo and thus can be used to probe GM pathology in development, aging and neuropsychiatric disorders. Investigation of the influence of various factors on MRI measures in GM …
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Diffusion-weighted MRI of skeletal muscle: Estimation of microstructural parameters
… Diffusion-weighted magnetic resonance imaging (dMRI) enables the non-invasive probing of the microstructural organization of tissue by sensitizing the MR signal to the micron length scale displacements of water molecules within the tissue, which then probe the geometrical features of the …
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The Rat as a Translational Model of Neurotrauma: Primary Somatosensory Input and Imaging Biomarker Validation Following Spinal Cord and Peripheral Nerve Injuries
… clinical tools are limited. Diffusion MRI (dMRI) has the potential to classify nerve injury severity and evaluate nerve recovery more accurately and earlier in time than current electrodiagnostics but requires validation. In this study, we evaluated the rat’s suitability as a translation …
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Advanced Methods for Diffusion MRI Data Analysis and their Application to the Healthy Ageing Brain
… 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, the state-of-the-art of advanced dMRI techniques is explored and strategies to overcome or reduce …
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Desenvolvimento de um sistema embarcado para auxílio no diagnóstico e acompanhamento de degeneração macular relacionada a idade utilizando imagens da retina
Degeneração macular relacionada à idade (DMRI) é uma doença degenerativa que atinge a região da mácula ocular e é apontada como uma das principais causadoras da perda de visão entre indivíduos com mais de 50 anos em países não desenvolvidos. A presença de depósitos celulares de cor amarelada …
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Applied Sampling and Reconstruction of Signals on the Sphere
… signal in diffusion magnetic resonance imaging (dMRI). In contrast to existing sampling schemes in the literature, the developed schemes attain the optimal number of samples, equal to the degrees of freedom in spherical harmonic space, while enabling computation of the spherical harmonic …
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Applied Sampling and Reconstruction of Signals on the Sphere
… signal in diffusion magnetic resonance imaging (dMRI). In contrast to existing sampling schemes in the literature, the developed schemes attain the optimal number of samples, equal to the degrees of freedom in spherical harmonic space, while enabling computation of the spherical harmonic …
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Validation of MRtrix tractography for clinical use
… 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 reconstructed location of tracts, the …
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Deep Learning for Brain Structural Connectivity Analysis: From Tissue Segmentation to Tractogram Alignment
… with advanced sequences such as diffusion MRI (dMRI) for the computation of the structural connectivity of the brain. In particular, from the processing of dMRI data, it is possible to investigate the structures of WM through tractography techniques, obtaining a virtual representation of the WM …
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Using open-source data repository initiatives to investigate impaired white matter connectivity in autism
… biomarkers. For Experiment I, we aggregated dMRI scans from open-sourced data sharing initiatives to investigate the degree to which WM diffusion is abnormal in autism compared to age-matched neurotypical controls (NT). dMRI data was acquired from the ABIDE II repository, Carnegie Mellon …
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White matter connectivity, cognition, symptoms and genetic risk factors in Schizophrenia
… in schizophrenia using diffusion MRI (dMRI) data. Our first aim was to examine whether processing speed mediated the association between white matter structure and general intelligence in patients diagnosed with schizophrenia in the SFMH study. Secondly, we investigated specific …
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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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The Neurocognitive Sequelae of Chronic Traumatic Brain Injury and the Utility of Treatment with Methylphenidate
Traumatic Brain Injury (TBI) is a serious world-wide public health concern with a pressing need for adequate, effective long-term treatment. Cognitive deficits are a common complaint after TBI and persistent disabilities endure well into the chronic phases of the injury. Few recognised standard …