A deformable image registration method to handle distended rectums in prostate cancer radiotherapy
A deformable image registration method to handle distended rectums in prostate cancer radiotherapy
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DOI：
10.1118/1.2222077
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发表时间：
2006-09-01
期刊：
影响因子：
3.8
通讯作者：
Dong, Lei
中科院分区：
文献类型：
--
作者：
Gao, Song;Zhang, Lifei;Dong, Lei
在图像引导适应性放疗中，具有自动、准确地描绘直肠壁的能力非常重要，直肠壁是前列腺癌放疗中主要的剂量限制器官。由于图像配准是寻找两个图像之间的空间对应关系的过程，因此基于强度的可变形图像配准的一个主要挑战是处理待配准的两个图像之间的某些对象不存在对应关系的情况。一个例子是直肠内容物由于肠气体的存在和不存在而变化。如果源图像和目标图像之间没有对应关系，则单独基于强度的可变形图像配准方法无法创建正确的空间变换。在这项研究中，我们实施了自动图像强度修改程序，以在规划的计算机断层扫描 (CT) 图像中创建人造气袋。开发了一种基于扩散的变形图像配准算法，以使用自适应平滑算法更好地处理大器官变形。该过程在 15 例前列腺癌病例和 30 张包含最大扩张直肠的每日 CT 图像中进行了测试。当使用图像强度修改程序时，手动描绘的直肠与自动描绘的直肠非常吻合。 (c) 2006 年美国医学物理学家协会。
In image-guided adaptive radiotherapy, it is important to have the capability to automatically and accurately delineate the rectal wall, which is a major dose-limiting organ in prostate cancer radiotherapy. As image registration is a process to find the spatial correspondence between two images, a major challenge in intensity-based deformable image registration is to deal with the situation where no correspondence exists for some objects between the two images to be registered. One example is the variation of rectal contents due to the presence and absence of bowel gas. The intensity-based deformable image registration methods alone cannot create the correct spatial transformation if there is no correspondence between the source and target images. In this study we implemented an automatic image intensity modification procedure to create artificial gas pockets in the planning computed tomography (CT) images. A diffusion-based deformable image registration algorithm was developed to use an adaptive smoothing algorithm to better handle large organ deformations. The process was tested in 15 prostate cancer cases and 30 daily CT images containing the largest distended rectums. The manually delineated rectums agreed well with the autodelineated rectums when using the image-intensity modification procedure. (c) 2006 American Association of Physicists in Medicine.