Sökning: "functional magnetic resonance imaging"

Visar resultat 11 - 15 av 206 avhandlingar innehållade orden functional magnetic resonance imaging.

  1. 11. The architecture of the aging brain : functional reorganization, structural changes, and the role of dopamine receptors

    Författare :Robin Pedersen; Alireza Salami; Anna Rieckmann; Anders Wåhlin; Lars Nyberg; Roser Sala-Llonch; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; brain architecture; functional connectivity; dopamine; aging; cognition; memory; functional magnetic resonance imaging; positron emission tomography; graph theory; Laplacian eigenmapping; gradient;

    Sammanfattning : Aging is associated with reorganization of functional brain architecture, potentially leading tocognitive decline in older age. However, the mechanisms responsible for alterations in functionalbrain architecture remain poorly understood. LÄS MER

  3. 12. Stereotactic imaging in functional neurosurgery

    Författare :Hidehiro Hirabayashi; Patric Blomstedt; Takaomi Taira; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Deep brain stimulation; pallidotomy; thalamotomy; Parkinson s disease; essential tremor; CT; MRI; neurokirurgi; Neurosurgery;

    Sammanfattning : Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. LÄS MER

  4. 13. 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

  5. 14. Analysis and development of strategies for magnetic resonance functional neuroimaging

    Författare :Peter Fransson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :neuroimaging; human brain; functional activation; magnetic resonance imaging; cerebral blood oxygenation;

    Sammanfattning : This thesis focuses on strategies for oxygenation-sensitive MRI that are designed to measure alterations in brain physiology induced by changes in neuronal activity. In a first study, it was shown that the temporal evolution of BOLD MRI signal changes in response to both brief and sustained visual activation are equally well visible in FLASH and EPI recordings. LÄS MER

  7. 15. To select one hand while using both : neural mechanisms supporting flexible hand dominance in bimanual object manipulation

    Författare :Anna Theorin; Roland Johansson; Fredrik Ullén; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; object manipulation; bimanual coordination; action selection; cerebral cortex; functional laterality; humans; hand; magnetic resonance imaging; transcranial magnetic stimulation; electromyography; Physiology; Fysiologi; fysiologi; Physiology;

    Sammanfattning : In daily activities, the brain regularly assigns different roles to the hands dependingon task and context. Yet, little is known about the underlying neural processes. Thiscertainly applies to how the brain, where each hemisphere primarily controls onehand, manages the between-hand coordination required in bimanual objectmanipulation. LÄS MER