Indian Brain Aging: Decade-Wise Templates

High-resolution 3T MRI scans of healthy Indian subjects aged 20–80 years were collected from multiple sites across India with appropriate ethical approvals. Approximately 26 scans were included per decade, with gender-balanced representation, comprising only right-handed, physically and psychologically healthy individuals with no history of neurological disorders or head injury. Pregnant women, prematurely born individuals, and those with long-term medical conditions were excluded. All scans were reviewed by experienced medical experts to confirm the absence of structural abnormalities. All images were preprocessed using the complete FSL pipeline (fsl_anat), which includes brain extraction, bias field correction, tissue segmentation, and nonlinear registration to ensure consistency and reliability. For brain aging analysis, skull-stripped images were grouped into six age decades (20–80 years) and processed using the ANTs group registration framework to generate Indian population–specific, gender-balanced, decade-wise brain templates, w.