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

During the last decade, diffusion-weighted imaging (DWI) has become an important tool in the evaluation of a variety of disorders of the central nervous system in children. DWI relies on variability in the diffusivity of water molecules in the presence of a supplemental diffusion-sensitizing gradient to produce image contrast. Pathologic states alter the diffusion characteristics of brain water in a reproducible fashion. In this review, the DWI appearances of a number of common abnormalities of the brain in infants and children are presented.