Trio 3t mri scanner

Data were collected using a Siemens TRIO 3 T MRI scanner over a period of 12 sessions on separate days, each commencing at midnight. fMRI scan data from task and resting‐state scans were analyzed and T1‐weighted and T2‐weighted images were used to preprocess fMRI scans. Four T1‐weighted scans (0.8 mm isotropic, TR = 2400 ms, TE = 3.74 ms, T1 = 1000 ms, FA = 8°, 224 sagittal slices) and four T2‐weighted scans (0.8 mm isotropic, TR = 3200 ms, TE = 479 ms, 224 sagittal slices) were acquired per participant. Details on the MRA and MRV scans are provided in the original MSC study (Gordon et al., 2017 (link)).
Functional images were acquired using a gradient‐echo EPI BOLD sequence (TR = 2200 ms, TE = 27 ms, FA = 90°, voxel size = 4 × 4 × 4 mm³, 36 axial slices), with one gradient field map sequence collected in each session with the same prescription as the functional scans. For each participant, a total of 300 min of rest fMRI and 350 min of task fMRI scans were collected over 10 subsequent days. An eye‐tracker camera was used to assess participant wakefulness. In line with previous studies (Gordon et al., 2017 (link); Gratton et al., 2018 (link)), one participant, MSC08, was excluded from this study due to self‐reported sleep, prolonged eye closures, and a large amount of head motion.

MRI scans were acquired on a Siemens Trio 3T MRI scanner (Siemens Medical Solutions, Erlangen, Germany), with either an 8-channel (167 scans) or 32-channel head coil (447 scans). Standard TSE T2-weighted scans or proton density-T2 scans with voxel size of 0.6 × 0.6 × 3.0 mm³ were utilized for detection of hyperintensive signals in both MCP and globus pallidus (Figure 1A). We carefully distinguished the abnormal hyperintensities from hyperintensities associated with enlarged perivascular spaces, which appeared as either scattered thin linearly-shaped hyperintensities throughout the globus pallidus or oval-shaped hyperintensities, typically <5 mm in diameter, with a smooth boundary inferior to the globus pallidus. All images included in quantitative analyses were acquired using the 32-channel head coil. T1-weighted scans were obtained using the standard magnetization-prepared rapid gradient echo sequence. For iron quantification, the 3D T2^*-weighted multi-echo gradient recalled echo sequence was acquired in 64 axial slices of 2 mm thickness (no gap), with field of view = 224 mm², matrix size = 256 × 256, repetition time = 50 ms, echo time₁/spacing/echo time₈ = 4/5.7/44 ms, and flip angle = 25°.

Functional magnetic resonance imaging (fMRI) was performed using a Siemens Trio 3T MRI scanner. In each of the two runs per subject 515 functional images were acquired using a T2*-weighted echo-planar imaging (EPI) sequence covering the whole brain with 33 axial slices having a thickness of 3.4 mm (gap between slices 0.51 mm). Each slice had a resolution of 64 × 64 pixels and a field of view of 200 × 200 mm², resulting in a voxel size of 3.125 × 3.125 × 3.4 mm³. The echo-time (TE) was 30 ms, the flip-angle amounted to 75° and the repetition time (TR) was 1800 ms, which resulted in an acquisition time of 15 min and 45 s per functional run. The first three images of each run were discarded due to T1 stabilization effects. After the two functional runs an anatomical image was acquired with a T1-weighted magnetization prepared rapid gradient echo (MPRAGE) sequence yielding a resolution of 1 × 1 × 1 mm³ (TR: 1900 ms, TE: 2.52 ms, flip-angle: 9°).