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Visar resultat 1 - 5 av 78 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Modern multimodal methods in brain MRI

    Författare :David Abramian; Anders Eklund; Evren Özarslan; Ida Blystad; Hamid Behjat; Jesper Andersson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MRI; Functional MRI; Diffusion MRI; Graph signal processing; Deep learning;

    Sammanfattning : Magnetic resonance imaging (MRI) is one of the pillars of modern medical imaging, providing a non-invasive means to generate 3D images of the body with high soft-tissue contrast. Furthermore, the possibilities afforded by the design of MRI sequences enable the signal to be sensitized to a multitude of physiological tissue properties, resulting in a wide variety of distinct MRI modalities for clinical and research use. LÄS MER

  3. 2. Volumetric assessment of hippocampus and cerebral white matter lesions in structural MRI

    Författare :Erik Olsson; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; structural MRI; white matter lesions; hippocampal volumetry; reliability; mild cognitive impairment; dementia; low dose radiation;

    Sammanfattning : Assessment in structural MRI like hippocampal volumetry and white matter lesion (WML) assessment is receiving widespread attention and recommen-dation as important research and diagnostic tools. The aim in this thesis is to contribute to enhanced reliability and validity in structural MRI assessment. LÄS MER

  4. 3. Structural Changes in Nonionic Surfactant Systems

    Författare :Sanja Bulut; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Vesicles; Nonionic Surfactant; Wormlike Micelles; Lamellar Phase; NMR; MRI; SLS; DLS; cryo-fracture-TEM; centrifugation; cryo-TEM;

    Sammanfattning : In this thesis we have studied structural changes of a nonionic surfactant self-assembly, as governed by changes in temperature and concentration. The techniques used in experimental investigations were dynamic and static light scattering, nuclear magnetic resonance and cryo-transmission electron microscopy (using a novel specimen preparation protocol). LÄS MER

  5. 4. Biophysical modelling in diffusion MRI: The role of tissue microstructure and water exchange

    Författare :Markus Nilsson; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Diffusion; MRI; tissue microstructure; water exchange; Monte Carlo simulations; white matter;

    Sammanfattning : Diffusion MRI is widely used to study brain structure in vivo. While this technique is often applied to investigations of brain connectivity, it can also be used to infer specific information about the tissue microstructure; for example, to estimate the axon diameter. LÄS MER

  7. 5. Neuropsychological Function in Relation to Structural and Functional Brain Changes in Alzheimer’s Disease

    Författare :Eva Elgh; Jarl Risberg; Umeå universitet; []
    Nyckelord :Alzheimer´s disease; neuropsychological function; episodic memory; hippocampus; prefrontal cortex; brain imaging; MRI; fMRI; SPECT; LHPA-axis; cortisol; geriatrik; Geriatrics;

    Sammanfattning : The aim of this doctoral thesis was to study neuropsychological function in relation to structural and functional brain changes in Alzheimer´s disease (AD). In the first study relations between hippocampal volume, neuropsychological function and limbic-hypothalamic-pituitary-adrenal (LHPA) axis disturbances in AD were investigated with magnetic resonance imaging (MRI). LÄS MER