弥散加权成像诊断兔急性肝缺血再灌注损伤  

Diffusion weighted imaging assessment of acute hepatic ischemia reperfusion injury in rabbit models

作　　者：郭成伟[1,2] 易贤林[2] 罗维[1] 曾琼新[1] 曹希明[1] 梁长虹[1] 

机构地区：[1]广东省医学科学院广东省人民医院放射科,广东广州510080 [2]南方医科大学研究生学院,广东广州510515

出　　处：《中国医学影像技术》2011年第7期1321-1324,共4页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金(30800269;30970798);广东省科技计划基金(2005B10401040);广东省自然科学基金(5001199)

摘　　要：目的探讨3.0T MR DWI对兔急性肝脏缺血再灌注损伤(IRI)的诊断价值。方法新西兰大白兔24只,将其中18只兔制成IRI模型,结扎肝左叶血供60 min后恢复血供,随机分为0.5 h、2 h和6 h组,每组6只;另外6只作为对照组,仅解剖肝十二指肠韧带,未阻断血供。b值分别选取100、200、300、500、600 s/mm2,行T2W、T1W、增强T1W检查,并进行组织病理学检查。结果 IRI后0.5 h,T2 WI和DWI表现为整个肝左叶信号增高,在2 h和6 h时出现点片状高信号以及相对应的强化减低区。b=100、200、300 s/mm2时,0.5 h组ADC值明显低于对照组(P<0.05);2 h组ADC值虽有升高(b≤300 s/mm2较明显),但与对照组间差异无统计学意义(P>0.05);b=100 s/mm2时,6 h组与对照组间差异有统计学意义(P<0.05)。镜下表现:IRI早期肝细胞弥漫性肿胀、肝窦内、中央静脉及小动脉内大量红细胞淤积。随着损伤加重,肝窦及肝实质内中性粒细胞浸润,肝细胞核固缩凋亡,肝窦解离。结论应用较小b值(b≤300 mm2/s),3.0T DWI能反映兔肝脏IRI早期阶段的肝血窦淤血等微循环障碍的病理生理过程,对于早期动态监测、预防肝脏IRI具有重要临床意义。Objective To explore the value of DWI in assessment of acute hepatic ischemia reperfusion injury （IRI） in rabbit models. Methods IRI models were established in 18 New Zealand white rabbits. The rabbit models were then divided into three groups （including 0.5 h, 2 h and 6 h group, each n=6）, undergoing 60 min＇s left lobar ischemia and following 0.5, 2 and 6 h reperfusion. The rest 6 rabbits were taken as control group without liver ischemia-inducing. DWI using b values of 100, 200, 300, 500 and 600 s/mm2 was performed with a 3.0T clinical MR scanner in all rabbits to obtain T2WI, TIWI and contrast-enhanced TIWI, respectively. Liver histopathology at different time points were also examined. Results On T2WI and DWI, the signal of the left lobar in 0.5 group increased obviously. With progressive of IRI, the affected liver appeared uneven spots higher signal （T2WI, DWI） and showed relatively low strengthening regions at the 2 h and 6 h groups. The ADC of 0. 5 h group was significantly lower than that of control group （P〈0.05） while b values were 100, 200, and 300 s/mm2. The ADC of 2 h group increased immediately compared with that of the control group, especially when b values 4300 s/mm^2 , but there was no statistical difference between control group and other groups （P〉0.05）. There was significantly difference between control group and 6 h group when b value was 100 s/mm^2 （P〈0.05）. Liver histology showed diffuse hepatocytes swelling and much of erythrocytes deposited in hepatic sinusoids, portal area, and central venous and arterial at the initial phase. With the injury aggravated, inflammatory cell aggregated in the hepatic microvasculature, and hepatic parenchyma, hepatocyte nuclear condensation of apoptosis and sinusoidal dissociation. Conclusion 3.0T DWI can monitor the pathological process of rabbit hepatic IRI dynamically in particular at early stages, and reflect the microvaseular disorder and other histopathological changes with smaller b values （≤4300 s/mm^2 ）.

关 键 词：肝脏 扩散磁共振成像 再灌注损伤 

分 类 号：R332[医药卫生—人体生理学] R445.2[医药卫生—基础医学]