能谱CT在不典型结核球与肺癌中的诊断价值

目的 探讨能谱CT在不典型结核球与肺癌中的鉴别诊断价值.方法 对45例肺结节或肿块患者进行能谱平扫及2期增强扫描,所有病灶均经病理证实.选取平扫、动脉期及静脉期能谱图像对不典型结核球组与肺癌组进行分析,测量、计算感兴趣区的标准化碘浓度(NIC)、能谱衰减曲线斜率(λHU)、平扫及2期增强扫描CT值.用两独立样本t检验分析2组病灶各能谱参数的差异.生成受试者工作特性(ROC)曲线,并比较各参数的灵敏度和特异度.结果 45例患者中,不典型结核球11例,肺癌34例.比较2组的NIC、两期增强λHU和70 keV单能量图像净增CT值,肺癌组均高于不典型结核球组,差异有统计学意义(P<0.05);而2组平扫CT值差异无统计学意义(P>0.05).当NIC诊断阈值为0.105时,约登指数最大(0.733),ROC曲线下面积(AUC)为0.89,灵敏度和特异度分别为82.4%和90.9%.结论 能谱CT各参数有助于不典型结核球与肺癌的鉴别诊断,尤其是NIC值诊断价值较高.

The diagnostic value of spectral CT in atypical tuberculosis ball and lung cancer

Objective To study the diagnostic value of spectral CT in atypical tuberculosis ball and lung cancer.Methods 45 cases of pulmonary nodule or mass received unenhanced and two phase enhanced scan in gemstone spectral imaging mode,and all pulmonary nodule or mass were confirmed by pathology.Selecting unenhanced,arterial phase and venous phases of spectrum image,atypical tuberculosis ball group and lung cancer group were analyzed.Normalized iodine concentration (NIC), the spectral curve slope (λHU),CT value of unenhanced and two phase enhanced spectrum image were measured and calculated.Two independent samples t-test was used for the statistic analysis of each spectrum parameters between the two groups.The receiver operating characteristic (ROC) curve was obtained for comparing the sensitivity and specificity of each spectral parameter.Results Among the 45 patients,11 were atypical tuberculosis ball, and 34 were lung cancer.Comparison NIC,two phase enhanced λHU and the net enhanced CT values of 70 keV monoenergetic image of the two groups, lung cancer group was higher than atypical tuberculosis ball group,and the difference was statistically significant(P<0.05);However, the unenhanced CT value of 70 keV monoenergetic image of the two groups was not statistically significant (P>0.05).When the NIC diagnostic threshold was 0.105, the maximum Youden index (0.733), the area under the ROC curve was 0.89, and sensitivity and specificity was 82.4% and 90.9%, respectively.Conclusion The quantitative parameters of spectral CT is helpful in the diagnosis of atypical tuberculosis ball and lung cancer,especially the NIC with high value.