THE ROLE of magnetic resonance imaging (MRI) in the diagnosis of stroke is expanding. Diffusion-weighted imaging (DWI) and related MRI techniques are now commonly used in the evaluation of patients who have had a stroke; however, little is known about DWI findings in venous infarction. Diffusion-weighted imaging can disclose ischemic cell damage within minutes and differentiate cytotoxic from vasogenic edema, which conventional MRI cannot. This may make DWI very useful for the diagnosis of cerebral venous infarction. The article in this issue of the ARCHIVES by Chu et al1 represents a significant addition to the limited experience with DWI in venous infarction.