能谱CT参数在膀胱尿路上皮癌术前病理分级预测中的价值

The value of energy spectrum CT parameters in predicting preoperative pathological grade of bladder urothelial carcinoma

目的:探讨能谱CT参数在术前预测膀胱尿路上皮癌病理分级中的价值。方法:回顾性分析60例经手术病理证实并行病理分级的膀胱尿路上皮癌患者的病例资料,其中低级别(LGUC)32例,高级别(HGUC)28例。所有患者均行平扫、动脉期及静脉期增强能谱CT扫描,分别获得动脉期和静脉期70 keV单能量CT值、碘浓度(IC)、水浓度(WC)、有效原子序数和能谱曲线斜率(λ值),对比分析两组肿瘤患者CT定性征象及能谱CT定量参数间的差异,绘制受试者工作特征(ROC)曲线评估各参数的分级诊断效能。结果:CT定性征象中,LGUC和HGUC的钙化发生率分别为25.00%和57.14%,囊变坏死的发生率分别为12.50%和50.00%,壁外浸润的发生率分别为6.25%和28.57%,两组间差异均具有统计学意义(P<0.05)。能谱CT定量参数中,HGUC组的动脉期70 keV单能量CT值、有效原子序数、IC、λ值均高于LGUC,差异均有统计学意义(P<0.05);而两组间静脉期70 keV单能量CT值、IC、有效原子序数以及λ值差异均无统计学意义(P>0.05),动脉期及静脉期WC在两组间差异均无统计学意义(P>0.05)。ROC曲线分析结果显示各参数中动脉期λ值鉴别LGUC与HGUC的效能最佳,AUC值高达0.974,以动脉期λ值3.5为阈值时,其分级诊断的敏感度和特异度分别为92.90%和93.75%。结论:能谱CT参数有助于术前预测膀胱尿路上皮癌病理分级,可为患者手术方式制定及治疗方案选择提供更多参考信息。

Objective:To explore the value of energy spectrum CT parameters in the preoperative prediction of the pathological grade of bladder urothelial carcinoma.Methods:A total of 60 patients with pathologically confirmed bladder cancer were retrospectively analyzed.They were divided into low-grade bladder urothelial carcinoma(LGUC,n=32) and high-grade bladder urothelial carcinoma(HGUC,n=32) groups.All patients underwent a plain scan, arterial phase and venous phase scans in energy spectrum CT.CT value in 70keV mono-energetic images, iodine concentration(IC),water concentration(WC),effective atomic number and energy spectrum curve slope(λ) in the arterial phase and venous phase were obtained.The differences between the two groups were compared in terms of the qualitative CT characteristics and the quantitative CT parameters.The receiver operating characteristic(ROC) curve was drawn to evaluate the ability of parameters to predict the grade of bladder urothelial carcinoma.Results:Among the qualitative CT characteristics, the incidence of calcification was 25.00% and 57.14%,the incidence of cystic necrosis was 12.50% and 50.00%,and the incidence of extra-mural infiltration was 6.25% and 28.57% in the LGUC and HGUC groups, respectively(P<0.05).Among the quantitative CT parameters, the CT value in 70keV mono-energetic images, effective atomic number, IC and of HGUC in the arterial phase were higher than those of the LGUC group(P<0.05).The CT value in 70keV mono-energetic images, IC, effective atomic number and in the venous phase were not statistically different(P>0.05).There was no significant difference in WC between the arterial phase and venous phase(P>0.05).The ROC results showed that the in arterial phase was the best indicator to distinguish LGUC from HGUC,with an AUC value as high as 0.974.When the in arterial phase of 3.5 was used as the threshold, the sensitivity and specificity of classification were 92.9% and 93.75% respectively.Conclusions:Energy spectrum CT parameters have potential value in preoperative prediction of the pathological grade of bladder urothelial carcinoma.