Sökning: "medicinsk instrumentering"
Visar resultat 1 - 5 av 57 avhandlingar innehållade orden medicinsk instrumentering.
1. 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
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
2. Evaluation of Automatic Quantification Programs for Myocardial Perfusion SPECT using Monte Carlo Simulations
Sammanfattning : Coronary artery disease (CAD) is a condition in which the blood supply to the myocardium is partially or completely blocked due to plaque build-up in the artery wall. Myocardial SPECT imaging is a commonly used technique to assess the blood flow to the myocardium and the function of the heart. LÄS MER
3. Development and evaluation of an independent system for absorbed dose calculations in radiotherapy
Sammanfattning : The aim of this work was to develop, implement and evaluate an independent system with which to calculate the absorbed dose, delivered by high-energy X-ray beams, to the prescription point and the depth of dose maximum. The introduction of such a system in the clinical routine may help ensure high-quality treatment and avoidance of errors which may jeopardise the clinical outcome of the treatment (i. LÄS MER
Sammanfattning : Radionuclide therapy requires patient-specific planning of the absorbed dose to target volumes, in most cases tumours, in order to achieve an expected biological effect, taking into account that the absorbed doses to normal organs and tissues should be kept as low as reasonably achievable. Therefore, the calculation of absorbed doses has to be as accurate as possible. LÄS MER
Sammanfattning : The studies presented in this thesis concern the optimisation and evaluation of the dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) technique for the assessment of perfusion-related parameters of the brain, such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT). Several methodological factors influence these measurements, for example, contrast-agent administration, arterial input function (AIF) registration, choice of deconvolution algorithm and the choice of pulse-sequence parameters. LÄS MER