Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Japan.
Department of Radiology, Kitasato University Hospital, Sagamihara 252-0375, Japan.
Tomography. 2022 Apr 1;8(2):985-998. doi: 10.3390/tomography8020079.
The diagnostic reference levels (DRLs) for pediatric brain computed tomography (CT) are provided for groups divided according to age. We investigated the relationships of radiation dose indices (volume CT dose index and dose length product) with age and weight, as continuous variables, in pediatric brain CT. In a retrospective analysis, 980 pediatric brain CT examinations were analyzed. Curve fitting was performed for plots of the CT dose indices versus age and weight, and equations to estimate age- and weight-dependent standard dose indices were derived. Standard dose indices were estimated using the equations, and the errors were calculated. The results showed a biphasic increase in dose indices with increasing age and weight, characterized by a rapid initial and subsequent slow increase. Logarithmic, power, and bilinear functions were well fitted to the plots, allowing estimation of standard dose indices at an arbitrary age or weight. Error analysis suggested that weight was mildly better than age and that the best results were obtained with the bilinear function. Curve fitting of the relationship between CT dose indices and age or weight facilitates the determination of standard dose indices in pediatric brain CT at each facility and is expected to aid the establishment and application of the DRLs.
儿科脑 CT 的诊断参考水平（DRLs）是按年龄分组提供的。我们研究了辐射剂量指标（容积 CT 剂量指数和剂量长度乘积）与年龄和体重作为连续变量在儿科脑 CT 中的关系。在回顾性分析中，对 980 例儿科脑 CT 检查进行了分析。对 CT 剂量指标与年龄和体重的关系进行了曲线拟合，并推导出了估计年龄和体重相关标准剂量指标的方程。使用这些方程估计了标准剂量指标，并计算了误差。结果表明，剂量指标随年龄和体重的增加呈双相增加，表现为初始快速增加和随后缓慢增加。对数、幂和双线性函数对这些图拟合良好，允许在任意年龄或体重下估计标准剂量指标。误差分析表明，体重比年龄略优，双线性函数效果最好。CT 剂量指标与年龄或体重关系的曲线拟合有助于确定每个机构的儿科脑 CT 的标准剂量指标，有望有助于 DRLs 的建立和应用。
