Image Quality and Radiation Dose Comparison for Abdominopelvic CT Studies Performed Using Photon-counting CT and Dual-energy CT: a Clinical Study

Objectives To compare radiation dose and image quality of abdominopelvic CT studies performed on dual-energy energy-integrating detector CT (EID-CT) and photo-counting CT (PCCT) for the same patient cohort with clinically aligned protocols. Materials and Methods An IRB-approved retrospective cohort study included 49 patients who underwent portal venous phase abdominopelvic CT exams using both dual-energy CT and PCCT scanners within a maximum interval of three months. Images reconstructed included virtual monoenergetic images at 50, 60, and 70 keV and mixed images. CTDIvol values were recorded to assess radiation dose. Regions of interest were drawn in the six anatomical locations for quantitative analysis. The overall image quality, contrast enhancement, image noise, and presence of artifacts were evaluated using a 5-point Likert scale. Results No significant differences were observed in image quality scores between PCCT and EID-CT for most comparisons. Calculated contrast-to-noise ratios (CNR) were significantly higher on PCCT except for 70 keV. PCCT demonstrated a significantly lower radiation dose, with an average reduction of 20 ± 15%, up to 51%. Conclusion For abdominopelvic CT exams with our institutional protocol settings, PCCT has demonstrated a significant reduction in radiation dose while maintaining similar image quality as EID-CT. Advances in knowledge With clinically aligned protocols for the same cohort of patients, the results provided robust evidence for understanding the benefits of PCCT. It also provided a possible pathway to transit from EID-CT to PCCT in the abdominopelvic imaging.