基于双能量CT中双能量指数、原子序数结合能谱曲线斜率对于鉴别泌尿系结石成分的价值研究

Study on the value of dual energy index and atomic number combined with slope of energy spectrum curve in identifying components of urinary tract stones based on dual energy CT

目的:评估双能量计算机体层扫描(DECT)的双能量指数(DEI)、有效原子序数(Zeff)结合能谱曲线斜率在鉴别患者泌尿系结石成分的价值。方法:收集2019年10月至2022年10月在南通市海门区人民医院就诊的111例泌尿系结石患者的临床及DECT影像资料。所有患者泌尿系结石直径均>5 mm,所有患者的离体结石均经红外光谱分析确定结石成分。分别计算DEI、Zeff、能谱曲线斜率及三者结合对于鉴别泌尿系结石成分的准确率、灵敏度、特异度等。结果:111例患者中草酸钙结石75例(占67.57%),羟基磷灰石15例(占13.51%),尿酸结石21例(占18.92%),未发现胱氨酸等其他类型结石。3种类型结石的CT值(F=487.691,P<0.001)、DEI(F=395.553,P<0.001)、Zeff(F=818.689,P<0.001)和能谱曲线斜率(H=19.615,P<0.001)比较的差异均有统计学意义。DEI、Zeff和能谱曲线斜率对鉴别泌尿系结石成分的总准确率分别为87.39%(97/111)、84.68%(94/111)和81.98%(91/111)。DEI、Zeff和能谱曲线分别对草酸钙结石、羟基磷灰石及尿酸结石诊断准确率均为80%~100%。DEI、Zeff结合能谱曲线斜率对鉴别泌尿系结石成分的总准确率为94.59%(105/111)。DEI、Zeff结合能谱曲线斜率对草酸钙结石、羟基磷灰石及尿酸结石诊断的准确性分别为94.59%、94.59%和100%。结论:与DECT的单个指标相比,DEI、Zeff结合能谱曲线斜率对鉴别泌尿系结石成分显示出更好的诊断准确率。

Objective:To assess a value of dual energy index(DEI)and effective atomic number(Zeff)of dual-energy computed tomography(DECT)combined with slope of energy spectrum curve in identifying the component of urinary tract stones.Methods:The clinical and DECT imaging data of 111 patients with urinary tract stones who admitted to Nantong Haimen People′s Hospital from October 2019 to October 2022 were selected,and the diameters of the urinary tract stones of all patients were<5 mm.The components of outside body stones of all patients were analyzed by infrared spectrum.The accuracy,sensitivity and specificity of the DEI,Zeff,slope of energy spectrum curve and the combination of the them were respectively calculated in identifying the components of urinary tract stones.Results:In 111 patients,the patients with calcium oxalate stones were 75(67.57%),and ones with hydroxyapatite were 15 cases(13.51%),and ones with uric acid stones were 21 cases(18.92%),and there were no other type of stone included cysteine.The differences of CT values(F=487.691,P<0.001),DEI values(F=395.553,P<0.001),Zeff values(F=818.689,P<0.001)and the slopes of energy spectrum curves(H=19.615,P<0.001)were statistically significant among the three types of stones.The overall accuracies of DEI,Zeff and slope of energy spectrum curve were 87.39%(97/111),84.68%%(94/111)and 81.98%(91/111)in identifying the components of urinary tract stone.The range of diagnostic accuracies of DEI,Zeff and the slope of energy spectrum curve was between 80%and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.The overall accuracy of DEI,Zeff combined with slope of energy spectrum curve was 94.59%(105/111)in identifying the components of urinary tract stones.The diagnostic accuracies of DEI,Zeff combined with slope of energy spectrum curve were respectively 94.59%,94.59 and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.Conclusion:Compared with the single indicator of DECT,the DEI and Zeff combined with the slope of the energy spectrum curve showed better diagnostic accuracy in identifying the components urinary track stones.