Meeting Banner
Abstract #0982

The Diffusion Ellipsoid Loses Planarity in Early Alzheimers Disease

Julio Acosta-Cabronero1, Stephanie Alley2, Guy B. Williams3, Peter J. Nestor1

1Department of Clinical Neurosciences, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 3Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

In early-stage clinical Alzheimers disease, the most prominent alterations measured by diffusion tensor imaging are characterised by the apparent increase in both axial and transverse self-diffusion components. This tensor behaviour, however, causes fractional anisotropy to grossly underestimate the true extent of early abnormalities. In this study, we explored a wide range of anisotropy metrics, and found that white matter changes in mild Alzheimers disease are best described by the loss of tensor planarity.

Abstract PDF

Keywords

abnormalities abnormally abruptly absolute abstract addition agreement alterations anisotropic anisotropy appeared appears applied axial axially better brain called capable clinical closer cluster cohort coil coils common components compute computed concert concordant connecting context contrast controls corrected degrees derived detect detection diffusion diffusivity disease disproportionate dissect diverges earlier early eddy effective eigenvalues eigenvectors ellipsoid examination expands explored extensive family features former fractional gain geometric gradients hence highlighted highly identify impaired kingdom lancet linear loses loss maps mathematics meaningful measured measures mental metric metrics mild much note noted oblate opposite orientation orientations overall overpower parietal particularly pathways permutations physics planar planarity posterior primary probable processes radial recent recruited reduction reductions relatively reported resolution restricted scenario seems sensitive sensitivity shed shot significance slightly smith spatial spatially specifically spherical stage stages statistical steady stretches structural structures subjects submitted superior system temporal tensor though together tract transversely twice typical unchanged underlying uniformity variety whereby widespread words