摘要:数字重建放射影像是放射治疗计划和2D-3D医学图像配准中的关键技术。本课题的目的是数字重建放射影像(Digitally Reconstructed Radiograph,DRR)算法的研究与实现。要求在数字图像处理的基础上,综合应用数学、医学、物理等知识,用C++实现DRR生成算法。DRR是通过模拟X射线的衰减和曝光过程,从CT数据中获得类似X射线的成像效果的一种技术。本文在调研了光线跟踪法,splatting算法,shear-wrap算法等DRR的生成算法的基础上,选择采用光线跟踪法进行数字重建放射影像。数字重建放射影像的耗时很长,而图像的生成时间主要取决于光线跟踪算法的计算复杂度,所以如何降低计算复杂度就成为了关键。本文实现了基于光线跟踪算法的数字重建放射影像方法,成像效果良好,发现光线跟踪算法的计算部分对内存的开销较大,当断层图像的数据较多时,为了产生符合要求的图像,需要较多的内存。42339
毕业论文关键词: 医学图像;数字重建放射影像;光线跟踪;
Research and implementation of Digitally Reconstructed Radiograph
Abstract: Digital reconstruction of radiological imaging is the key technology of radiation treatment planning and 2D/3D medical image registration. The purpose of this subject is to research the algorithm of digital radiological image reconstruction and implement it with C++, based on the knowledge of image processing, mathematics, medicine, physics and so on. DRR simulates the imaging of the X-ray attenuation and exposure in body, which gets X-ray image from CT data. Ray tracing method, splatting algorithm, the algorithm of shear – wrap are surveyed and the ray tracing method is applied to get DRR image. It is time-consuming of DRR, which is decided by the complexity of ray tracing method, therefor, how to reduce the computational complexity is the key to DRR. Finally, the Digitally Reconstructed Radiograph based on ray tracing algorithm is implemented, and the imaging result is good. It needs more memory when the CT image data is large.
Keywords: Medical image; Digitally Reconstructed Radiograph (DRR); Ray tracing;
目录
摘要 i
Abstract i
目录 ii
1 绪论 1
1.1 研究背景 1
1.1.1研究目的与意义 2
1.2 本章小结及论文结构 3
2 数字重建放射影像 4
2.1 核心技术 4
2.1.1 交集选择策略 5
2.1.2 灰度插值 5
2.2 数字重建放射图像原理 7
2.3 数字重建放射图像生成 7
2.3.1 CT值及窗宽窗位 8
2.3.2 遍历算法 10
2.3.3 像素平面和步长 12
2.4 本章小结 12
3 实现 13
3.1 设计 13
3.1.1 设计思路 13
3.1.2 DICOM格式 13
3.1.3 BMP格式 15
3.2 开发工具 18
3.2.1 VC++