Photon-counting CT in pediatric patients: A multi-institutional evaluation of protocols and radiation exposure in 4,772 patients.

PURPOSE: The purpose of this study was to provide protocol guidance and evaluate radiation dose levels in pediatric photon-counting computed tomography (PCCT) applications.

MATERIALS AND

METHODS

This multi-institutional, retrospective study included data from PCCT examinations performed between January 2024 and May 2025 in three medical institutions. Protocols were developed through expert consensus to optimize image quality and minimize motion artifacts and radiation exposure in children. Volume CT dose indexes (CTDIvol, in mGy) and dose-length products (DLP, in mGy·cm) were collected across ten body regions and stratified into five weight groups.

RESULTS

A total of 4772 patients who underwent a total of 6464 pediatric PCCT examinations were included. There were 2719 male (56.97 %) and 2053 female (43.02 %) pediatric patients with a mean age of 7.9 ± 5.5 (standard deviation [SD]) years (range: 4 days-17.9 years), and a mean weight of 29.6 ± 20.3 (SD) kg (range: 2-79 kg). A total of 2110 PCCT examinations (32.64 %) involved children up to preschool age (< 15 kg and < 4 years). The chest (33.54 %; 2168/6464) and head (25.91 %; 1675/6464) were the most frequent regions examined, followed by the ear, nose and throat (11.36 %; 736/6464), the heart (8.65 %; 559/6464) and the abdomen/pelvis (5.09 %; 329/6464). Median CTDIvol for non-contrast head PCCT ranged from 16.1 to 24.0 mGy and DLP from 311 to 608 mGy·cm, while for non-contrast chest PCCT, median CTDIvol ranged from 0.3 to 0.8 mGy and DLP from 7 to 27 mGy·cm. CTDIvol and DLP increased with patient body weight.

CONCLUSION

This multi-institutional study provides practical protocol guidance for PCCT and updated dose benchmarks adapted to pediatric patients. These findings support the safe integration of PCCT into clinical practice and offer a flexible reference framework that centers can adapt to optimize image quality and radiation protection in children.