The earliest manifestation of focal encephalitis on diffusion-weighted MRI

We report the case of an adult patient with a focus of meningioencephalitis in whom the earliest magnetic resonance imaging (MRI) manifestation was hyperintense signal on diffusion-weighted (DW) sequence only. To our knowledge, this is the first adult encephalitis case to be reported with the MRI diffusion-weighted pulse sequence being the only positive MRI finding. A brief review of the pertinent literature is included.