Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Radiology, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA.
J Appl Clin Med Phys. 2022 Sep;23(9):e13721. doi: 10.1002/acm2.13721. Epub 2022 Aug 4.
The purpose of this study was to provide an empirical model to develop reference air kerma (RAK) alert levels as a function of patient thickness or age for pediatric fluoroscopy for any institution to use in a Quality Assurance program. RAK and patient thickness were collected for 10&663 general fluoroscopic examinations and 1500 fluoroscopically guided interventions (FGIs). RAK and patient age were collected for 6137 fluoroscopic examinations with mobile-C-arms (MC). Coefficients of linear regression fits of logarithmic RAK as a function of patient thickness or age were generated for each fluoroscopy group. Regression fits of RAK for 50%, 90%, and 98% upper prediction levels were used as inputs to derive an empirical formula to estimate alert levels as a function of patient thickness. A methodology is presented to scale results from this study for any patient thickness or age for any institution, for example, the patient thickness dependent RAK alert level at the top 1% of expected RAK can be set using the 98% upper prediction interval boundary given by: , where x is the institute's average patient thickness or age, and is the intercept based on the average RAK of the patient population calculated as is the institution's average RAK (mGy). m and s are constants presented for each type of fluoroscope and RAK group and represent slope of the fit and scale factor, respectively. An empirical equation, which estimates alert levels expressed as air Kerma without backscatter at the interventional reference point as a function of patient thickness or age is provided for each fluoroscopic examination type. The empirical equations allow any facility with limited data to scale the results of this study's single facility data to model their practice's unique RAK alert levels and patient population demographics to establish pediatric alert levels for fluoroscopic procedures.
本研究的目的是提供一个经验模型，以便为任何机构开发参考空气比释动能 (RAK) 警示水平，作为儿科透视检查中患者厚度或年龄的函数。为 10663 次普通透视检查和 1500 次透视引导介入 (FGI) 收集了 RAK 和患者厚度。为 6137 次带有移动 C 臂 (MC) 的透视检查收集了 RAK 和患者年龄。为每个透视组生成了对数 RAK 作为患者厚度或年龄函数的线性回归拟合系数。将 RAK 的回归拟合用于 50%、90%和 98%上预测水平，作为输入，推导出一个经验公式，以患者厚度为函数估计警示水平。提出了一种方法，可将本研究的结果扩展到任何机构的任何患者厚度或年龄，例如，可以使用给定的 98%上预测间隔边界设置预期 RAK 中前 1%的患者厚度相关 RAK 警示水平，其中 是机构的平均 RAK（mGy）。 和 是基于患者人群计算的平均 RAK 的截距， 是患者的平均厚度或年龄， 是常数，分别代表拟合的斜率和比例因子。为每种类型的透视仪和 RAK 组提供了一个经验方程，该方程估计了作为患者厚度或年龄函数的介入参考点处的无反向散射空气比释动能的警示水平。经验方程允许任何数据有限的设施将本研究的单一设施数据的结果扩展到模型其实践的独特 RAK 警示水平和患者人群特征，以建立儿科透视程序的警示水平。
