Progressive supranuclear palsy (PSP) is a neurodegenerative disease affecting multiple neural systems, particularly the extrapyramidal system. Early differentiation of PSP from other diseases mainly featuring parkinsonism, such as Parkinson's disease and multiple system atrophy, is necessary because the therapeutic strategy and outcome are substantially different. Diffusion tensor imaging is a recently developed magnetic resonance imaging (MRI) sequence that is able to non-invasively evaluate neural tracts. Two approaches may be used to measure diffusion properties. One approach is to measure diffusion properties by setting the regions of interest on circular/square regions or along the tractography. The other approach is to perform voxel-by-voxel analysis of the diffusion properties. There are several reports evaluating diffusion tensor abnormalities in PSP, and regions with diffusion tensor abnormlities are distributed through frontal projection fibres, the anterior part of the corpus callosum, superior longitudinal fasciculus, arcuate fasciculus, posterior thalamic radiations, internal capsule and superior cerebellar peduncles. Here, diffusion tensor studies in PSP are reviewed and clinical applications, limitations and future perspectives of diffusion tensor analysis in PSP are discussed.
Migration energy barriers and diffusion anisotropy of point defects on tungsten surfaces
