临床型MR观察多发性硬化模型大鼠中枢神经系统

MRI of the central nervous system in rats of multiple sclerosis with clinical whole body MR scanner

目的探索临床型MR扫描仪配备临床应用型线圈进行多发性硬化(MS)模型大鼠脑和脊髓病灶成像研究的可行性。方法选用髓鞘少突胶质细胞糖蛋白多肽35～55致敏Lewis大鼠制备MS模型动物10只。以1.5TMR扫描仪配用小肢端表面柔线圈,分别对大鼠脑和脊髓行T1WI和T2WI扫描,层厚1～2mm;以3.0TMR扫描仪配用正交腕关节线圈,分别对大鼠脑和脊髓行T1WI、T2WI和Gd-DTPA增强T1WI三维容积扫描,体素0.06～0.08mm3。利用工作站专业软件获得脑和脊髓多方向重组图像。结果3.0TMRT2WI和T1WI显示MS大鼠脑内病灶具有较高的空间分辨力和对比度,脊髓病灶的对比度较弱。1.5TMR设备显示大鼠MS病灶的空间分辨力较低。MS模型大鼠的中枢神经系统病灶分布在脑和脊髓,斑片状,呈T2高信号、T1低信号,Gd-DTPA增强后部分病灶强化。结论临床型3.0TMR设备能清晰显示MS模型大鼠脑以及脊髓内部的病灶,为小动物中枢神经系统疾病的实验研究提供了一种能广泛应用的无创性手段。

Objective To explore the feasibility of using clinical whole body MR scanners to investigate the intravital visibility of central nervous system （CNS） lesions in rats of multiple sclerosis （MS）. Methods Ten Lewis rats were injected with the peptide 35--55 of myelin oligodendrocyte glycoprotein to make the model of MS. On a Siemens Sonata 1.5T MR scanner equipped with a flexible surface coil, rats brain and spinal cord were examined using T2-weighted and T1-weighted imaging with slice thickness of 1--2 ram. On a Siemens Trio Tim 3.0T MR-scanner equipped with a quadrature wrist coil, rats were examined using T2WI, TIWI and Gd-DTPA enhanced T1WI 3-dimensional imaging with voxel size up to 0. 06-- 0.08 mm^3. Rat brain and spinal cord images in multiple orientations were reconstituted with special software in workstation. Results T2WI and TIWI of the lesions in MS rat brain wi.th high spatial and contrast resolution could be obtained with clinical 3.0T MR scanner, though the image resolution of spinal cord was relatively low. The resolution of 1.5T MR was lower than that of 3.0T. Plaques in CNS of MS rats presented as hyperintense areas on T2WI and hypointense areas on T1WI. Contrast enhancement was observed as hyperintense on T1WI. Conclusion High quality images of CNS lesions canbe obtained with clinical 3.0T MR-scanner in MS rat, which offers a noninvasive access for studying CNS diseases in the rats.