Purpose: To develop diagnostic reference levels (DRLs) and achievable doses (ADs) for the 11 most commonly performed pediatric CT examinations in the United States (USA) as a function of patient age and size using the American College of Radiology (ACR) CT Dose Index Registry.
Methods: Data on the 11 most commonly performed pediatric CT examinations acquired between 2016 – 2020 from 1637 facilities were analyzed. For head, neck and extremity examinations, doses were analyzed based on patient age; for body examinations, doses were analyzed based on both patient age and effective diameter. Data from 1,562,016 examinations provided medians (AD) as well as 75th percentiles (DRL) for CTDIvol, DLP and SSDE. Results were compared with DRLs from other countries.
Results: Of all facilities analyzed, 65.2% of the facilities were community hospitals, 16.8% were freestanding centers, 9.5% were academic facilities and 3.5% were dedicated children’s hospitals. Head CT was the most frequently performed examination in the study (56.1%) followed by the abdomen/pelvis CT (28.1%). ADs and DRLs (for both CTDIvol and DLP) for all examinations generally increased as a function of age and patient effective diameter. For head without contrast examinations, the CTDIvol AD and DRL ranged from 19-46 mGy and 23-55 mGy, respectively increasing with age. For abdomen/pelvis without contrast examinations, the CTDIvol ADs and DRLs ranged from 2.1-24 mGy and 2.6-28 mGy, respectively with increasing effective diameter. Although international pediatric DRL methodology and results vary, our results fall within the ranges reported across other countries.
Conclusion: DRLs and ADs as a function of patient age and effective diameter were developed from a wide range of USA practice environments for the 11 most common CT pediatric examinations using data from over 1.5 million pediatric examinations. These determinations can serve as practical benchmarks for accountability and for improvement in pediatric CT practice.