Kalpana M. Kanal, PhD, DABR, Past Chair of the American College of Radiology® (ACR®) Dose Index Registry, contributed this post.
In Oct. 2021, the ACR shared the news about the publication in Radiology of diagnostic reference levels (DRLs) and achievable doses (ADs) for the ten most commonly performed pediatric computed tomography (CT) scans. This long-awaited publication on dose benchmarks was generated through an analysis of data from the ACR Dose Index Registry (DIR) to help imaging facilities and providers compare their local doses to national benchmarks and optimize radiation dose used in children’s imaging.
Data from over 1.5 million pediatric CT examinations submitted to the DIR by over 1,600 facilities ranging from academic, community and children’s hospitals acquired from 2016 to 2020 were utilized in our analysis. Of note, this is the first time national pediatric DRLs and ADs have been developed as a function of both patient age and size.
This week, I had the opportunity to present an abstract during RSNA 2021 highlighting the details of this study. Data on the ten most commonly performed pediatric CT examinations acquired were analyzed. For head and neck examinations, doses were analyzed based on patient age; for body examinations, doses were analyzed based on both patient age and effective diameter. Data from over 1.5 million pediatric CT examinations provided medians (AD) as well as 75th percentiles (DRL) for CTDIvol, DLP and SSDE. Of all facilities analyzed, 65.2% of the facilities were community hospitals, 16.8% were freestanding centers, 9.5% were academic facilities and only 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.
The results of this study will enable stateside and international facilities to compare their patient dose indices to these benchmarks. Because smaller and younger patients require less radiation to obtain adequate image quality, the new DRLs and ADs will enable facilities to adjust their CT protocols more effectively for the wide range of patient habitus and age commonly seen in the pediatric population.
Together, radiologists, medical physicists and radiologic technologists can ensure that each patient receives an optimized dose while maintaining image quality.