实验性自身免疫性脑脊髓炎小鼠的磁共振研究

Study on MR examination of experimental autoimmune encephalomyelitis mice.

目的研究动物模型实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小 鼠中枢神经系统的MR表现。方法使用PLP139-151免疫接种雌性SJL／J小鼠诱导EAE。分别取复发期和缓解期 的EAE小鼠行脑和脊髓常规MR及Gd—DTPA增强MR扫描,并做组织病理学检查。结果PLP139-151能较好的诱 导出慢性复发-缓解型EAE模型,Gd-DTPA增强MR检查能充分显示血脑屏障的破坏,反映脑和脊髓的病灶,而且 显示的病灶相对信号强度复发期明显高于缓解期,在病灶处均可见炎症细胞浸润,髓鞘脱失,病灶周围或远离病灶 处炎症反应轻微。结论Gd—DTPA增强MR检查能准确反映血脑屏障的破坏,病变累及部位及病变程度,为今后使 用药物干预EAE判断疗效、指导进行较准确的病变部位取材时提供了一种更为客观的手段。

Objective To study MR characteristics of the central nervous system in experimental autoimmune encephalomyelitis mice Methods Experimental autoimmune encephalomyelitis （EAE） was induced by PLP139-151 in SJL/J mouse. EAE mice were seperately given routine Gd-DTPA enhanced MR examination in relapse and in remission stage. Part of the mice were scarificed for histopathological and immunohistochemical studies. Results A chronic relapsing form of EAE could be readily induced in SJL/J mouse with PLP139-151. Compromised blood-CNS barrier could be completely showed with Gd-DTPA enhanced MR examination. The focus in brain and spinal cord could also be displayed on T1 weighted imaging. The relative singal intensity was measured on the clearest scan in axleplane or coronal plane on T1 WI. The relative signal intensity of focus on T1 WI in replase was much higher than that in remission. There were significant histopathological changes corresponding to the focus, such as inflammatory cells infiltration and demyelination. There was mild inflammation around or away from the focus. Conclusions Gd - DTPA enhanced MR examination could exactly reflect the change of blood brain barrier permeability, sites of focus and the degree of histopathological changes. It provided an objective method in judging the therapeutic effect of some drugs and guided to accurately drawing materials from the focus.