Infant Neuroimaging During Natural Sleep

Participants were scanned without sedation during natural sleep using the feed-and-wrap protocol^{50 (link)}. Infants were fed, bundled with multiple levels of ear protection, and immobilized in an MRI-safe vacuum swaddle. Heart rate and O₂ saturation were continuously monitored during all scans. The scans were performed using a 3 T Siemens (Erlangen, Germany) Prisma MR system with a 32-channel parallel receiver head coil. Functional runs were acquired using a multiband T2*-sensitive gradient-recalled, single-shot echo-planar imaging pulse sequence (TR = 1 s, TE = 31 ms, FoV = 185 mm, flip angle 62°, multiband = 4, matrix size 92 × 92). Each volume consisted of 60 slices parallel to the bi-commissural plane (slice thickness 2 mm, no gap). We collected 4–5 functional runs, each comprised of 360 volumes. Each neonate had on average 11.6 min (SD = 1.34) of usable functional data with an average frame-to-frame displacement of 0.03 (SD = 0.02, Min: 0.01, Max: 0.10). High-resolution T1-and T2-weighted 3D anatomical scans were acquired using an MPRAGE sequence (TR = 2400 ms, TE = 1.18 ms, flip angle = 8°, thickness = 1 mm, in-plane resolution = 1 mm × 1 mm, matrix size = 256 × 256) and a SPACE sequence (TR = 3200 ms, TE = 449 ms, thickness = 1 mm, in-plane resolution = 1 mm × 1 mm, matrix size = 256 × 256).