Loose S, Leszczynski K W
Department of Medical Physics, Northeastern Ontario Regional Cancer Centre, Sudbury, Canada.
Med Phys. 2001 Aug;28(8):1679-88. doi: 10.1118/1.1387273.
Currently portal imaging devices are used to obtain information on patient localization during radiation therapy treatments. Such obtained information is two dimensional in nature, limited to the plane of the captured image. It has been proposed that megavoltage computed tomography images be reconstructed to overcome this limitation. This study explores the feasibility of reconstructing tomographic images from fan-beam projection data acquired with a commercial portal imaging device on a standard radiotherapy linear accelerator. Several CT reconstruction algorithms are examined as to their performance and suitability for applications in radiation therapy verification. The results show that it is possible, using some of the iterative reconstruction techniques, to obtain an image useful for patient localization from only several (< or =10) projection views.
目前，门静脉成像设备用于在放射治疗期间获取患者定位信息。此类获取的信息本质上是二维的，局限于所捕获图像的平面。有人提出重建兆伏级计算机断层扫描图像以克服这一局限性。本研究探讨了使用商业门静脉成像设备在标准放射治疗直线加速器上采集的扇形束投影数据重建断层图像的可行性。研究了几种CT重建算法在放射治疗验证中的性能和适用性。结果表明，使用一些迭代重建技术，仅从几个（≤10个）投影视图就有可能获得对患者定位有用的图像。
