MR MICROSCOPY OF TRANSGENIC MICE THAT SPONTANEOUSLY ACQUIRE EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS

Pathology of fixed spinal cords from transgenic mice with a myelin bas ic protein (MBP) specific T cell receptor was investigated. These mice spontaneously acquire the demyelinating disease experimental allergic encephalomyelitis (EAE). Several complementary imaging modalities, al l on the same tissues, were used to visualize lesions; these included high-field (11.7-T) microscopic diffusion tensor imaging (DTI), T-2-w eighted imaging, and optical microscopy on histological sections. Lesi ons were predominantly in white matter around meninges and vasculature and appeared hyperintense in anatomical images. DTIs showed reduced d iffusion anisotropy in the same hyperintense regions, consistent with inflammation and edema. Histology in the same tissues exhibited the ch aracteristic pathology of EAE, Two techniques for visualizing the effe ctive diffusion tensor fields are presented, which display direction, organization, and integrity of neuronal fibers. It is shown that DTI o ffers intriguing possibilities for visualizing axonal organization and lesions within white matter.