Normal postnatal development of the corpus callosum as demonstrated by MR imaging.

Sixty-three patients, 3 days to 12 months old, were examined by MR imaging to evaluate the normal development of the corpus callosum in the first year of life. During the first month of life the corpus callosum is uniformly thin and of the same signal intensity as white matter throughout the brain. During the second month, a variable spurt of growth occurs in the genu, followed by a similar period of rapid growth in the splenium between 4-6 months of age. High signal intensity on T1-weighted images related to the myelination process begins to appear in the splenium by about 4 months and in the genu by about 6 months. The corpus callosum has an adult appearance on sagittal scans by about 8 months of age.