From the Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, MLC 5031, Cincinnati, OH 45229-3026 (K.J.S., E.S., S.L.B.); University of Cincinnati School of Medicine, Cincinnati, Ohio (K.J.S., E.S., S.L.B.); National Radiology Data Registries, American College of Radiology, Reston, Va (D.S.); and Department of Pediatrics and Emergency Medicine, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pa (J.R.M.).
Radiology. 2019 Apr;291(1):158-167. doi: 10.1148/radiol.2019181753. Epub 2019 Feb 5.
Background The American College of Radiology Dose Index Registry for CT enables evaluation of radiation dose as a function of patient characteristics and examination type. The hypothesis of this study was that academic pediatric CT facilities have optimized CT protocols that may result in a lower and less variable radiation dose in children. Materials and Methods A retrospective study of doses (mean patient age, 12 years; age range, 0-21 years) was performed by using data from the National Radiology Data Registry (year range, 2016-2017) (n = 239 622). Three examination types were evaluated: brain without contrast enhancement, chest without contrast enhancement, and abdomen-pelvis with intravenous contrast enhancement. Three dose indexes-volume CT dose index (CTDI), size-specific dose estimate (SSDE), and dose-length product (DLP)-were analyzed by using six different size groups. The unequal variance t test and the F test were used to compare mean dose and variances, respectively, at academic pediatric facilities with those at other facility types for each size category. The Bonferroni-Holm correction factor was applied to account for the multiple comparisons. Results Pediatric radiation dose in academic pediatric facilities was significantly lower, with smaller variance for all brain, 42 of 54 (78%) chest, and 48 of 54 (89%) abdomen-pelvis examinations across all six size groups, three dose descriptors, and when compared with that at the other three facilities. For example, abdomen-pelvis SSDE for the 14.5-18-cm size group was 3.6, 5.4, 5.5, and 8.3 mGy, respectively, for academic pediatric, nonacademic pediatric, academic adult, and nonacademic adult facilities (SSDE mean and variance P < .001). Mean SSDE for the smallest patients in nonacademic adult facilities was 51% (6.1 vs 11.9 mGy) of the facility's adult dose. Conclusion Academic pediatric facilities use lower CT radiation dose with less variation than do nonacademic pediatric or adult facilities for all brain examinations and for the majority of chest and abdomen-pelvis examinations. © RSNA, 2019 See also the editorial by Strouse in this issue.
美国放射学院剂量指数注册中心（American College of Radiology Dose Index Registry for CT）可根据患者特征和检查类型评估辐射剂量。本研究的假设是，学术型儿科 CT 设施已优化 CT 方案，从而使儿童的辐射剂量更低且更稳定。
本回顾性研究使用国家放射学数据注册中心（National Radiology Data Registry）的数据（n = 239 622；年龄范围，0-21 岁），对剂量（患者平均年龄，12 岁）进行了分析（研究年份范围，2016-2017 年）。评估了 3 种检查类型：颅脑平扫、胸部平扫和腹部-盆腔增强静脉造影。使用 6 个不同的体型组分析了 3 种剂量指标：容积 CT 剂量指数（CTDI）、体型特异性剂量估计值（SSDE）和剂量长度乘积（DLP）。使用不等方差 t 检验和 F 检验分别比较了每个体型组的学术型儿科设施与其他设施类型之间的平均剂量和方差。应用 Bonferroni-Holm 校正因子来校正多重比较。
在所有 6 个体型组、3 种剂量指标和 3 种检查类型中，学术型儿科设施的儿科患者辐射剂量均显著更低，且变异更小。在所有颅脑、42 例胸部（78%）和 48 例腹部-盆腔（89%）检查中，均为如此。例如，14.5-18 cm 体型组的腹部-盆腔 SSDE 分别为学术型儿科、非学术型儿科、学术型成人和非学术型成人设施的 3.6、5.4、5.5 和 8.3 mGy（SSDE 均值和方差 P<.001）。非学术型成人设施中体型最小患者的 SSDE 均值为该设施成人剂量的 51%（6.1 比 11.9 mGy）。
与非学术型儿科或成人设施相比，所有颅脑检查以及大多数胸部和腹部-盆腔检查中，学术型儿科设施使用的 CT 辐射剂量更低，且变异更小。
