Diffusion Tensor Imaging of 7.0T Magnetic Resonance on Cerebral Cortex and Corpus Callosum Lesions in Experimental Autoimmune Encephalomyelitis / 中国医学影像学杂志

ABSTRACT

Purpose Cortex is one of the frequently involved sites of multiple sclerosis (MS),and the cortex and corpus callosum lesions of MS are gradually concerned.The study aims to observe the changes of cerebral cortex and corpus callosum of MS in experimental autoimmune encephalomyelitis (EAE) model by using 7.0T MRI diffusion tensor imaging (DTI).Materials and Methods Twenty female C57BL/6 mice of 6-8 week old were enrolled in the study,10 of which were induced by MOG35-55 to make EAE models and the rest 10 of which were taken as control group.On the 20 days after model establishment,the head T2WI and DTI were performed on both control and EAE mice.DTI quantitative indicators such as fractional anisotropy (FA),mean diffusivity (MD),axial dispersion coefficient λ//,and radial dispersion coefficient λ ⊥ in region of interest including bilateral prefrontal cortex,bilateral cingulate cortex and corpus callosum were compared between the two groups.Results No obvious lesions were observed on the T2WI in both control and EAE groups.In the experimental group,the FA mapping suggested the integrity of the left side of the corpus callosum was destroyed.The FA,MD,λ// λ ⊥ of bilateral prefrontal cortex and corpus callosum showed significant difference between experimental group and control group (P＜0.05);the increase of λ ⊥ in bilateral cingulate was significantly different from that in the control group.Meanwhile,HE staining in the experimental group showed that inflammatory cells gathered around the cortical and subcortical vessels.The LFB staining in experimental group showed a bit paler than that in the control group,and the corpus callosum showed patchy demyelination.Conclusion The technique of 7.0T MRI DTI sequence can detect cortex and corpus callosum lesions which cannot be found by conventional MRI,so that it provides radiological evidence for the study of MS with cortex and corpus callosum lesions.