Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT
Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT
复制标题
对接受心脏 PET/CT 和 SPECT/CT 的不同年龄患者进行具有自动曝光控制的低剂量计算机断层扫描
作者：
Ching;Bang;Chun;Tung;Shu
目的本研究旨在评估自动曝光控制（AEC）的有效性，以优化不同年龄患者接受心脏PET/CT和单光子发射计算机断层扫描/计算机断层扫描（SPECT/CT）的低剂量计算机断层扫描（CT）方案。方法分别使用PET/CT和SPECT/CT对1岁、5岁、10岁儿童和1名成人的4个仿真模型进行CT扫描。对于本研究中研究的混合系统，AEC激活时进行的心脏CT扫描的辐射剂量和图像质量主要取决于预定义图像质量指标的选择。使用多元线性回归方法分析来自拟人体模研究的图像数据，以研究身体尺寸和预定义的图像质量指数对心脏PET/CT和SPECT/CT扫描中的CT辐射剂量的影响。结果回归方程的决定系数大于0.9，拟合效果良好。根据回归模型，针对不同年龄的患者优化了使用AEC技术的低剂量方案。与我们的临床常规实践中使用的成人心脏检查激活AEC的标准方案相比，PET/CT中的优化儿科方案允许模拟10岁、5岁和1岁儿童的拟人幻影分别减少32.2%、63.7%和79.2%的CT剂量。心脏SPECT/CT的相应结果分别为8.4、51.5和72.7%。结论AEC是降低心脏PET/CT和SPECT/CT中CT辐射剂量的一种实用方法，但应适当选择AEC设置，以达到最佳效果。我们的研究结果表明，AEC并没有消除需要儿科协议和CT检查使用AEC技术应优化儿科患者，以减少辐射剂量尽可能低的合理实现。
Purpose This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). Methods One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. Results The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. Conclusion AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.