Magnetom trio 3t system

In vivo MRS data were acquired in single healthy human volunteers using a 3T MAGNETOM Trio system (Siemens, Erlangen, Germany) with a body coil transmitter and a 32-channel head receiver array coil. Data were acquired from a region of interest in the medial prefrontal cortex (15 × 30 × 15 mm³) using the SPECIAL sequence (11 (link)) (repetition time [TR]/TE = 3200/8.5 ms; spectral width = 4000 Hz; 4096 points; 256 averages; 16 phase cycle steps). Six outer volume suppression slabs were applied (one on each side of the cubic voxel) to suppress outer volume signals due to imperfect localization and to minimize ISIS subtraction artifacts. Following data acquisition, the interleaved inversion-on and inversion-off scans were subtracted, resulting in 128 fully localized spectra. Spectral registration was then performed using a frequency range of −2 ppm to 4.2 ppm, to include only the part of the spectrum upfield of water. Because the true frequency and phase drift of this in vivo dataset are not known, the performance of the registration was assessed simply by inspection of the estimated frequency and phase drift curves, and by visual assessment of the alignment of the averages before and after correction.

Eighty five participants (43 female, mean age = 28.79 years; min= 18; max= 54) participated in this study. All participants provided informed consent in accordance with guidelines set by the Institutional Review Board of the University of Colorado Boulder. Seven participants were excluded due to incomplete scans, resulting in a total sample size of 78 (42 female, mean age = 28.73 years; min= 18; max= 54). Participants underwent fMRI scanning while viewing six videos labeled based on a normed sample as “loss” (i.e., ”sadness”), “anger,” or “disgust” (two videos per category). Videos were between 60 and 120 seconds in length (mean length 106 seconds). Following each video clip, participants provided a valence rating (i.e., “How negative or positive do you feel right now?”) for a duration of 90s followed by a jittered ITI between 120 and 150ms.
Magnetic Resonance Imaging (MRI) scans were acquired on a Siemens MAGNETOM Trio 3T system (Siemens Medical Solutions, Erlangen, Germany) using a 32-channel head coil and included a structural MEMPRAGE scan (TR = 2530ms, TE1 = 1.64ms, TE2 = 3.5ms, TE3 = 5.36ms, TE4 = 7.22ms, TE5 = 9.08ms, FA = 7°, FOV = 256mm, voxel size 1mm isotropic, 192 slices) and a functional MRI scan (TR = 1300ms, TE = 25ms, FA = 50°, voxel size 3.4mm isotropic, FOV = 220mm, 26 slices).