Magnetic resonance (MRI) is the onlymethod of imaging which it makes possible visualisation of brain myelinization process in vivo. Due to a higher content of water and a low content of lipids, the non-myelinized white matter in newborn creates an inverse image when compared with myeliniyating matter of the adult brain (lower intensity in T1 WI and higher intensity in T2 WI, compared to the grey matter). The patients (up to two years old) were divided into four groups, which were characteristic by myelinization of certain anatomic structures, which is possible tomonitor by MRI.MR image of a child brain corresponds to MRI of the adult brain in T1 WI at the end of first year of age and in T2 WI at the end of second year of age.

        Key words: magnetic resonance imaging, brain, neonatal, suckling, physiological myelinization