A Comparative Study of Photon-counting CT and Conventional Energy-integrating Detector CT for Low-dose Chest Scanning in Children

Objective: To evaluate the differences in radiation dose, objective image quality, and subjective image quality between photon counting CT (PCD-CT) and energy integration detector CT (SOMATOM Force) in pediatric patients undergoing chest non enhanced CT examination. Method: A retrospective collection was conducted on 52 pediatric patients who underwent photon counting detector CT (PCD-CT) chest plain scan at the First Affiliated Hospital of Zhengzhou University from April 2024 to May 2025, and on 52 children who underwent energy integration detector CT (SOMATOM Force) chest plain scan at the same hospital from October 2023 to May 2025. In objective image evaluation, calculate the signal-to-noise ratio (SNR), contrast to noise ratio (CNR), and back muscle noise (SD) of the upper and lower lobes of the lungs; In the subjective evaluation of images, the 5-point method scores the overall image quality, lung structure and soft tissue display ability, and motion artifacts of each group of images. The comparison of SNR and CNR between two groups was conducted using independent sample t-test or non parametric test, while the subjective score comparison was conducted using Mann Whitney U test. In objective evaluation, the EID-CT images of SNR lung tissue, CNR lung tissue, and SNR muscle were all lower than those of PCD-CT images, and the differences were statistically significant (P<0.001). In subjective evaluation, the subjective scores of image quality in PCD-CT were higher than those in EID-CT, and the difference was statistically significant (P<0.001). Conclusion: Photon counting CT is superior to EID-CT in terms of objective and subjective image quality, noise reduction, spatial resolution, and tissue contrast.