MRI of the central nervous system in neonates and young children.

Twelve normal neonates and young children, ages 32 weeks gestation to 20 months, and 22 abnormal children up to four years old had MRI scans using a 0.5 T superconducting scanner. A faint signal that was presumed to be myelin was detected in the thalami at 32 weeks; myelination of the occipital lobes was present at full term, and visible throughout the hemispheres by 8 weeks of age. Anatomical locations of congenital lesions were well demonstrated, especially in sagittal views. The signal changes of perinatal abnormalities, such as hemorrhage and hemiatrophy, were often specific. Abnormal position of the spinal cord, spinal lipomas, and other congenital lesions were also well visualized.