磁共振T2-mapping定量成像评估兔急性肠系膜上动脉缺血小肠肠壁损伤的实验研究  

Experimental study on the evaluation of acute mesenteric artery ischemia in the small intestine wall injury of rabbits by quantitative magnetic resonance T2‐mapping technique

作　　者：陈梦莎 祖涵瑜 钟晓飞 李敏敏[1] 曹璋[2] 韩慧婷 曹赫 姜兴岳[1] CHEN Mengsha;ZU Hanyu;ZHONG Xiaofei;LI Minmin;CAO Zhang;HAN Huiting;CAO He;JIANG Xingyue(Department of Radiology,Affiliated Hospital of Binzhou Medical University,Binzhou 256603;Department of Pathology,Affiliated Hospital of Binzhou Medical University,Binzhou 256603)

机构地区：[1]滨州医学院附属医院放射科,滨州256603 [2]滨州医学院附属医院病理科,滨州256603

出　　处：《磁共振成像》2022年第9期69-74,80,共7页Chinese Journal of Magnetic Resonance Imaging

基　　金：山东省自然科学基金(编号:ZR2018LH015)。

摘　　要：目的探讨MRI T2-mapping定量成像对监测和评估兔小肠急性肠系膜上动脉缺血(acute mesenteric ischemia,AMI)肠壁损伤的诊断价值。材料与方法将36只新西兰雄性白兔随机分为实验组(n=18)和对照组(n=18)。实验组行外科手术结扎第2~5支肠系膜动脉弧形血管网以及相应肠管两端供血血管,随后分别于6个时间点(1 h、2 h、3 h、4 h、5 h、6 h)进行MR T2-mapping成像,每个时间点3只。扫描完成后分别对3只兔施行安乐死,取出肠系膜动脉弧形血管网第3分支所供应的肠管病理标本,评估小肠肠壁缺血损伤的严重程度和病理特征变化。对照组进行假手术,开腹不做结扎处理。各个时间点实验组与对照组定量数值的差异采用独立样本t检验,两组各时间点T2值的组内比较采用单因素方差分析,用高斯拟合模型对T2值与缺血时间点进行拟合,显示小肠缺血肠壁的演变规律,并用病理组织学进行相关验证。T2值与缺血时间点间的拟合方程为f(x)=145×exp{-[(x-3.475)/4.297]^(2)},拟合系数R^(2)=0.79。结果实验组6个时间点的T2值均高于对照组,差异有统计学意义(P<0.05)。实验组中T2_(3h)与T2_(1h)、T2_(2h)、T2_(5h)、T2_(6h)差异有统计学意义(P<0.05)。随着缺血时间的进展,T2值先升高后降低,前3 h病理表现以水肿炎细胞浸润为主,影像上缺血近3 h时的T2_(3h)值达到峰值(151.50±2.90)ms;缺血4 h时肠壁损伤到达肌层,此时出血面积大大增加,T2_(4h)值降为(142.50±4.30)ms,此后T2值持续降低。结论MRI T2-mapping定量成像有助于定量评估AMI小肠肠壁损伤,对于疾病的早期发现具有一定的优势,具有良好的临床应用前景。Objective:To explore the diagnostic value of T2‐mapping in quantitatively monitoring and assessing dynamic small intestine wall injury after acute mesenteric artery ischemia(AMI)in a rabbit model by MRI.Materials and Methods:Thirty-six New Zealand white rabbits were randomly divided into two groups.The experimental group performed surgical ligation of the arc-shaped vascular network of the 2nd-5th mesenteric artery and the blood supply vessels at both ends of the corresponding intestinal tract,followed by MR T2‐mapping imaging at 6 time points(1 h,2 h,3 h,4 h,5 h,6 h),3 rabbits at each time point.After scanning,3 rabbits were euthanized,and the intestinal pathological specimens supplied by the third branch of the mesenteric artery arc vascular network were taken out to evaluate the severity of ischemic damage to the small intestinal wall and the changes in pathological characteristics.The control group underwent sham operation without ligation.The differences between the quantitative values of the experimental group and the control group at each time point were performed by independent samples t test,and the intra-group comparison of T2 values at each time point between the two groups was performed by one-way analysis of variance.A Gaussian fitting model was used to fit the T2 value to the ischemic time point to show the evolution of the ischemic intestinal wall in the small intestine,which was verified by histopathology.The fitting equation between T2 value and ischemic time point is f(x)=145×exp{-[(x-3.475)/4.297]^(2)},and the fitting coefficient R^(2)=0.79.Results:The T2 values of the experimental group at 6 time points were higher than those of the control group,and the difference was statistically significant(P<0.05).There were statistical differences between T2_(3h) and T2_(1h),T2_(2h),T2_(5h) and T2_(6h) in the experimental group(P<0.05).With the progression of ischemia time,the T2 value first increased and then decreased.The pathological manifestations in the first 3 hours were mainly edema and infil

关 键 词：T2-mapping 定量技术 磁共振成像 急性肠系膜缺血 新西兰兔模型 小肠肠壁损伤 

分 类 号：R445.2[医药卫生—影像医学与核医学] R-332[医药卫生—诊断学]