Desktop version

Home arrow Computer Science arrow Computational Diffusion MRI: MICCAI Workshop, Athens, Greece, October 2016

Source

Material and Methods

Acquisition

73 right-handed healthy volunteers were scanned on a 3T MRI (Siemens MAG- NETOM Trio, Tim system) using a dedicated protocol [5] including: a MPRAGE sequence for the T1-weighted anatomy (1 mm isotropic; TE=2.98 ms; TR=2.3 s), a multiple-shell diffusion-weighted SE-EPI sequence (1.7 mm isotropic; TE=117 ms; TR=14s; 10 b-values from 300 to 3000 s/mm2 along 20 directions and 10 scans at b=0s/m2), an echo-planar sequence for the BOLD signal (3 mm isotropic; TE=2.4ms; TR=30ms) and a fieldmap calibration to remove distorsions. This protocol originally designed in the frame of the CONNECT project remains relevant according to the protocols presented in the NODDI paper by Zhang et al. [3] as the restricted number of directions has been counterbalanced with the high number of shells. Moreover, the restricted number of direction was not a problem to study the dendrites within the grey matter as they are isotropically distributed. The experimental fMRI protocol [6] is freely accessible for a set of subjects (http:// brainomics.cea.fr/localizer). This localizer protocol is a 5-min fMRI sequence that captures the cerebral bases of auditory and visual perception, motor actions, reading, language comprehension and mental calculation at an individual level. In this work, the functional contrasts which have been considered are: “right hand click minus left hand click” and “left hand click minus right hand click” for hands motor activations, “phrase video minus checkerboard” for reading activations and a visual contrast combining “right video click, left video click, video calculation, video sentence minus right audio click, left audio click, audio calculation, audio sentence”.

 
Source
Found a mistake? Please highlight the word and press Shift + Enter  
< Prev   CONTENTS   Next >

Related topics