BRAIN CAST: Children's Age- and Sex-specific Templates — a library of 28 age- and sex-specific pediatric brain MRI templates (ages 5–18)

BRAIN CAST (Children's Age- and Sex-specific Templates) is a library of 28 T1-weighted brain MRI templates covering every year of age from 5 to 18, separately for males and females, derived entirely from the Healthy Brain Network (HBN). Each age×sex set contains five NIfTI-1 files on that template's native voxel grid: the T1-weighted group-average template, gray-matter / white-matter / CSF tissue probability maps, and a binary brain mask (28 × 5 = 140 files). Templates are distributed at either 0.8 mm isotropic (224×320×213) or 1.0 mm isotropic (176×256×170), depending on the underlying acquisition, in approximate MNI orientation but not resampled to the MNI152 grid. Templates were constructed from 1,272 quality-screened HBN scans using iterative groupwise diffeomorphic registration in ANTs, following a constraint-aware pediatric preprocessing pipeline (conservative denoising, CSF-anchored intensity normalization, deep-learning skull stripping, MRIQC-guided quality control). Tissue probability maps are cohort probability maps: each voxel is the fraction of that stratum's contributing subjects assigned to the tissue class. Filenames follow the tpl-/label- conventions used by TemplateFlow for redistributable reference spaces. A per-template cohort summary (participants.tsv) and SHA 256 checksums for every file are included. BRAIN CAST was developed at the NSF IUCRC Building Reliable Advances and Innovation in Neurotechnology (BRAIN) Center, University of Houston (https://brain-d10.egr.uh.edu), in the Laboratory for Non-Invasive Brain-Machine Interface Systems, Department of Electrical and Computer Engineering. Supported in part by NSF IUCRC BRAIN Award #2137255. Computational resources were provided by the University of Houston Research Computing Data Core (https://www.uh.edu/research/rcdc/index.php). BRAIN CAST is derived from the Healthy Brain Network and is NOT a Child Mind Institute product. HBN source data are distributed by the Child Mind Institute through INDI under their own data-use terms and are not redistributed here. The released templates are group-level averages containing no subject-identifiable data. Version 1.1.0 (30 July 2026). The age-11 female stratum has been rebuilt. participants.tsv is updated accordingly (age-11 female n = 78 → 52; library total 1,298 → 1,272 = 757 male + 515 female) and CHECKSUMS.sha256 has been recomputed for the whole deposit. The other 27 age × sex strata are unchanged from version 1.0.0 and are byte-identical.