Each brain was segmented using an automated template-driven pipeline, and brain parenchymal fraction (BPF) and T2-hyperintense lesion volume (T2LV) were calculated for each MRI scan [24], [25].
It implies that age-inappropriate (e.g., the Chinese56 template, the US20 24 template) and nationality-inappropriate brain templates (e.g., U.S. children's templates, the US20 24 template) do not provide optimal reference MRIs for processing MR brain images of Chinese pediatric populations.
The head and brain templates were constructed using averaging techniques based on iterative methods that have become the norm for MRI template construction (Fonov et al., 2011; Sanchez et al., 2012a, b).
The whole-head and brain-extracted MRI volumes were performed separately to provide both head and brain templates.
One such method, tensor-based morphometry (TBM), uses nonlinear deformations to align each participant's MRI scan to an average brain template, and the degree of compression or expansion is used as a measure of regional brain volume.
In the absence of brain lesion, regular SyN warping was used for matching between the MNI single-subject brain template and the subject's MR image.
The preprocessing and data analysis were performed using our self-developed toolbox for voxel-wise analysis of rat brain images based on SPM8 (Welcome Department of Cognitive Neurology, London, UK), which comprised a FDG-PET rat brain template and atlas in Paxinos & Watson space [ 21].
Registration to a brain template and segmentation into cortex, white matter and CSF is currently performed mainly on 3D T1-weighted images.
We have previously created an [I]ADAM brain template and a predefined VOI (volume of interest) map for the automated registration and analysis of the [I]ADAM images [ 27].
The Chinese average head and brain MRI templates are publicly available for research including clinical and experimental studies of brain development.
