12 channel head coil

All diffusion images were acquired on a General Electric MR750 3.0 Tesla scanner with a 12-channel head coil. Diffusion scans and their reverse phase images were acquired using spin-echo EPI (TR/TE = 11 650/70 ms, slice thickness = 2.0 mm, field of view = 256 mm, matrix size = 128 × 128, 72 slices). The reverse phase data included b0 images only and were collected to allow for distortion correction. Diffusion data were collected along 60 diffusion directions with a b-value of 1500 s/mm².

MR imaging for the DCD1 and controls1 groups was performed at the Seaman Family MR Research Center in Calgary, Alberta, on a 3 Tesla General Electric (GE) Signa scanner with a 12-channel head coil (GE Healthcare, Milwaukee, WI, USA). A T1‐weighted spoiled gradient echo pulse sequence was acquired at rest (flip angle = 13°, repetition time = 7.4 ms, echo time = 3.1 ms, field of view = 256 mm, matrix = 256 × 256 pixels, slice thickness 0.8 mm, isotropic).
MR imaging for DCD2 and controls2 groups took place at the Alberta Children’s Hospital, Calgary, Alberta, on a GE 3 Tesla MR750w research system, equipped with a 32-channel head coil and 70 cm wide bore (GE, Waukesha, WI). T1-weighted images were acquired at rest (flip angle = 10°, repetition time = 8.2 ms, echo time = 3.2 ms, field of view = 256, matrix = 512 × 512, slice thickness 0.8 mm, isotropic).

MRI data were acquired on a GE 3.0 MRI scanner (General Electric systems, USA) with a 12-channel head coil. The MRI scanning included T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and fluid-attenuated inversion recovery (FLAIR) sequences. Resting-state (rs) fMRI data were obtained using a T2-weighted gradient-echo, echo-planar imaging (EPI) sequence with the following parameters: repetition time (TR) = 2,000 ms, echo time (TE) = 30 ms, flip angle = 90°, slice thickness = 4 mm, acquisition matrix = 64 × 64, voxel size = 3 × 3 × 3 mm³. For each subject, 32 continuous axial slices per volume and a total of 360 volumes were acquired in 6 min. During the scanning, all lights were switched off and participants placed cotton in their ears to reduce sound. Subjects were instructed to relax in a supine position, breathing normally, and keeping still while not thinking about anything or falling asleep. Schelten's scale was used to evaluate the degree of white matter lesions.

MRI data were acquired on a 3 T MRI scanner (MR750; GE Discovery, Milwaukee, WI, USA) equipped with a 12-channel head coil at Kurihama Medical and Addiction Center. Resting-state fMRI data were acquired using an echo-planar imaging sequence (echo time = 30 ms, repetition time = 2500 ms, flip angle = 80°, field of view = 212 × 212 mm², matrix size = 64 × 64, voxel size = 3.3 × 3.3 × 4.0 mm, slice thickness = 3.2 mm, 240 volumes, 40 axial slices). During acquisition of resting-state fMRI data, participants were instructed to lie quietly with their eyes open and fixated on a crosshair. Also, for image processing, T1-weighted whole brain anatomical data were acquired using a BRAVO sequence (echo time = 3.064 ms, repetition time = 7.028 ms, inversion time = 650 ms, flip angle = 8°, field of view = 256 × 256 mm², matrix size = 256 × 256, slice thickness = 0.9 mm, 200 sagittal slices).

All participants were scanned using a GE Signa HDX 3.0T magnetic resonance imaging scanner with a standard 12-channel head coil at The First Affiliated Hospital of China Medical University. Head motion was minimized with foam padding. Diffusion-weighted images were acquired using a spin-echo planar imaging sequence parallel to the anterior-posterior commissure plane with the following parameters: TR = 17000 ms, TE = 85.4 ms, image matrix = 120 × 120, field of view = 240 × 240 mm², 65 contiguous slices of 2 mm without gap, 25 noncollinear directions, and one no diffusion-weighting baseline image.
Image preprocessing was performed using PANDA (http://www.nitrc.org/projects/panda), a fully automated program for processing of brain diffusion images. After motion and eddy current correction were performed, individual FA images of native space were registered to the FA template in MNI (Montreal Neurological Institute) space, followed by resampling the images to a customized spatial resolution 1 × 1 × 1 mm with subsequent warping transformations. Lastly, the FA images were smoothed by a 6 mm Gaussian kernel to reduce noise and misalignment. The resulting images were then used in statistical analyses.

fMRI was performed 5 hours after first drug/placebo administration. Data were acquired on a MR750 3-Tesla scanner with a 12-channel head coil (GE Healthcare, Chicago, IL); 180 volumes were acquired per functional run using a T2*-weighted echo-planar imaging sequence (repetition time = 2000 ms, echo time = 30 ms, field of view = 22.1 cm, flip angle = 75°, 41 slices, resolution = 3.3 mm³), with 4 initial volumes discarded to allow for magnetization equilibration effects. Cardiac signals were recorded with a plethysmograph, while respiration was measured using a respiratory belt. A high-resolution T1-weighted image was also acquired (repetition time = 7.31 ms, echo time = 3.02 ms, 256 × 256 matrix, 196 slices, voxel size = 1.2 × 1.05 × 1.05 mm).

Structural images were acquired on a General Electric MR750 3.0-Tesla MR scanner with a 12-channel head coil. We acquired 1 T1-weighted 3-dimensional Magnetization Prepared-Rapid Gradient Echo scan per participant (scanning parameters: repetition time (TR)/echo time (TE) 7,312/3.02 ms, flip angle 11°, 256 × 256 matrix, 1.2-mm thick, 196 sagittal slices, field of view = 270). Cortical thickness, surface area, volume, and local gyrification index as well as subcortical volumes were quantified using FreeSurfer 6.0.0 (http://surfer.nmr.mgh.harvard.edu). The procedure has been described in detail elsewhere (64 (link)–68 (link, link, link, link)). Smoothing was performed with a 10-mm kernel at full width/half max (FWHM) for cortical thickness, surface area, and volume. As local gyrification index already is a smooth measure, we only applied a 5-mm FWHM kernel for smoothing.