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Magnetic resonance imaging (MRI or also Nuclear Magnetic Resonance [NMR]) is a modern neuroimaging technique that acquires high-resolution structural images of body parts and functional measurements of physiological processes. Images can be obtained in different planes and are used to gain detailed informations about the brain, the cranial bones, the spine and spinal discs, the spinal cord and peripheral nerves. High contrast images can be taken from softer tissue like the brain and inner organs. Here, details as small as one millimeter are visible.
Up to now, the Siemens Magnetom Trio system is one of the most modern 3.0 Tesla MRIs. It is equipped with a gradient-strength of 45mT/m (minimal slew rate of 200mT/m/s) and more than 32 high-frequency channels and the Tim technology. Besides its application in common structural and functional neuroimaging, the system enables diffusion-weighted tractography, which is especially important for the planning and preparation of surgery. For further examples of of system application fields see the section ‘Methods and Expertise of research infrastructure’.
To gain information about functional processes in the brain, the MRI takes advantage of the fact that active brain regions must be provided with oxygen via bloodflow. Oxygen is provided to neurons by haemoglobin which changes its magnetic characteristics depending on the degree of oxygenation. During passive stimulation (visual, acoustic or sensory) or during active instructions to the participant (movements or performance on mental tasks), neural activity in involved brain region leads to increased blood oxygenation. This form if MRI is known as blood oxygenation level dependent (BOLD) imaging.
Subsequent data processing is then able to reveal insights in regions that become active during specific tasks.
Dr. Martin Kronbichler
Functional imaging during the performance of various tasks like visual word recognition, reading, visual object recognition and theory of mind (thoughts about the mental states of other persons)
Examination of various participants with specific characteristics such as dyslexia, patients in a persistent vegetative state, consciousness disorders, psychological and neurological disorders (schizophrenia, pathological gambling, anorexia nervosa, etc.), comparison of age groups (acquisition of reading in children, cognitive performance in the advanced age, etc.)
Analyses of advertising-effectiveness with regard to the activation differences in audible / visual advertising
The combination of magnetic resonance tomography with other methods, including electroencephalography, transcranial magnetic stimulation, transcranial DC stimulation, eye movement measurements and hormonal analyze.
Pre-surgical examinations of patients by means of structural and functional imaging.
Methods & Expertise for Research Infrastructure
The Siemens Magnetom Trio 3 Tesla device is used to perform functional and structural MRI examinations with psychological or neurocognitive aims. For example, it examines which brain areas become active in certain tasks (e.g., reading, judging image material) to draw conclusions about the underlying cognitive processes. The magnetic resonance tomograph provides a flexible spatial range, reaching from small measuring fields (e.g. within the brain) to whole-body images.
A special method in magnetic resonance tomography makes it possible to measure diffusion movements of water molecules in the body or brain tissue. This Diffusion tensor imaging (DTI) is a non-invasive method that allows conclusions about the microstructural characteristics of the brain. DTI can be used to evaluate changes in the diffusion of water molecules into the white substance of the human brain (e.g. caused through training).
Further fields of application are arterial spin-labeling, perfusion-MRI, etc.
Allocation to Core Facility
Linguistic Department, University of Salzburg
Christian Doppler Klinik, Salzburg
Jubiläumsfonds of the National Bank of Austria
Network analysis of functional connectivity in patients with a disorder of consciousness using functional neuroimaging
Scientific Funds of the Paracelsus Private Medical University
Examining voluntary brain activation in patients with disorders of consciousness
Dyslexia: Longitudinal Study of Brain Dysfunctions
FWF – Austrian Science Fund
Neural correlates of thinking about other minds in schizophrenia: Hypo or hypermentalizing?
Scientific Funds of the Paracelsus Medical University