David Raffelt1,2,
Olivier Salvado1, Stephen Rose3, Robert Henderson4,
Alan Connelly5,6, Stuart Crozier2, J.-Donald Tournier5,6
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).