title: Connectivity-based parcellation of the cortical mantle using q-ball diffusion imaging.
abstract: This paper exploits the idea that each individual brain region has a specific connection profile to create parcellations of the cortical mantle using MR diffusion imaging. The parcellation is performed in two steps. First, the cortical mantle is split at a macroscopic level into 36 large gyri using a sulcus recognition system. Then, for each voxel of the cortex, a connection profile is computed using a probabilistic tractography framework. The tractography is performed from q fields using regularized particle trajectories. Fiber ODF are inferred from the q-balls using a sharpening process focusing the weight around the q-ball local maxima. A sophisticated mask of propagation computed from a T1-weighted image perfectly aligned with the diffusion data prevents the particles from crossing the cortical folds. During propagation, the particles father child particles in order to improve the sampling of the long fascicles. For each voxel, intersection of the particle trajectories with the gyri lead to a connectivity profile made up of only 36 connection strengths. These profiles are clustered on a gyrus by gyrus basis using a K-means approach including spatial regularization. The reproducibility of the results is studied for three subjects using spatial normalization.
authors.affiliation: NeuroSpin Institut d'Imagerie BioMédicale, Commissariat l'Energie Atomique (CEA), Gif-sur-Yvette 91191, France. muriel.perrin@ge.com
authors.forename: Muriel
authors.initials: M
authors.lastname: Perrin
authors.forename: Yann
authors.initials: Y
authors.lastname: Cointepas
authors.forename: Arnaud
authors.initials: A
authors.lastname: Cachia
authors.forename: Cyril
authors.initials: C
authors.lastname: Poupon
authors.forename: Bertrand
authors.initials: B
authors.lastname: Thirion
authors.forename: Denis
authors.initials: D
authors.lastname: Rivière
authors.forename: Pascal
authors.initials: P
authors.lastname: Cathier
authors.forename: Vincent
authors.initials: V
authors.lastname: El Kouby
authors.forename: André
authors.initials: A
authors.lastname: Constantinesco
authors.forename: Denis
authors.initials: D
authors.lastname: Le Bihan
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mangin