MR of acute experimental allergic encephalomyelitis.

Acute experimental allergic encephalomyelitis, an animal model of CNS inflammatory and demyelinating disease, was produced in guinea pigs and imaged with MR. Correlation of histopathology with MR revealed acute mononuclear perivascular inflammatory changes and edema corresponding to the high-intensity abnormalities observed on long repetition time (TR) images. Our results suggest that in acute multiple sclerosis the high intensity noted on long TR images may be secondary to associated inflammatory changes rather than to demyelination.