Tractostorm: Rater reproducibility assessment in tractography dissection of the pyramidal tract

Francois Rheault (1) , Alessandro de Benedictis , Alessandro Daducci , Chiara Maffei , Chantal M W Tax , David Romascano , Eduardo Caverzasi , Felix C Morency , Francesco Corrivetti , Franco Pestilli , Gabriel Girard , Guillaume Theaud , Ilyess Zemmoura , Janice Hau , Kelly Glavin , Kesshi M Jordan , Kristofer Pomiecko , Maxime Chamberland , Muhamed Barakovic , Nil Goyette , Philippe Poulin , Quentin Chenot , Sandip S Panesar , Silvio Sarubbo , Laurent Petit (2) , Maxime Descoteaux (1)

1 SCIL - Sherbrooke Connectivity Imaging Lab [Sherbrooke]
2 GIN - [GIN] Grenoble Institut des Neurosciences

Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called "virtual dissection". Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. The contribution of this study is to provide the first large-scale, international, multi-center variability assessment of the "virtual dissection" of the pyramidal tract (PyT). Eleven (11) experts and thirteen (13) non-experts in neuroanatomy and "virtual dissection" were asked to perform 30 PyT segmentation and their results were compared using various voxel-wise and streamline-wise measures. Overall the voxel representation is always more reproducible 1. CC-BY-NC-ND 4.0 International license available under a not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint (which was this version posted April 30, 2019. ; https://doi.org/10.1101/623892 doi: bioRxiv preprint than streamlines (≈70% and ≈35% overlap respectively) and distances between segmen-tations are also lower for voxel-wise than streamline-wise measures (≈3mm and ≈6mm respectively). This needs to be seriously considered before using tract-based measures (e.g. bundle volume versus streamline count) for an analysis. We show and argue that future bundle segmentation protocols need to be designed to be more robust to human subjectivity. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction techniques in this era of open and collaborative science.

Mots clés: Diffusion MRI; White Matter; Tractography; Bundle segmentation; Intra-rater; inter-rater; Reproducibility

Domaines: Neurosciences

Francois Rheault, Alessandro de Benedictis, Alessandro Daducci, Chiara Maffei, Chantal M W Tax, et al.. Tractostorm: Rater reproducibility assessment in tractography dissection of the pyramidal tract. 2019. ⟨hal-03007052⟩