METHODS: T1- and T2-weighted MRI sequences were evaluated for tissue contrast consistency. Macrostructural and microstructural metrics, including craniofacial dimensions, skull base angles, corpus callosum thickness, and deep grey matter volumes, were quantified. Inter-rater reliability was assessed using the intraclass correlation coefficient (ICC), and independent t-tests evaluated cross-species variations.
RESULTS: Both species exhibited highly conserved tissue contrast patterns, characterised by grey matter hypointensity on T1-weighted images and hyperintensity on T2-weighted sequences. However, significant structural divergence was identified in specialised regions; the human brain demonstrated marked cranial base flexion (133° vs. 149° in the NHP) in addition to a profoundly expanded corpus callosum (genu: 1.05 cm vs. 0.28 cm) and a pronounced, non-uniform enlargement of higher-order frontal and temporal association cortices.
CONCLUSION: While fundamental tissue and structural architectures are highly conserved, the human paediatric brain displays selective, non-uniform expansion of higher-order cognitive networks rather than simple scaling. This comparative baseline validates the translational utility of NHP models while providing a practical, localised anatomical guide for Malaysian neuroscientists.