Infant and toddler’s preoperative chest imaging on photon-counting detector CT: a paired-sample comparison with energy-integrating detector CT on image quality and radiation dose

Photon-counting CT (PCCT) may improve dose efficiency compared with energy-integrating detector CT (EID-CT), but evidence remains limited in very young children undergoing non-contrast preoperative chest CT under real-world clinical protocols. To provide a size-aware matched comparison of radiation dose and image quality between PCCT and EID-CT in infants and toddlers (≤ 36 months) undergoing non-contrast preoperative chest CT, and to examine whether the main findings remained directionally consistent across prespecified strata of age, BMI, and water-equivalent diameter (DW). In this single-center matched cohort study, a prospective PCCT cohort and a retrospective EID-CT cohort were propensity score–matched 1:1 (49 pairs). Dose metrics (CTDIvol, DLP, SSDE) and objective and subjective image quality were evaluated, with subgroup analyses stratified by age (< 12 vs. ≥ 12 months), BMI tertiles, and DW tertiles. The PCCT group showed significantly lower radiation dose metrics (CTDIvol, DLP, and SSDE) compared to the EID-CT group (P < 0.001). In terms of objective image quality, PCCT significantly reduced image noise in all lung lobes and consistently demonstrated higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) (all P < 0.001). Subjective image quality assessments showed no significant difference between PCCT and EID-CT (P > 0.05). Across prespecified age, BMI, and DW strata, PCCT remained associated with lower dose metrics and favorable objective image-quality trends, although these subgroup findings should be interpreted as exploratory. In this matched cohort of infants and toddlers undergoing non-contrast preoperative chest CT, PCCT was associated with substantially lower radiation dose and improved objective image quality compared with EID-CT, and no statistically significant difference was detected in subjective image quality scores between PCCT and EID-CT.