猫急性脑静脉闭塞模型的MR扩散加权成像与病理学对照研究  

Evaluation of an acute experimental cerebral venous occlusion in cats with MR diffusion weighted imaging and histopathology

作　　者：查云飞[1] 孔祥泉[1] 徐海波[1] 冯敢生[1] 刘定西[1] 于群[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院放射科,武汉430022

出　　处：《中华放射学杂志》2005年第9期943-947,共5页Chinese Journal of Radiology

摘　　要：目的用MR扩散加权成像(DWI)和病理学方法对急性脑静脉闭塞动物模型进行评价.方法家猫22只,用随机数字表法分为2组(手术组18只,假手术组4只).采用开颅上矢状窦穿刺注射液体栓塞剂醋酸纤维素聚合物(CAP)联合双侧颈外静脉结扎制备急性脑静脉闭塞动物模型,在术后1、3、6、12、24、48 h用DWI、T2WI、液体衰减反转恢复序列(fluid attenuated inversion recovery, FLAIR)对模型行连续MR扫描,测量异常高信号最大层面相对面积(rs)比例、相对表观扩散系数(rADC)值,并和大体标本、光学显微镜及电子显微镜作对照研究.结果仅DWI能显示早期脑实质病变,3 h后,DWI、T2WI及FLAIR均能显示病变,24 h后,DWI呈高、等混杂信号改变.术后1 h,与对照组比较,rADC下降至(50.2±6.9)%,3～12 h间,rADC缓慢上升.平均上升速率每小时8.7%,12～24 h间,rADC又下降,平均下降速率每小时4.75%,24～48 h,rADC又缓慢上升至接近对照组的水平.1 h和48 h时间点,rADC差异有统计学意义(t=10.2335,P<0.01).大体病理学14只猫上矢状窦及桥静脉及皮层静脉内见CAP凝固呈铸型改变,12 h后窦旁皮层病变区被伊文思蓝不同程度蓝染.显微病理学见术后1～3 h以细胞内毒性水肿为主,3～24 h血管源性水肿逐渐出现并占优势,24～48 h出现出血性脑梗死.假手术组4只猫均未见上述各种异常表现. 结论 DWI能区分脑静脉闭塞后的脑水肿类型,早期评价脑组织损伤的程度.Objective To evaluate an acute experimental cerebral venous occlusion model in cats with DWI and histopathological study. Methods Twenty-two cats were randomly divided into 2 groups, including operation group （n = 18） and sham operation group （n =4）. Acute cerebral venous occlusion was induced by rostral and caudal injection of 0. 5 ml of the celhdose acetate polymer （CAP） solution into the superior sagittal sinus （SSS） and by immediate ligation of bilateral external jugular veins. DWI, T2WI, and FLAIR were continuously performed after the operation at an interval of 1, 3, 6, 12, 24, and 48 h, respectively （ n = 3 for each sub-group ）. The relative apparent diffusion coefficient （ rADC ） and relative area ratio （rs） of the biggest hyperintensity signal slice on MRI were measured. Macroscopic examination, lightscopy （hematoxylin-eosin staining）, and electron-microscopy were compared with MRI data. Results The early pathological changes were only detected with DWI （within lh） , and then the lesions were also detected with T2WI and FLAIR after 3 h. The lesions with hyperintensity and isointensity signal were observed on DWI after 24 h. The rADC value decreased quickly to （ 50.2 ± 6. 9 ） % of the control value at 1 h, then increased slowly at an average ascending velocity of 8.7%/h between 3 and 12 h, decreased again at an average descending velocity of 4.75%/h between 12 and 24, and increased slowly and approximinately equal to the control value after 24 h. The rADC value at 1 h showed significant difference with that at 48 h （ t = 10. 2335, P 〈 0. 01 ）. No abnormal changes were observed pathologically in 4 cats of sham operation group. There were castlike materials formed by CAP within SSS , bridging veins and cortical veins in 14 cats. The cortical lesions were stained with Evans blue dye after 12 h. The corresponding sequential pathologic changes were gradual increase of intracellular edama （ within 1 - 3 h ）, the emergence of vasogenic and cytotoxic edema （ 3

关 键 词：模型 动物 脑静脉 磁共振成像 病理学 MR扩散加权成像 脑静脉闭塞 显微病理学 动物模型 对照研究 家猫 

分 类 号：R445.2[医药卫生—影像医学与核医学]