[当平均CTDIvol值用于计算时,特定位置的器官剂量和尺寸特定剂量估计之间的相对误差]
Yutaka Dendo1, Keisuke Abe1, Shu Onodera1
1Department of Radiology, Division of Medical Technology, Tohoku University Hospital.
Nihon Hoshasen Gijutsu Gakkai zasshi
|October 25, 2023
概括
计算计算机断层扫描 (CT) 扫描的尺寸特定剂量估计 (SSDE) 需要仔细考虑剂量值. 使用调制的CTDIvol进行SSDE计算提供了比使用平均CTDIvol更准确的局部器官剂量评估.
科学领域:
- 医学物理 医学物理
- 辐射科学 辐射科学
- 诊断成像 诊断成像 诊断成像
背景情况:
- 尺寸特定剂量估计 (SSDE) 通过考虑身体习惯,在计算机断层扫描 (CT) 中提供了改善的患者剂量测量.
- 在CT中,自动暴露控制 (AEC) 沿身体轴调节剂量,但显示的剂量指数,如体积CT剂量指数 (CTDIvol),通常是平均值.
研究的目的:
- 调查使用平均CTDIvol与切片特定调制CTDIvol计算SSDE对局部器官剂量准确性的影响.
- 根据AAPM报告第1号,评估开发的计算水等值直径的程序. 220. 这是220.
主要方法:
- 使用人体幻影进行剂量评估.
- 开发并比较了水等值直径计算程序与已建立的程序.
- 使用平均CTDIvol (局部-SSDE平均值) 和调制CTDIvol (局部-SSDE调制) 计算SSDE.
主要成果:
- 与参考系统相比,使用平均CTDIvol计算的SSDE显著高估了肺器官剂量 (18%-56%).
- 使用调制CTDIvol计算的SSDE显示了更高的准确性,相对误差为10% -13%.
- 整个扫描中的平均SSDE在方法之间没有显著差异.
结论:
- 在SSDE计算中使用平均CTDIvol可能会导致局部器官剂量评估中的重大错误.
- 调节的CTDIvol对于使用AEC的CT扫描中精确地估计局部器官剂量至关重要.
- 如果DICOM标题中只有平均CTDIvol可用,则建议使用其他方法,如器官特异性缩放因子,以准确评估剂量.
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