van der Heyden Brent, Schyns Lotte E J R, Podesta Mark, Vaniqui Ana, Almeida Isabel P, Landry Guillaume, Verhaegen Frank
Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, Netherlands.
Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität, München, Am Coulombwall 1, 85748 Garching b. München, Germany.
Phys Imaging Radiat Oncol. 2018 May 25;6:47-52. doi: 10.1016/j.phro.2018.05.004. eCollection 2018 Apr.
Dedicated CT simulation models have the potential to investigate several acquisition, reconstruction, or post-processing parameters without giving any radiation dose to patients. A software program was developed for the simulation and the analysis of single-energy and dual-energy CT images. Simulation and analysis functionalities of the software are described.
In the software, named (VOXelized CT SImulator), the X-ray source, user specified simulation geometry, CT setup and the detector energy response can be varied. CT image reconstructions can be performed with an implementation of the ASTRA toolbox. In the DECT post processing toolkit, GUI tools are provided to calculate effective atomic number, relative electron density, pseudo-monoenergetic images, and material map images. Quantitative CT number validation, based on a RMI 467 tissue characterization phantom model, was performed between experimental and simulated CT scans at three different X-ray tube potentials (80, 120, and 140 kVp) with a third generation CT scanner.
Overall, a good agreement was found for the mean CT numbers of the RMI 467 inserts. For all energies, the maximum difference in CT numbers between experimental and simulated data was below 17 HU for the soft tissues and below 48 HU for the osseous tissues.
The software's simulation algorithm showed a good agreement between the CT measurements and CT simulations of the RMI 467 phantom at different energies. The capabilities of the software are demonstrated by an elaborated dual-energy CT research example.
专用CT模拟模型有潜力在不给患者任何辐射剂量的情况下研究多种采集、重建或后处理参数。开发了一个用于单能和双能CT图像模拟与分析的软件程序。描述了该软件的模拟和分析功能。
在名为（体素化CT模拟器）的软件中，可以改变X射线源、用户指定的模拟几何结构、CT设置和探测器能量响应。可使用ASTRA工具箱的实现进行CT图像重建。在双能CT后处理工具包中，提供了图形用户界面工具来计算有效原子序数、相对电子密度、伪单能图像和物质映射图像。基于RMI 467组织表征体模模型，在使用第三代CT扫描仪的三种不同X射线管电压（80、120和140 kVp）下，对实验CT扫描和模拟CT扫描之间进行了定量CT值验证。
总体而言，RMI 467插入物的平均CT值有良好的一致性。对于所有能量，软组织的实验数据和模拟数据之间CT值的最大差异低于17 HU，骨组织低于48 HU。
该软件的模拟算法在不同能量下RMI 467体模的CT测量和CT模拟之间显示出良好的一致性。通过一个详细的双能CT研究示例展示了该软件的功能。
