Intera achieva 3.0 tesla mr system

MR data was acquired on a Philips (Best, Netherlands) Intera Achieva 3.0 Tesla MR system at Trinity College Institute of Neuroscience, Dublin. One hundred and eighty axial T1-weighted images (T1W-IR1150 sequence, TE = 3.8 ms, TR = 8.4 ms, field of view (FOV) 230 mm, 0.898 × 0.898 mm 2 , in-plane resolution, slice thickness 0.9 mm, flip angle alpha = 8°) were acquired. Whole brain, high angular diffusion imaging (HARDI) [47, 48] was acquired using a spinecho echo-planar imaging pulse sequence (TE = 52 ms, TR = 11,260 ms, flip angle alpha = 90°), FOV 224 mm, 60 axial slices, 2 mm 3 isotropic voxels, b-value = 1500 s mm -2 in 61 non-collinear gradient directions. A b0 image was also acquired.

All scanning was conducted on a Philips Intera Achieva 3.0 Tesla MR system (Best, The Netherlands) equipped with a mirror that reflected the visual display, which was projected onto a panel placed behind the participants' head outside the magnet. The mirror was mounted on the head coil in each participant's line of vision. Each scanning sequence began with a reference scan to resolve sensitivity variations. A parallel sensitivity encoding (SENSE) approach with a reduction factor of 2 was utilised for all T1-weighted image acquisitions (Pruessmann et al., 1999) . 180 high-resolution T1-weighted anatomic MPRAGE axial images (FOV 230 mm, thickness 0.9 mm, voxel size 0.9×0.9×0.9) were then acquired (total duration 325 s), to allow subsequent activation localization and spatial normalization. Functional data were acquired using a T2* weighted echo-planar imaging sequence collecting 32 non-contiguous (10% gap) 3.5 mm axial slices covering the entire brain (TE=35 ms, TR=2000 ms, FOV 224 mm, 64×64 mm matrix size in Fourier space). Functional scans had a total duration of 340 s per run.