Normal brain maturation in MRI.

Normal brain maturation was evaluated with MR imaging of 36 neonate to 2-year-old patients. The myelination process in centrum semiovale was quantitatively assessed in 50 6-months- to 15-year-old children, and 40 adults aged 16-60 years. Imaging was performed with a 0.35 T superconducting MR unit using spin echo pulse sequences. On T1-weighted images, three stages of maturation could be observed: (1) neonates within 1 month; (2) 1-6 months of age; and (3) adult configuration after 6-7 months of age. Also on T2-weighted images three maturation stages could be defined: (1) neonatal pattern in the first 6 months of life; (2) signal inversion between 6-18 months; and (3) adult appearance after 18 months. Thus, the combination of T1- and T2-weighted images could lead us to the assessment of brain maturation in infants younger than 2 years. The myelination process in centrum semiovale was fast during the first 3 years followed by slow progression until 20-30 years of age.