Dr. J-Donald Tournier is a Senior Lecturer within the department of Biomedical Engineering at King’s College London, embedded within the department of Perinatal Imaging and Health and the Centre for the Developing Brain (CDB). Dr Tournier has made key contributions to the field of diffusion MRI, particularly local modelling of fibre architecture, tractography, and group analysis of diffusion MRI data. These include the spherical deconvolution method for resolving the so-called crossing fibre problem (Tournier et al., 2004 ; 2007 & 2008) ; methods to improve the accuracy of tractography (Tournier et al., 2012 ; Smith et al., 2012 ; Smith et al., 2013) ; methods for orientationally-resolved voxel-wise analysis of group data (Raffelt et al., 2012 & 2015) ; and methods for the analysis of multi-shell diffusion MRI data (Jeurissen et al., 2014). These techniques have all been made freely available via the MRtrix software package (www.mrtrix.org), and are being used in many clinical and research studies worldwide. These methods are currently being implemented by Siemens for distribution on the current generation of MRI scanners.

Lecture abstract : Group comparisons of diffusion MRI data : Fixel-based analysis

Diffusion MRI is unique in its potential to probe the microstructure features of living tissue non-invasively, and has been used extensively to investigate brain white matter and its disorders. Many of these studies rely on voxel-wise comparisons across groups, to identify regions of the brain where microstructural features differ. However, many of these studies have so far relied on the widely-used diffusion tensor model, which introduces difficulties in interpretation of findings, with many studies showing opposite effects from those expected, due primarily to the issue of crossing fibres. Fixel-based analysis is a framework for the group-wise analysis of next-generation microstructure models to deal with these issues.

Contact : aattye@chu-grenoble.fr