肠系膜上动脉压迫综合征合并胡桃夹综合征的CT血管造影征象分析

Computed tomography angiography characteristics of superior mesenteric artery syndrome complicated by nutcracker syndrome

目的分析肠系膜上动脉压迫综合征(SMACS)合并胡桃夹综合征(NCS)的CT血管造影征象,探讨其临床诊断价值。方法随机抽取2017年6月至2019年6月郑州大学第一附属医院收治的行CT血管造影检查的SMACS合并NCS患者108例为病变组,另随机抽取同期行CT血管造影检查SMACS、NCS症状阴性者108例为正常组。在VR像上分别测量腹主动脉(AA)与肠系膜上动脉(SMA)夹角,在轴位图像上左肾静脉通过SMA与AA夹角层面测量左肾静脉内径(a)及SMA与AA距离(D1),在肾门层面肾静脉最宽处测量左肾静脉内径(b),计算b/a比值,在十二指肠通过SMA与AA夹角层面测量SMA与AA距离(D2)。建立受试者工作特征曲线(ROC),计算诊断临界值及其敏感性、特异性。结果AA与SMA夹角、a、D1、D2均为正常组大于病变组,差异有统计学意义(t=12.432、3.554、12.864、13.330,P=0.000、0.001、0.000、0.000);b、b/a均为正常组小于病变组,差异有统计学意义(t=-2.910、-7.975,P=0.005、0.000)。AA与SMA夹角、a、D1、D2该四项指标的ROC曲线下面积分别为0.998、0.904、0.999、0.994,诊断临界值分别为34.05°、3.45 mm、5.07 mm、6.93 mm,敏感度分别为92.7%、92.7%、100%、97.6%,特异度分别为96.2%、77.4%、98.1%、98.1%。结论CT血管造影可直观反映AA与SMA夹角、AA与SMA距离、左肾静脉内径及其与十二指肠受压情况,对SMACS合并NCSD的诊断有实际应用价值。

Objective To analyze the computed tomography (CT) angiography characteristics of superior mesenteric artery syndrome(SMACS)complicated by nutcracker syndrome(NCS), and to investigate the diagnostic value.Methods A total of 108 patients with SMACS complicated by NCS who underwent CT angiography from June 2017 to June 2019 in the First Affiliated Hospital of Zhengzhou University were randomly selected as lesion group, and 108 normal patients were selected as normal group.The angle between the superior mesenteric artery (SMA) and the abdominal aorta (AA) were measured on virtual reality imaging, inner diameter of stenosis (a)and renal hilum (b)of the left renal vein was measured on enhanced CT. The inner diameter ratio between the b and a were calculated, the distances between SMA and AA were measured in the left renal vein and duodenum through SMA and AA levels(D1, D2). Receiver operator characteristic curve (ROC) was established to calculate the cut-off value and to evaluate the sensitivity, specificity of these parameters.Results The angles between AA and SMA, and length of a, D1 and D2 of the normal group were all larger than those of the lesion group, and the differences were significant (t=12.432, 3.554, 12.864, 13.330;P=0.000, 0.001, 0.000, 0.000);b, b/a of the normal group were smaller than that of the lesion group, the differences were significant (t=-2.910, -7.975;P=0.005, 0.000). The area under the ROC of the SMA-aortic angle, the value of a, D1 and D2 were 0.998, 0.904, 0.999 and 0.994 respectively with corresponding cut-off values of 34.05°, 3.45 mm, 5.07 mm, and 6.93 mm, sensitivity of 92.7%, 92.7%, 100% and 97.6%, specificity of 96.2%, 77.4%, 98.1% and 98.1%, respectively.Conclusions CT angiog raphy can directly reflect the angle between AA and SMA, the distances between SMA and AA, the inner diameter of left renal vein and narrowing of the third part of the duodenum, and provide effective information for the diagnosis of NCS complicated with SMACS.