猪小肠缺血再灌注损伤的多层螺旋CT灌注成像研究

Research on Multi-Slice Spiral CT Perfusion Imaging in Porcine Models with Small Intestinal Ischemia-Reperfusion Injury

目的:探讨多层螺旋CT(multi-slice CT,MSCT)灌注成像评价猪小肠缺血再灌注损伤(ischemia-reperfusion injury,IRI)的价值。方法:将48只巴马猪随机分为IRI组、假手术组(sham组)和单纯缺血组。IRI组在夹闭肠系膜上动脉(superior mesenteric artery,SMA)主干2 h后松开,分别再灌注1 h、2 h、3 h和4 h;sham组仅分离SMA主干而不夹闭;单纯缺血组夹闭SMA2 h,不进行再灌注。造模结束后行MSCT灌注扫描,扫描结束取远端回肠黏膜标本,测定丙二醛(malondialdehyde,MDA)含量、超氧化物歧化酶(superoxide dismutase,SOD)活性,评价病理损伤。比较各组灌注参数差异,以及灌注参数与MDA和SOD的相关性。结果:IRI组不同时间点血容量、血流量、平均通过时间和表面通透性与sham组比较,差异均有统计学意义(P<0.05);IRI组不同时间点间血流量、血容量、表面通透性比较,差异均有统计学意义(P<0.01)。血流量和血容量与MDA呈负相关(r=-0.714、-0.713,P<0.01),与SOD值呈正相关(r=0.641、0.677,P<0.01)。结论:MSCT灌注成像能够反映小肠IRI及其动态演变过程,与生化标志物具有良好的相关性,是评价小肠IRI的有效方法。

Objective：To investigate the value of multi-slice spiral CT（MSCT）perfusion imaging in evaluating small intestinal ischemia-reperfusion injury（IRI）of porcine models.Methods：A total of 48 bama minipigs were randomly divided into IRI group,sham-operated group and ischemic group.In IRI group,the superior mesenteric artery（SMA）was clamped for 2 h,followed by reperfusion for 1 h,2 h,3 h,4 h,repectively.SMA was separated in sham-operated group without clamping.SMA in ischemic group was clamped for 2 h without reperfusion.Once models built,small intestinal MSCT perfusion imaging was performed.The malondialdehyde（MDA）concentration and superoxide dismutase（SOD）activity of mucosal specimens from distal ileum were detected,and the histopathologic damage were evaluated.The difference of perfusion parameters among groups and the correlation of perfusion parameters with MDA and SOD were evaluated.Results：The differences in blood flows（BF）and blood volume（BV）,mean transit time（MTT）and permeability surface（PS）at different time points between IRI group and sham-operated group were statistically significant（P〈0.05）.There were significant differences in BF,BV and PS of IRI group among different time points（P〈0.01）.BF and BV were negatively correlated to MDA（r=-0.714,-0.713,P〈0.01）,but positively correlated to SOD（r=0.641,0.677,P〈0.01）.Conclusions：MSCT perfusion imaging can reflect the small intestinal IRI and its dynamic evolution process.It has certain correlations with biochemical markers and is the effective method for evaluating small intestinal IRI.