Diffusion-weighted magnetic resonance imaging: theory and potential applications to child neurology.

Magnetic resonance imaging (MRI) is an excellent tool for the investigation of neurological disorders in children. Diffusion-weighted MRI (DWI) is sensitive to the diffusion (or molecular displacement) of water in tissue. The purpose of this article is to describe briefly the basic theory behind DWI and to discuss its potential applications to neurological disorders in children. We demonstrate that DWI is a sensitive technique for the detection of acute brain injury, and that it is well suited for monitoring brain development, particularly myelination and white matter changes.