Sökning: "nuclear magnetic resonance"

Visar resultat 1 - 5 av 327 avhandlingar innehållade orden nuclear magnetic resonance.

  1. 1. Positron Emission Tomography and Magnetic Resonance Techniques in Diabetes

    Författare :Lina Carlbom; Håkan Ahlström; Olle Korsgren; Olof Eriksson; Lars Johansson; Tove Grönroos; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron emission tomography; Magnetic resonance imaging; Magnetic resonance spectroscopy; Type 1 diabetes; Type 2 diabetes; PET MR; Pancreas transplantation; Perfusion; Radiology; Radiologi;

    Sammanfattning : In order to further advance the field of diabetes research there is a great need for establishing validated non-invasive quantitative techniques to study the pancreas and other tissues of importance for blood glucose regulation. The general aim of this thesis was to explore magnetic resonance techniques and positron emission tomography as such tools. LÄS MER

  2. 2. Quality assurance for magnetic resonance imaging (MRI) in radiotherapy

    Författare :Mary Adjeiwaah; Tufve Nyholm; Anders Garpebring; Joakim Jonsson; Sofie Ceberg; Umeå universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; magnetic resonance imaging; MRI; radiotherapy; RT; geometric distortions; magnetic susceptibility; B0 maps; quality assurance; radiofysik; radiation physics;

    Sammanfattning : The use of Magnetic Resonance Imaging (MRI) in the radiotherapy (RT) treatment planning workflow is increasing. MRI offers superior soft-tissue contrast compared to Computed Tomography (CT) and therefore improves the accuracy in target volume definitions. LÄS MER

  3. 3. Heterogeneous Materials - Diffusion, Laplace Spectrum, and Nuclear Magnetic Resonance

    Författare :Matias Nordin; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; eigenfunctions; eigenvalues; propagator; diffusion; Laplace operator; Nuclear Magnetic Resonance;

    Sammanfattning : In this thesis diffusion in heterogeneous materials is studied using spectral analysisof the Laplace operator. Relations to the effective diffusion constant and therelaxation rate of the time-dependent diffusion coefficient for porous systems arederived from the Laplace operator’s spectrum. LÄS MER

  4. 4. Proton Magnetic Resonance Spectroscopy in Brain Tumors - Clinical Applications

    Författare :Isabella Björkman-Burtscher; Lund Diagnostisk radiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiology; Clinical physics; Localization; Abscess; Brain; Tumor; Spectroscopy; Magnetic Resonance; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

    Sammanfattning : Aims: · to present a test phantom and test method for evaluation of proton magnetic resonance spectroscopy (1H-MRS) single volume localization techniques regarding signal contamination; · to describe the introduction of 1H-MRS in the daily routine of a standard MR-unit; · to evaluate the possibilities offered by 1H-MRS to improve preoperative diagnostic accuracy in patients scheduled for stereotactic biopsy of intracranial mass lesions; · to evaluate the possibilities offered by 1H-MRS to improve diagnostics and therapy control in patients with brain abscesses; · to test the hypothesis that 1H-MRS might be useful for differentiation of brain tumors, based on metabolic changes in tissue across brain lesions or surrounding tissue. Results and conclusions: · The test phantom and test method allow quality assessment with good reproducibility. LÄS MER

  5. 5. Non-Invasive Characterization of Liver Disease : By Multimodal Quantitative Magnetic Resonance

    Författare :Markus Karlsson; Peter Lundberg; Gunnar Cedersund; Nils Dahlström; Stergios Kechagias; Steven Sourbron; Linköpings universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

    Sammanfattning : There is a large and unmet need for diagnostic tool that can be used to characterize chronic liver diseases (CLD). In the earlier stages of CLD, much of the diagnostics involves performing biopsies, which are evaluated by a histopathologist for the presence of e.g. fat, iron, inflammation, and fibrosis. LÄS MER