Achievable Doses and Diagnostic Reference Levels In Pediatric Photon Counting Detector CT
Abstract
Purpose
Diagnostic reference levels (DRLs) and achievable doses (ADs) have been established in the United States for pediatric energy-integrating detector CT (EID-CT) based on ACR Dose Index Registry data. However, these benchmarks may not be directly applicable to photon-counting detector CT (PCD-CT), which is increasingly used in pediatric imaging. The purpose of this study is to establish local DRLs and ADs for common pediatric PCD-CT examinations stratified by age and patient diameter. The results are compared with national pediatric EID-CT reference values reported by the ACR in 2022.
Methods
A total of 16,439 acquisitions (10,076 body; 6,363 head) between January 1, 2023 and March 31, 2025 from a single PCD-CT scanner (Siemens Naeotom Alpha Peak) were collected at a tertiary children’s hospital. High-volume neuro (head, maxillofacial, neck) and body protocols (chest, abdomen, pelvis) were analyzed in detail with respect to CTDIvol, SSDE, and DLP for patients ≤18 years old. Direct comparison to the 2022 ACR study was achieved through the use of the same age and diameter categories.
Results
The highest volume exams were head without contrast (2,977, 18%) and abdomen/pelvis with contrast (1,677, 10%). ADs and DRLs for all three dose metrics tracked increased with both age and patient diameter in body and neck protocols, as expected. Much less change was observed for CTDIvol and SSDE across age and size groups for head and maxillofacial protocols. The observed PCD-CT dose metrics were consistently lower than those reported in the 2022 ACR study for pediatric EID-CT. Reductions ranged from 20-80% for body protocols and from 10-70% for neuro protocols. The most substantial decreases were generally observed for the oldest age group (neuro: 6-18 yrs; body: 15-18 yrs).
Conclusion
Pediatric dose benchmarks for PCD-CT were established, providing a reference to support protocol optimization and clinical implementation across institutions.