Signa 3 tesla scanner

Images were acquired on a GE Signa 3 Tesla scanner equipped with a standard quadrature head coil. Functional T2* weighted images were acquired using a spiral sequence with 25 contiguous slices with 3.75×3.75×5 mm voxels (repetition time (TR) = 1500 ms; echo time (TE) = 30 ms; flip angle = 70°; field of view (FOV) = 24 cm). A T1-weighted gradient echo anatomical overlay was acquired using the same FOV and slices (TR = 225 ms, TE = 5.7 ms, flip angle = 90°). Additionally, a 124-slice high-resolution T1-weighted anatomical image was collected using spoiled-gradient-recalled acquisition (SPGR) in steady-state imaging (TR = 9 ms, TE = 1.8 ms, flip angle = 15°, FOV = 25–26 cm, slice thickness = 1.2 mm).

Using Presentation, we implemented a slow event-related paradigm (©Neurobehavioral Systems, Inc.,³) comprising two perceptual tasks defined as tone perception and vowel listening, a vowel articulation imagery task and a vowel production task. In perceptual trials, stimulus presentation lasted for 2 s and was followed by 8 s rest. Imagery/production trials started with 2 s stimulus presentation, then followed by 8 s maintenance phase, 2 s task execution (articulation imagery, or production of the same heard vowel) and finally 8 s rest. Globally, functional scans lasted 47 m, divided into 10 runs. All vowels and tones were presented twice to each subject, and their presentation order was randomized within and across tasks and subjects.
Functional imaging was carried out through GRE-EPI sequences on a GE Signa 3 Tesla scanner equipped with an 8-channel head coil (TR/TE = 2500/30 ms; FA = 75°; 2 mm isovoxel; geometry: 128 × 128 × 37 axial slices). Structural imaging was provided by T1-weighted FSPGR sequences (TR/TE = 8.16/3.18 ms; FA = 12°; 1mm isovoxel; geometry: 256x256x170 axial slices). MR-compatible on-ear headphones (30 dB noise-attenuation, 40 Hz to 40 kHz frequency response) were used to achieve auditory stimulation.

Imaging data were acquired on a General Electric Signa 3-Tesla scanner, and analyzed using the Statistical Parametric Mapping Software package (SPM8; University College London). An echo-planar single shot gradient echo T2*-weighted sequence was used to collect 23 axial slices of 5-mm thickness, parallel to the AC-PC-line (repetition time = 2,000 ms; echo time = 40 ms; field of view = 240 mm; 64 × 64 matrix, 3.75 × 3.75 mm voxels). The anatomical scan used a magnetization prepared gradient echo (MPRAGE) sequence to collect 180 1 mm sagittal slices (field of view = 256 mm; repetition time = 11.4 ms; echo time = 4.4 ms; matrix = 256 × 256; inversion time = 300 ms). Data were analyzed for subjects who successfully completed the task and stayed within 3.0 mm of motion in any plane.