The value of dual-energy spectral CT in differentiating solitary pulmonary tuberculosis and solitary lung adenocarcinoma

Background To explore the value of dual-energy spectral CT in distinguishing solitary pulmonary tuberculosis (SP-TB) from solitary lung adenocarcinoma (S-LUAD). Methods A total of 246 patients confirmed SP-TB (n = 86) or S-LUAD (n = 160) were retrospectively included. Spectral CT parameters include CT 40keV value, CT 70keV value, iodine concentration (IC), water concentration (WC), effective atomic number (Zeff), and spectral curve slope (λ 70keV ). Data were measured during the arterial phase (AP) and venous phase (VP). Chi-square test was used to compare categorical variables, Wilcoxon rank-sum test was used to compare continuous variables, and a two-sample t -test was used to compare spectral CT parameters. ROC curves were used to calculate diagnostic efficiency. Results There were significant differences in spectral CT quantitative parameters (including CT 40keV value [all P< 0.001] , CT 70keV value [all P< 0.001], λ 70keV [ P< 0.001, and P = 0.027], Zeff [ P = 0.015, and P = 0.001], and IC [ P = 0.002, and P = 0.028]) between the two groups during the AP and VP. However, WC ( P = 0.930, and P = 0.823) was not statistically different between the two groups. The ROC curve analysis showed that the AUC in the AP and VP was 90.9% (95% CI, 0.873-0.945) and 83.4% (95% CI, 0.780-0.887), respectively. The highest diagnostic performance (AUC, 97.6%; 95% CI, 0.961-0.991) was achieved when all spectral CT parameters were combined with clinical variables. Conclusion Dual-energy spectral CT has a significant value in distinguishing SP-TB from S-LUAD.