单源双能CT能谱曲线鉴别不同病理级别膀胱尿路上皮癌的价值

The value of spectral curve in the differential diagnosis of urothelial carcinoma of the bladder with different pathological grades

目的 探讨单源双能CT能谱曲线特征对不同病理级别膀胱尿路上皮癌(UCB)的鉴别诊断价值.方法 回顾性分析经手术病理证实且术前行盆腔单源双能CT能谱成像检查的55例单发UCB病人资料,其中男47例,女8例,年龄47~97岁,中位年龄72岁.依据病理诊断结果 分为高级别UCB(HGUCB)组(32例)和低级别UCB(LGUCB)组(23例).采用能谱扫描模式进行平扫及3期动态增强扫描.由2名观察者分别测量2组病灶平扫及动、静脉期各单能量CT值,生成能谱曲线,并计算曲线斜率(K).采用组内相关系数(ICC)检验2位观察者测量各期数据结果 的一致性,采用独立样本t检验分析2组病灶平扫及增强动、 静脉期各参数的差异.采用受试者操作特征(ROC)曲线分析差异有统计学意义参数的诊断效能.结果 平扫,动、静脉期中2位观察者测量高低级别病灶的各单能量CT值的一致性均良好(均ICC>0.75).动脉期HGUCB组40~100 keV单能量CT值均高于LGUCB组(均P<0.05);平扫及静脉期2组病灶40~140 keV各单能量CT值以及动脉期110~140 keV单能量CT值差异均无统计学意义(均P>0.05).动脉期HGUCB组的K值高于LGUCB组(P<0.05);2组平扫及静脉期的K值差异均无统计学意义(均P>0.05).动脉期K值诊断HGUCB的ROC曲线下面积(AUC)为0.754(95%CI:0.625~0.883),敏感度和特异度分别为60.9%和84.4%.动脉期单能量CT值中,40 keV诊断HGUCB的效能最大,AUC为0.787(95%CI:0.665~0.908),敏感度和特异度分别为68.8%和78.3%.结论 单源双能CT能谱成像动脉期能谱曲线可鉴别不同病理级别UCB,并具有一定临床应用价值.

Objective To investigate the value of spectral curves of the single-source dual-energy spectral CT in differentiating different histopathological grades of urothelial carcinoma of the bladder(UCB).Methods Fifty-five patients(47 males and 8 females,age 47-97 years,median age 72 years)who had histopathologically proven single nodule UCB and had undergone pelvic single-source dual-energy CT scan were retrospectively analyzed.Lesions were divided into two groups according to histopathological results,high grade UBC(HGUCB)group contained 32 cases,and low grade UCB(LGUCB)group contained 23 cases.The spectrum scanning mode was applied for non-enhanced and 3 dynamic enhanced phases.The single-energy CT values of lesions in the non-enhanced,arterial,and venous phases were measured by two observers,then the spectrum curve was generated,and the slope(K)of the curve was calculated.The intra-class correlation coefficients(ICCs)were used to check the consistency of the data measured by the two observers.All the above parameters were compared between the two groups with t-test,and the reciever operating charaeteristics(ROC)curve was used to evaluate the diagnostic efficacy of these parameters.Results The consistency of the data measured by the two observers were good(all ICC value>0.75).In the arterial phase,the single-energy CT values on 40-100 keV of group HGUCB were higher than that of group LGUCB(P<0.05).There were no significantly differences of the single-energy CT values among the 40-140 keV in the non-enhanced phase,venous phase,and the 110-140 keV single-energy CT values in the arterial phase between the two groups(P>0.05).The K value of group HGUCB was higher than that of group LGUCB in the arterial phase(P>0.05);there was no significantly differences of K values in the non-enhanced and venous phases between the two groups(P>0.05).Among above parameters,the areaunder the curve(AUC)of the spectral curve slop diagnosing HGUCB was 0.754(95%CI:0.625-0.883),which yielded sensitivity of 60.9%and specificity of 84.4%.Among the single-energy CT values of arterial phase,CT value measured on 40 keV images yielded the highest efficacy in diagnosing HGUCB,with AUC of 0.787(95%CI:0.665-0.908),sensitivity and specificity of 68.8%and 78.3%,respectively.Conclusion The arterial phase spectral curve of single-souse dual-energy CT can identify different pathological grades of UCB,which provides clinical application values.