Feasibility of artificial intelligence diagnosis of pulmonary nodules on virtual non-contrast images derived from dual-layer spectral detector CT / 中华放射医学与防护杂志

ABSTRACT

Objective:To evaluate the feasibility of artificial intelligence (AI) diagnosis of pulmonary nodules on virtual non-contrast(VNC) images derived from dual-layer detector spectral CT.Methods:Totally 52 patients who underwent non-contrast and dual-phase enhanced chest CT scan from May 2022 to November 2022 were enrolled in this study. The VNC images of lung were reconstructed based on venous phase data. CT values and image noise of lung parenchyma, signal-to-noise ratio (SNR) were measured. The dose-length product (DLP) of each scan was recorded and the effective dose ( E) was calculated. All of the objective indicators of image quality and radiation dose were compared by Paired t test. Image quality was evaluated subjectively by two radiologists and compared with Wilcoxon non-parametric test. Wilcoxon symbolic rank test was used to compare the sensitivity and false positive detection rate (FPDR) of AI diagnosis between two groups. Results:Compared with TNC, the noise of venous VNC image was decreased by 13.8%, SNR increased by 14.9%, and both of DLP and E decreased by 33.3% ( t=5.82, -5.35, 22.93, 22.92, P <0.05). There were no significant differences in CT values and subjective scores between 2 groups ( P >0.05). For different types of pulmonary nodules, there was no statistical difference in the sensitivity of AI diagnosis between two groups ( P >0.05). For solid nodules with diameter ≤4 mm and all pulmonary nodules in general, FPDR in VNC group was slightly increased with statistical significance ( Z=-2.03, -3.09, P<0.05), while for other types of pulmonary nodules, there was no statistical difference ( P >0.05). Conclusions:The VNC images of thoracic venous phase based on spectral CT can significantly reduce the radiation dose of patients while the image quality and the AI diagnostic sensitivity of pulmonary nodules remain unchanged, and the FPDR without significantly increase. And it could replace TNC for daily routine.