Diffusion imaging of experimental allergic encephalomyelitis

Abstract

Diffusion‐weighted magnetic resonance imaging (MRI) was compared with T₂‐weighted MRI in longitudinal studies of experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis, in five monkeys (Macaca fascicularis). In a region of the brain that had highly directional myelinated fibers (internal capsule) sequential changes were identified on diffusion‐weighted images on and before the day these changes were detected on conventional T₂‐weighted images. Changes were also identified on diffusion‐weighted images in brain areas that did not develop T₂‐weighted abnormalities. This result suggests that diffusion‐weighted image intensities are sensitive to pathologic conditions of the brain that can not be seen on T₂‐weighted images.