Diffusion-weighted imaging of the brain in neonates and infants.

Diffusion-weighted imaging provides novel and interesting insights into normal development and pathologic processes occurring in neonates and infants. Both myelinated and unmyelinated white matter show restricted diffusion. Focal infarction in perinatal stroke and more global injury associated with hypoxic ischemia encephalopathy produce high-signal lesions in the brain, in the acute phase. Diffusion-weighted imaging also demonstrates abnormalities of a variety of other diseases, when conventional imaging is relatively uninformative.