摘要
目的:通过对大鼠肝右叶坏死和凋亡的动物模型进行磁共振T1WI、T2WI、DWI和ADC等检查,观察形态和信号变化特点,探索MRI新技术对肝脏组织坏死或凋亡的鉴别诊断能力。材料和方法:78只大白鼠随机分成13组,每组6只,A1、B1、C1、D1、E1、F1六组动物同时结扎肝动脉右支和门静脉右支。A2、B2、C2、D2、E2、F2六组动物单独结扎门静脉右支,另6只大鼠为假手术对照组。各组实验大鼠于手术后3h、12h、24h、3d、7d、14d进行MRI检查,然后处死动物并取得肝脏标本,进行HE染色、TUNEL染色、透视电镜等病理检查。每例均进行常规MRI和DWI、ADC图成像。结果:动物麻醉和结扎手术成功率93.8%。右侧肝动脉与门静脉分支均结扎后,病理显示肝右叶发生凝固性坏死。单独右侧门静脉分支结扎后,3h即出现凋亡细胞,24h达高峰。坏死肝组织在DWI上早期即呈高信号,中晚期呈长T1和中等T2表现。单纯门静脉右支结扎的A2、B2、C2组大鼠肝右叶在T1WI上呈特征性较高信号,T2WI呈等信号,72h后出现斑点状高信号,DWI上早期呈信号减低改变,后期呈等信号或小片状高信号。结论:肝组织细胞坏死和凋亡在T1WI和T2WI上有明显的信号差异表现。结合DWI和ADC检查表现,可以区分肝脏细胞发生坏死或凋亡的不同病理改变。
A series of advanced MRI sequences including T1WI, T2WI, DWI, and ADC mapping were conducted on rat models of hepatic necrosis and apoptosis. The morphological appearances and signal characteristics were collected to demonstrate the diagnostic ability and the differential features of the advanced MRI technology for hepatic necrosis and apoptosis. Materials and Methods： Seventy - eight rats were randomly divided into 13 groups, 6 rats in each group. Rats in group A1, B1, C1, D1, E1,. F1 were enrolled for the groups of hepatic necrosis where both right hepatic and portal vein were ligated. Rats in group A2, B2, C2, D2, E2, F2 for hepatic apoptosis by ligating only the right portal vein. Six rats were sham - operated for control study. Rats in group A（including A1 and A2）, B, C, D, E, F were exmanined at 3h, 12h, 24 h, 3d, 7d, 14d after the surgical operation of ligation. The rats were sacrificed immediately after MRI examination and the hepatic tissue was harvested. The hepatic samples were further examined by HE stain, TUNEL stain, Envision PCNA stain, and electronic microscopy. For each rat, conventional axial T1WI, T2WI, coronal T2WI sequences were conducted initially, followed by ADC mapping and DWI imaging. Results： The success rate of anesthesia and surgery is 93.8%. Pathological studies showed hepatic coagulative necrosis after the ligation of both right hepatic artery and portal vein. When only right portal vein was ligated, apoptosis process can be seen at 3 hrs after the surgery, with a peak at 24th hour. In the group of hepatic necrosis, DWI showed a significant high signal right lobe at early stage.On conventional images of T1WI, T2WI, the right lobe was long T1 andlong T2 manifestations. Distinguishing high signal intensities on TI WI were observed in the right lobes of the rats in group A2, B2, C2. No signal changes were seen on T2WI, Blotch or patchy high signal was revealed on T2WI in group D2 and E2. On DWI, right lobes were low signal intensity in early stage and iso - density or spot high signal intensity after 3d, Conclusion： There were significant different signal changes on conventional TIWI and T2 WI on the groups of necrosis and apoptosis, Combined with the findings on DWI and ADC mapping, it is possible and practical to detect and differentiate the two pathological processes： hepatic necrosis and apoptosis,
出处
《中国医学计算机成像杂志》
CSCD
2006年第2期99-104,共6页
Chinese Computed Medical Imaging
基金
(上海市自然科学基金项目
编号02ZB14103)
关键词
磁共振成像
弥散成像
肝组织坏死
肝组织凋亡
Liver Necrosis Apoptosis Magnetic resonance imaging Diffusion weighted imaging
