Enhanced Visualization of Pulmonary Structures with a Novel Dual-Ring Static CT System

Background Conventional helical CT systems are limited by spatial resolution, which can be insufficient to detect subtle pulmonary abnormalities. A novel prototype static CT system with a dual-ring structure and 24 x-ray sources has been developed to enable ultra-high-spatial-resolution lung imaging. Purpose To assess whether static CT improves the visibility of lung structures compared with conventional helical CT and to determine whether enhanced image quality has a diagnostic impact. Materials and Methods In this prospective study approved by the local ethics committee, 30 patients who had undergone chest CT within the prior 12 months were enrolled between April and December 2024. Each patient underwent dose-matched scanning with the prototype system. Images were reconstructed with a 3072 × 3072 matrix and 0.165-mm section thickness. Three thoracic radiologists independently rated the visibility of 11 lung structures on a five-point Likert scale (from -2 to 2). Objective metrics, including modulation transfer function, signal-to-noise ratio, contrast-to-noise ratio, and the number of visible bronchial generations, were assessed. Interobserver agreement was evaluated with Fleiss κ coefficients, and Wilcoxon signed rank tests were used for comparisons (P < .01 was indicative of a statistically significant difference). Results Among the 30 patients who were included (mean age, 55 years ± 9; 18 men), the static CT system demonstrated improved visibility in eight of 11 pulmonary structures (all P < .01). Objective analysis confirmed a higher spatial resolution for the prototype (10% modulation transfer function: 25.5 vs 18 line pairs per centimeter) and visualization of more distal bronchial generations (median, 9 vs 7), albeit with lower signal-to-noise ratio and contrast-to-noise ratio (both P < .001). Although visibility scores were higher than 0, they remained below the "diagnostic impact" threshold of 2 (all P < .01). Interobserver agreement was excellent (Fleiss κ = 0.828). Conclusion The prototype stationary multisource CT improved the visualization of fine pulmonary structures at similar radiation doses. © RSNA, 2026 Supplemental material is available for this article.