Ben Jeurissen1, Alexander Leemans2, Jacques-Donald Tournier3, 4, Derek K. Jones5, Jan Sijbers1
1Vision Lab, University of Antwerp, Antwerp, Belgium; 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 3Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Victoria, Australia; 4Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia; 5CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom
A recent study, using high quality diffusion weighted data and CSD, has shown that multiple fiber orientations can be detected consistently in approximately 90% of all WM voxels. In this work, we assess the impact on DTI fiber tractography and WM integrity metrics by measuring: 1) the angle between the primary DTI eigenvector and the nearest CSD orientation; 2) the volume fraction of the non-dominant CSD fiber orientations. We show that errors in the DTI fiber orientations are widespread throughout the WM and that many voxels contain contributions from non-dominant orientations that would be sufficiently large to affect tensor-derived measures.