MR applications at CRICBristol
Full body MR imaging and spectroscopy
Arterial Spin Labelling (ASL) can be sensitised to the effect of inflowing blood spins if those spins are in a different magnetic state to that of static tissue. Techniques known as ASL techniques uses this idea by magnetically labelling blood flowing into the slices of interest. Contrast agents are not required for these techniques.
Functional MRI measures signal changes in the brain that are due to changing neural activity. The brain is scanned at low resolution but at a rapid rate (typically once every two to three seconds). Increases in neural activity cause changes in the MR signal via T2* changes this mechanism is referred to as the BOLD (blood-oxygen-level dependent) effect.
MR Spectroscopy is used to measure the levels of different metabolites in body tissues. The MR signal produces a spectrum of resonances that correspond to different molecular arrangements of the isotope being ''excited''. This signature is used to diagnose certain metabolic disorders, especially those affecting the brain.
Perfusion is defined as the passage of fluid through the lymphatic system or blood vessels to an organ or a tissue. The practice of perfusion scanning is the process by which this profusion can be observed, recorded and quantified.
Contrast Enhanced MRI uses a contrast media to improve the visibility of internal body structures in MRI. MRI contrast agents alter the relaxation times of tissues and body cavities where they are present. Depending on the image weighting, this can give a higher or lower signal.
Diffusion Tensor (DTI) Diffusion weighted (DWI) imaging is a method that produces in vivo images of biological tissues weighted with the local microstructural characteristics of water diffusion. There are two distinct classes of application. DWI can provide information about damage to parts of the nervous system. DTI can provide information about connections among brain regions.
Facilities for data analysis and high performance computing are available.