Background and Aim:White matter myelination is a critical process in neurological development and maturation, which can be reliably assessed through brain MRI. This study aimed to evaluate the pattern of brain myelination in Iranian infants and compare it with global standard references—marking the first such investigation conducted in Iran.
Methods:This retrospective study analyzed existing data from 249 children under 24 months of age who underwent brain MRI for various clinical reasons but were deemed neurologically normal. Qualitative assessment of myelination was performed using T1- and T2-weighted images and FLAIR sequences. Myelination stages were compared across age groups using international standard references. For each age group, if more than 95% of cases exhibited patterns consistent with the global standards, the results were considered aligned with normal developmental milestones.
Results:Signal intensity changes on T1- and T2-weighted images corresponding to key myelination landmarks were documented across different age groups. At 2, 4, 8, 18, and 24 months of age, the myelination patterns on T1- and T2-weighted images were largely consistent with global standards. However, discrepancies were noted in other age groups. Additionally, FLAIR sequences showed inconsistent findings across nearly all age groups, except for children at 24 months.
Conclusion:The findings suggest that demographic factors such as ethnicity may not significantly influence the timeline of myelination. However, the variability observed in certain age groups—especially on FLAIR imaging—underscores the need for developing a region-specific nomogram for more accurate evaluation of brain myelination in Iranian children, ideally based on larger sample sizes.