Single channel head coil

All children were scanned without sedation on a 3 Tesla Siemens Allegra MRI (Erlangen, Germany) at the Cape Universities Brain Imaging Centre (CUBIC) in South Africa with a single channel head coil according to protocols that had been approved by the Human Research Ethics Committees of the participating institutions. Parents/guardians provided written informed consent and children oral assent. Children were first familiarized with the scanning procedures on a mock scanner.
For each child we acquired a structural T1-weighted (T1w) volume using a volumetric navigated (Tisdall et al., 2012 (link)) multiecho magnetization prepared rapid gradient echo (MEMPRAGE) sequence (van der Kouwe et al., 2008 (link)) (voxel size = 1.3 × 1.0 × 1.0 mm³, FOV = 224 × 224 × 144 mm³, TR = 2,530 ms, TI = 1,160 ms, TEs = 1.53/3.19/4.86/6.53 ms, flip angle = 7°) and a pair of diffusion weighted data sets with opposite phase encodings (here, anterior-posterior and posterior-anterior, AP-PA) for EPI distortion correction during processing (Irfanoglu et al., 2012 (link)) using a volumetric navigated (Alhamud et al., 2012 (link)) twice-refocused spin echo sequence (voxel size = 2.0 × 2.0 × 2.0 mm³, matrix size = 112 × 112 × 72, FOV = 224 × 224 × 144 mm³, TR/TE = 10,000/86 ms, 30 non-collinear gradient directions with DW factor b = 1, 000 s mm⁻², and four non-DW b = 0 s mm⁻² (b₀) acquisitions).

Brain images were acquired using a 3.0T Allegra system (Siemens, Erlangen, Germany) with a single-channel head coil. Echo-planar imaging (EPI) was used for each functional run, that included 203 volumes with 32 axial slices parallel to the anterior and posterior commissural plane; in-plane field of view (FOV) of 220 mm, 64 × 64 matrix; 4 mm slice thickness with 0.4 mm gap; echo time (TE) 25 ms; repetition time (TR) 2000 ms; flip-angle 90°. Co-planar high-resolution T2 anatomical scans were also acquired for functional to structural co-registration purposes; 32 slices; FOV 220 mm; 256 × 256 matrix; slice thickness 4 mm with 0.4 mm gap. For normalization of brain images to standard space, 3D magnetization-prepared rapid gradient-echo (MPRAGE) T1 structural image; 192 sagittal slices; FOV 240 mm; 192 × 192 matrix; slice thickness 1.2 mm.