The application study of dual-energy CT nonlinear blending technique in pulmonary angiography*

Abstract

Abstract Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography (CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB) technique of dual-energy CT. Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energy scanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group, 80 kV group, and 140 kV group) were reconstructed after scanning; 31 patients underwent single-energy scanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and right pulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonary arteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the five groups were calculated. The subjective image quality of the five groups was assessed. The radiation doses of the dual- and single-energy groups were recorded and calculated. Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than those in the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05; SNR of pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR and SNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergy group was lower than that of the single-energy group (t = -4.52, P < 0.05). The subjective scores of images in the NLB group were the highest (4.28 ± 0.74). Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reduce the radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.