Sökning: "X-ray Computed Tomography"

Visar resultat 21 - 25 av 122 avhandlingar innehållade orden X-ray Computed Tomography.

  1. 21. Magnetic resonance imaging with ultrashort echo time as a substitute for X-ray computed tomography

    Författare :Adam Johansson; Tufve Nyholm; Karlsson Mikael; James Balter; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic resonance imaging; computed tomography substitute; ultrashort echo time; parallel imaging; radial imaging; radiofysik; radiation physics;

    Sammanfattning : Radiotherapy dose calculations have evolved from simple factor based methods performed with pen and paper, into computationally intensive simulations based on Monte Carlo theory and energy deposition kernel convolution.Similarly, in the field of positron emission tomography (PET), attenuation correction, which was originally omitted entirely, is now a crucial component of any PET reconstruction algorithm. LÄS MER

  3. 22. Long-term health hazards from diagnostic X-ray exposure

    Författare :Arvid Nordenskjöld; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Medical imaging is an important function in the diagnosis and management of disease and its use have been increasing with technological advancements. A large part of medical imaging uses ionizing radiation as medium for imaging although it does pose potential risks to the patient. LÄS MER

  4. 23. Synthesis and Characterization of Nanoprobes for X-Ray Fluorescence Computed Tomography (XFCT) Bio-imaging

    Författare :Yuyang Li; Muhammet Toprak; Hans Hertz; Ender Suvaci; KTH; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : X-ray fluorescence computed tomography (XFCT) is an emerging biomedical imaging technique. The KTH-XFCT laboratory system offers a characteristic 24 keV emission line, and high spatial resolution (200 ?m) images. XFCT as a newly emerging modality also requires the exploration and development of suitable contrast agents. LÄS MER

  5. 24. Reducing Atelectasis during General Anaesthesia – the Importance of Oxygen Concentration, End-Expiratory Pressure and Patient Factors : A Clinical Study Exploring the Prevention of Atelectasis in Adults

    Författare :Lennart Edmark; Mats Enlund; Göran Hedenstierna; Sten Lindahl; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Anaesthesia; general. Lung: Atelectasis; CPAP; Oxygen; PEEP; Ventilation; mechanical; Tomography; X-ray computed.; Anestesiologi; Anaesthesiology; Fysiologi; Physiology;

    Sammanfattning : Background: The use of pure oxygen during preoxygenation and induction of general anaesthesia is a major cause of atelectasis. The interaction between reduced lung volume, resulting in airway closure, and varying inspiratory fractions of oxygen (FIO2) in determining the risk of developing atelectasis is still obscure. LÄS MER

  7. 25. Computed Tomography and Magnetic Resonance Imaging in Determination of Human Body Composition. Methodological and Applied Studies

    Författare :John Brandberg; Göteborgs universitet; []
    Nyckelord :X-ray Computed Tomography; Magnetic Resonance Imaging; Body Composition; Obesity; Metabolic Syndrome X; Glucose Metabolism; Growth Hormone; Fatty Liver; Intra-Abdominal Fat;

    Sammanfattning : Background: Computed tomography (CT) and magnetic resonance imaging (MRI) provide important research opportunities due to their unique capability of characterizing and quantifying tissues and organs. Ionizing radiation is a limitation using CT, and recent developments aiming to improve MRI for determination of body composition have not been validated. LÄS MER