【作者】 葛中远；

【导师】 周正东； 戴耀东；

【作者基本信息】 南京航空航天大学 ， 核技术及应用， 2009， 硕士

【摘要】 目前,放射治疗已经成为一种非常重要的肿瘤治疗手段,在进行治疗之前,需要制定精确的放射治疗计划,保证最大程度的照射病灶,而周围的重要组织受到的损伤最小,最终实现精确的放射治疗。可视化技术在放射治疗计划的制定过程中发挥着越来越重要的作用,成为了放射治疗领域中的一个研究热点。因此,对可视化技术的研究,不仅具有重要的学术意义,而且对放射治疗技术的发展具有重要的推动作用。本文对放射治疗计划中的可视化技术进行了比较深入的研究,包括医学图像可视化、数字影像重建和虚拟放疗环境,并借助计算机实现了这些可视化技术。首先,本文对医学图像可视化算法做了详细的讨论,主要研究了Marching Cubes(MC)和Ray-casting(RC)这两种方法,给出了针对性的改进办法,并根据这两种方法实现了面绘制和体绘制。由于序列二维轮廓线重建三维形体在放射治疗计划制定过程中有着重要的应用,本文运用交互式的方法进行断层二维轮廓线的提取,并采用Delaunay三角剖分方法进行轮廓线的表面重建。数字影像重建是放射治疗计划采用的一项关键可视化技术,根据X射线成像的物理原理,将光线跟踪技术运用于数字影像重建,并采用图像增强技术改善图像质量,此外对限制数字影像重建速度和质量的瓶颈进行了分析。为了保证放疗计划的可行性,我们利用OpenGL图形库对虚拟放疗环境进行模拟,研究了一种实时的放射治疗设备碰撞检测方法,试验表明该方法可以有效快速地检测放射治疗计划中潜在的碰撞威胁,有利于医生制定合理高效的放射治疗计划。此外,在理论算法研究的基础上,基于VC++6.0,本文设计与开发了一个医学影像处理软件系统,为今后放射治疗计划系统的开发打下了良好的基础。更多还原

【Abstract】 Radiotherapy technology has already been a very important way for tumor treatment. In order to irradiate the tumor to as high a dose as possible, we must make a precise radiotherapy planning and simulate the process of the treatment before the radiation. The visualization technologies have more and more important effect on radiation treatment planning, and become one research hotspot. The study on visualization is not only important in theory, but also helpful for the development of radiation treatment planning.In this thesis, the visualization technologies are studied in depth, including visualization in medical image, digital radiographic reconstruction (DRR), virtual radiotherapy environment, etc. We have implemented these algorithms in personal computer.Some algorithms related to 3D reconstruction are discussed in detail, especially the Marching Cubes (MC) and Ray-casting (RC). The limitations and improvements of the two methods are introduced, and the surface reconstruction and volume visualization based on the algorithms are implemented. In this paper, the contours are outlined interactively, and visualization on the contours is completed based on the Delaunay technology.DRR is one of the key visualization technologies in treatment planning. In this paper, ray tracing is used to generate the DRR, and some methods are well studied to enhance the results of DRR.To guarantee the execution of radiotherapy planning, one method for real-time collision detection between radiotherapy equipments is studied. The virtual radiotherapy environment is simulated based on the OpenGL graphics library. Experiments show that the method can detect the potential collision effectively, and it could be very useful for the design of radiation treatment planning.Finally, by using VC++6.0, we developed a medical image processing software which could be very useful for the development of radiation treatment planning.更多还原