3t trio mr system

fMRI scans were completed on a Siemens 3T TRIO MR system with an eight channel phased array head coil. fMRI volumes were acquired using the following parameters: 36 3.5-mm oblique axial T2*-weighted gradient-echo EPI slices, with 2000 ms TR, 28 ms TE, 60 degree flip angle and 240 mm × 240 mm field of view in a 64 × 64 matrix. Each functional run was preceded by five images of unanalyzed data to allow steady-state magnetization to be achieved. Preprocessing of fMRI volumes with the Statistical Parametric Mapping, version 8 (SPM8) software package included temporal and spatial realignment, normalization to the EPI template, .001 Hz high-pass filtering and spatial smoothing with 8 mm FWHM Gaussian kernel. We excluded two SZ and one HC subject for exhibiting greater than 4 mm within-run movement. This threshold was chosen as the size of a voxel was 4 mm in plane. A comparison of mean framewise displacement (Power et al., 2014 (link)) of included subjects during scanning indicated absence of significant between-group difference in this variable (p=0.292). In addition, we also found no group difference in the frame-by-frame changes in any of the six movement parameters, p>0.13. We also conducted additional post-hoc analyses, described below, to rule out the possibility of head movement confounding our results.

All scans were acquired using a 3T Trio MR System with a 32-channel, phased-array head coil (Siemens Healthcare, Erlangen, Germany). Structural scans were acquired using a three-dimensional T1-weighted MEMPRAGE pulse sequence with a voxel resolution of 1 mm³, flip angle (FA) = 7°, echo time (TE) = 1.61 ms, inversion time (TI) = 1200 ms, and repetition time (TR) = 2530 ms.
For functional images, the blood oxygen level dependant (BOLD) signal was measured using a gradient-echo, echo-planar imaging pulse sequence (EPI) with prospective acquisition correction (PACE) (Dale et al., 1999 ) for motion with imaging parameters: TR = 2 s, TE = 30 ms, FA = 90°, in-plane resolution of 3 × 3 mm², number of slices = 32, slice thickness = 3.5, and slice gap = 10%, providing coverage around the STG.