Samei Ehsan, Li Xiang, Frush Donald P
Duke University Medical Center, Departments of Radiology, Physics, Biomedical Engineering, and Electrical and Computer Engineering, Carl E. Ravin Advanced Imaging Laboratories, Medical Physics Graduate Program, Durham, North Carolina, United States.
Cleveland Clinic, Imaging Institute, Section of Medical Physics, Cleveland, Ohio, United States.
J Med Imaging (Bellingham). 2017 Jul;4(3):031209. doi: 10.1117/1.JMI.4.3.031209. Epub 2017 Aug 21.
The purpose of this study was to formulate a systematic, evidence-based method to relate quantitative diagnostic performance to radiation dose, enabling a multidimensional system to optimize computed tomography imaging across pediatric populations. Based on two prior foundational studies, radiation dose was assessed in terms of organ doses, effective dose ([Formula: see text]), and risk index for 30 patients within nine color-coded pediatric age-size groups as a function of imaging parameters. The cases, supplemented with added noise and simulated lesions, were assessed in terms of nodule detection accuracy in an observer receiving operating characteristic study. The resulting continuous accuracy-dose relationships were used to optimize individual scan parameters. Before optimization, the nine protocols had a similar [Formula: see text] of [Formula: see text] with accuracy decreasing from 0.89 for the youngest patients to 0.67 for the oldest. After optimization, a consistent target accuracy of 0.83 was established for all patient categories with [Formula: see text] ranging from 1 to 10 mSv. Alternatively, isogradient operating points targeted a consistent ratio of accuracy-per-unit-dose across the patient categories. The developed model can be used to optimize individual scan parameters and provide for consistent diagnostic performance across the broad range of body sizes in children.
本研究的目的是制定一种系统的、基于证据的方法,将定量诊断性能与辐射剂量相关联,从而形成一个多维系统,以优化针对儿科人群的计算机断层扫描成像。基于两项先前的基础研究,根据九个颜色编码的儿科年龄 - 体型组中30名患者的器官剂量、有效剂量([公式:见正文])和风险指数,对辐射剂量进行了评估,作为成像参数的函数。在一项观察者操作特征研究中,对添加了噪声和模拟病变的病例进行了结节检测准确性评估。由此产生的连续准确性 - 剂量关系被用于优化个体扫描参数。在优化之前,这九个方案的[公式:见正文]相似,为[公式:见正文],准确性从最年幼患者的0.89降至最年长患者的0.67。优化后,为所有患者类别建立了一致的目标准确性0.83,有效剂量范围为1至10毫希沃特。或者,等梯度操作点针对各患者类别实现了一致的单位剂量准确性比率。所开发的模型可用于优化个体扫描参数,并在儿童广泛的体型范围内提供一致的诊断性能。