Abstract #0671

Tensor Based Morphometry of White Matter Tracts using Fibre Orientation Distributions

David Raffelt^1,2, Olivier Salvado¹, Stephen Rose³, Robert Henderson⁴, Alan Connelly^5,6, Stuart Crozier², J.-Donald Tournier^5,6

¹The Australian E-Health Research Centre, CSIRO, Brisbane, QLD, Australia; ²Biomedical Engineering, School of ITEE, University of Queensland, Brisbane, QLD, Australia; ³Centre for Advanced Imaging, University of Queensland, Brisbane, QLD, Australia; ⁴Department of Neurology, Royal Brisbane & Women's Hospital, Brisbane, QLD, Australia; ⁵Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, VIC, Australia; ⁶Department of Medicine, University of Melbourne, Melbourne, VIC, Australia

Tensor based morphometry (TBM) exploits information obtained during spatial normalisation to investigate differences in brain anatomical structure across populations and time. Using a cohort of Motor Neurone Disease and healthy subjects, we demonstrate a novel method for investigating morphological changes to white matter. We used a Fibre Orientation Distribution (FOD) registration method to normalise data towards a group average template, followed by group average fibre tractography to identify voxels and orientations of interest. Voxel-based analysis was then performed using the inferred fibre orientations to compute differences in perpendicular cross sectional area (and therefore differences in the number of axons).