Sökning: "nuclear magnetic resonance"

Visar resultat 16 - 20 av 404 avhandlingar innehållade orden nuclear magnetic resonance.

  1. 16. Nuclear Magnetic Resonance for Diffusion Imaging Development and evaluation of spin-echo-based pulse sequences for in vivo studies of water self-diffusion

    Författare :Sara Brockstedt; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; perfusion fraction; electrocardiographic triggering; segmented EPI SEPI ; echo-planar imaging EPI ; fast spin-echo FSE ; spin-echo SE ; navigator echoes; phase corrections; diffusion; Magnetic resonance; MRI; ischaemic stroke; Medicine human and vertebrates ; Medicin människa och djur ;

    Sammanfattning : The interest in diffusion imaging with nuclear magnetic resonance techniques has increased during the last few years. The main reason is the possibility of early diagnosis of acute ischaemic stroke, at a time when conventional MR techniques and computerised tomography fail. LÄS MER

  3. 17. Paramagnetic relaxation reagents : nuclear magnetic resonance studies of preferential solvation

    Författare :Hans Grahn; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The interactions between neutral paramagnetic relaxation reagents (PARR's) and certain aromatic compounds have been studied by 1H and 13 C spin-lattice relaxation time measurements. In media such as cyclohexane and carbon tetrachloride, Cr(acac)3 becomes preferentially solvated by aromatic solutes. LÄS MER

  4. 18. Polycystic ovary syndrome - morphologic and dynamic evaluation by magnetic resonance imaging

    Författare :Henrik Leonhardt; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; polycystic ovary syndrome; PCOS; magnetic resonance imaging; MRI; ultrasonography; three-dimensional imaging; adrenal hyperplasia; body composition; uterine morphology; uterine peristalsis; ovarian morphology; ovarian perfusion; antral follicle count; AMH; diagnostic accuracy;

    Sammanfattning : Polycystic ovary syndrome (PCOS) is a complex endocrine disorder, affecting up to 15% of women of reproductive age. The syndrome is characterized by oligo-anovulation, hyperandrogenism and polycystic ovaries. What constitutes the best definition of PCOS is still a matter of debate. LÄS MER

  5. 19. Nuclear magnetic resonance and microcirculation: The influence of pulsatile brain-tissue motion on measurements of intravoxel incoherent motion and assessment of haemodynamics using exo- and endogenous tracers

    Författare :Ronnie Wirestam; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; diagnostic radiology; cortical activation; diffusion; tumor; tumour; ischemic stroke; ischaemic stroke; tracer kinetics; bolus tracking; phase mapping; brain motion; intracranial dynamics; blood flow; haemodynamics; vascularity; MRS; perfusion; MRI; magnetic resonance; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

    Sammanfattning : In this project, the potential of magnetic resonance (MR) imaging and spectroscopy in studies of microcirculation and haemodynamics was evaluated. The spatial and temporal characteristics of human pulsatile brain-tissue movements in healthy individuals, relevant for the understanding of the cerebrospinal-fluid (CSF) circulation and the pathogenesis of hydrocephalus, were thoroughly investigated. LÄS MER

  7. 20. Degradation, Metabolism and Relaxation Properties of Iron Oxide Particles for Magnetic Resonance Imaging

    Författare :Karen Briley Saebo; Håkan Ahlström; Atle Bjørnerud; Michael Knopp; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiology; Magnetic Resonance Imaging; contrast agents; iron oxide particles; metabolism; relaxation mechanisms; Radiologisk forskning; Radiological research; Radiologisk forskning;

    Sammanfattning : Whereas the effect of size and coating material on the pharmacokinetics and biodistribution of iron oxide based contrast agents are well documented, the effect of these parameters on liver metabolism has never been investigated. The primary purpose of this work was to evaluate the effect of iron oxide particle size and coating on the rate of liver clearance and particle degradation using a rat model. LÄS MER