Abstract

This work relates to the study and characterization of the CTDI (Computed Tomography Dose Index) for the 16 slices CT scanner. The CTDI has been simulated with the Monte Carlo code GATE for PMMA (polymethylmethacrylate) digital phantoms of various diameters (1–50 cm) at various kVp (80, 110, 130) and mAs (100, 200, 300, 400 mAs) levels. After using a High-Performance Computing (HPC) station, a good agreement was observed (less than 1.18% for head phantom and 1.85% for body phantom for all applied voltages) between simulations and experimental measurements with standard PMMA phantoms. Results of simulations demonstrated the following. Firstly, GATE is an adapted tool to estimate CTDI values and can be used to optimize CT parameters in clinical applications. Secondly, Monte Carlo simulation may be able to estimate the absorbed dose when the CTDI method has limitations (use of homogeneous standards cylindrical phantom, the dose measurement in air not in tissue).

中文翻译：

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使用GATE的计算机断层摄影剂量指数（CTDI）的蒙特卡罗模拟

摘要

这项工作与16层CT扫描仪的CTDI（计算机断层摄影剂量指数）的研究和表征有关。CTDI已使用Monte Carlo代码GATE在不同的kVp（80、110、130）和mAs（100、200、300、400 mAs）电平下针对各种直径（1–50 cm）的PMMA（聚甲基丙烯酸甲酯）数字体模进行了仿真。 。在使用高性能计算（HPC）工作站后，在使用标准PMMA体模进行的仿真和实验测量之间，观察到了很好的一致性（对于所有施加电压，头部体模的比例小于1.18％，对于人体体模的比例小于1.85％）。模拟结果表明以下内容。首先，GATE是一种适用于估算CTDI值的工具，可用于在临床应用中优化CT参数。其次，