02.08.2017 - New paper accepted
The paper AxTract: Toward Microstructure Informed Tractography has been accepted in Human Brain Mapping.
Diffusion-weighted (DW) magnetic resonance imaging (MRI) tractography has become the tool of choice to probe the human brain’s white matter in vivo. However, tractography algorithms pro- duce a large number of erroneous streamlines (false positives), largely due to complex ambiguous tis- sue configurations. Moreover, the relationship between the resulting streamlines and the underlying white matter microstructure characteristics remains poorly understood. In this work, we introduce a new approach to simultaneously reconstruct white matter fascicles and characterize the apparent dis- tribution of axon diameters within fascicles. To achieve this, our method, AxTract, takes full advantage of the recent development DW-MRI microstructure acquisition, modeling, and reconstruction techni- ques. This enables AxTract to separate parallel fascicles with different microstructure characteristics, hence reducing ambiguities in areas of complex tissue configuration. We report a decrease in the incidence of erroneous streamlines compared to the conventional deterministic tractography algorithms on simulated data. We also report an average increase in streamline density over 15 known fascicles of the 34 healthy subjects. Our results suggest that microstructure information improves tractography in crossing areas of the white matter. Moreover, AxTract provides additional microstructure information along the fascicle that can be studied alongside other streamline-based indices. Overall, AxTract pro- vides the means to distinguish and follow white matter fascicles using their microstructure characteris- tics, bringing new insights into the white matter organization. This is a step forward in microstructure informed tractography, paving the way to a new generation of algorithms able to deal with intricate configurations of white matter fibers and providing quantitative brain connectivity analysis.
AxTract: Toward Microstructure Informed Tractography
Gabriel Girard, Alessandro Daducci, Laurent Petit, Jean-Philippe Thiran, Kevin Whittingstall, Rachid Deriche, Demian Wassermann, Maxime Descoteaux
Human Brain Mapping
Link to publisher.