Avancerad sökning

Hittade 3 avhandlingar som matchar ovanstående sökkriterier.

1. 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

   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

3. 2. Contributions to quantitative dynamic contrast-enhanced MRI

   Författare :Anders Garpebring; Mikael Karlsson; Ronnie Wirestam; Nils Östlund; Jón Hauksson; Steven Sourbron; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic contrast-enhanced MRI; quantitative imaging; parameter estimation; uncertainty estimation; arterial input function; radiofysik; radiation physics;

   Sammanfattning : Background: Dynamic contrast-enhanced MRI (DCE-MRI) has the potential to produce images of physiological quantities such as blood flow, blood vessel volume fraction, and blood vessel permeability. Such information is highly valuable, e.g., in oncology. LÄS MER

4. 3. 4D flow MRI and modelling to assess cerebral arterial hemodynamics : method development and evaluation, with implementation in patients with symptomatic carotid stenosis

   Författare :Madelene Holmgren; Anders Eklund; Jan Malm; Anders Wåhlin; Sara Qvarlander; Ronnie Wirestam; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; 4D flow MRI; carotid stenosis; cerebral blood flow; cerebral arterial compliance; cerebrovascular resistance; circleof Willis; computational fluid dynamics; magnetic resonance imaging; stroke; vascular disease; Neurology; neurologi;

   Sammanfattning : Blood flow measurements are important for understanding the development of cerebrovascular diseases. With 4D flow magnetic resonance imaging (4D flow MRI), simultaneous velocity measurements are obtained in all cerebral arteries in a scan of about ten minutes. However, 4D flow MRI is a relatively new technique. LÄS MER