Stephen Rose1, Kerstin Pannek1, Fusun Baumann2, Robert Henderson2
1Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia; 2Neurology, Royal Brisbane & Women's Hospital, Brisbane, Queensland, Australia
Structural connectivity analyses, using diffusion tractography in conjunction with cortical parcellation of structural MRI, are useful techniques for studying neurological disease processes associated with multiple white matter (WM) networks. In this study, we introduce a new quantitative connectivity measure based on the amplitude of the Fibre Orientation Density (FOD) function and apply this strategy to measure the integrity of corticomotor WM pathways in patients with Amyotrophic Lateral Sclerosis (ALS). Compared to measures of fractional anisotropy, the FOD amplitude is less sensitive to contamination from crossing fibre tracts. This approach was found to provide new insight into brain plasticity in ALS.