Diffusion-weighted imaging in moyamoya disease

Moyamoya disease is characterized by progressive intracranial vascular sten oses of the circle of Willis, resulting in successive ischemic events. We r eport serial diffusion-weighted imaging studies in a case of moyamoya disea se. A 4-year-old right-handed patient presented with multiple infarcts in t he right and left hemispheres. Each new infarct was unambiguously recognize d as bright on diffusion-weighted imaging. previous infarcts, readily detec ted on other magnetic resonance imaging sequences, were not bright on diffu sion-weighted imaging. The patient subsequently underwent bilateral synangi osis. In this case, the diffusion-weighted images were helpful in assessing the extent of infarcts, determining the age of the lesion, and correlation with new clinical findings. We emphasize the usefulness of diffusion-weigh ted imaging for following the clinical course of children with moyamoya dis ease, in whom new focal deficits are highly suspicious of new infarcts.