双能量CT的不同定量参数在直肠癌术前评估中的应用价值

Application Value of Different Quantitative Parameters of Dual Energy CT in Preoperative Rectal Cancer

目的探讨双能量CT的不同定量参数在直肠癌患者术前评估中的诊断价值。方法回顾性搜集118例直肠癌患者,术前均行双能量CT扫描。根据病理,分为无淋巴结转移组和有淋巴结转移组、癌结节组和无癌结节组、脉管神经侵犯组和无脉管神经侵犯组。比较不同分组在动静脉期的对比剂含量、碘浓度(IC)、标准化碘浓度(nIC)、电子云密度(Rho)、原子序数(Z)、双能量指数(DEI)、能谱曲线斜率(K)的差异。绘制受试者工作特征(ROC)曲线,比较曲线下面积(AUC),明确诊断效能。结果定量参数的组间一致性为0.803~0.928。无淋巴结转移组的静脉期nIC明显低于有淋巴结转移组(P<0.001,AUC=0.771)。无癌结节组的静脉期Rho高于癌结节组(P=0.037,AUC=0.635)。无脉管神经侵犯组的动脉期Rho高于脉管神经侵犯组(P=0.025,AUC=0.648)。结论双能量CT的不同定量参数可用于评估直肠癌患者术前的淋巴结状态、癌结节和脉管神经侵犯情况,为直肠癌患者精准化治疗提供有效依据。

Objective To investigate the application value of different quantitative parameters of dual energy CT in patients with rectal cancer.Methods 118 patients with rectal cancer were enrolled retrospectively.All patients were performed dual energy CT.According to pathological results,the patients were divided into lymph node metastasis negative and positive groups,tumor depositnegative and positive groups,lymphovascular or perineurium invasionnegative and positive groups.Dual energy parameters including dual-phase CT value,iodine concentration(IC),normalized iodine concentration(nIC)、the electron density(Rho),effective atomic number(Z),dual energy index(DEI)and K were analyzed in different groups.The receiver operating characteristic(ROC)curve was analyzed,and the area under the ROC curve(AUC)was calculated to evaluate the diagnostic performance.Results Interobserver agreement were 0.803-0.928 for parameters.The mean values of nIC in venous phase in lymph node metastasis negative group were smaller than that in lymph node metastasis positive group(P<0.001,AUC=0.771).The mean values of Rho in venous phase intumor deposit negative group was higher than that in tumor deposit positive group(P=0.037,AUC=0.635).The mean values of Rho in arterial phase in lymphovascular or perineurium invasion negative group was higher than that in lymphovascular or perineurium invasion positive group(P=0.025,AUC=0.648).Conclusion Different quantitative parameters of dual energy CT can be used to evaluate lymph nodes metastasis,tumor deposit and lymphovascularor perineurium invasionin rectal cancer and provide effective basis for precision therapy of patients with rectal cancer.