基于CT值的外轮廓提取方法在精确放疗计划制定中的实现

目的 给精确放疗计划制定中的剂量计算和人体外形三维重建提供准确的外轮廓。方法借助W／L算法，在分析CT值与人体组织关系的基础上，用基于CT值的方法实现人体外轮廓的提取。结果和常用的外轮廓提取方法相比，提取的结果基本一致，但速度提高了2．5倍。结论基于CT值的外轮廓提取方法无需进行二值化，能快速准确地提取人体的外轮廓，在精确放射治疗方面的应用性较强。

Implementation of outside contour extraction based on CT number in making plan of accurate radiotherapy

Objective To supply more precise outside contour for dose calculation and 3D reconstruction in accurate radiotherapy. Methods With the W/L algorithm, the automatic outside contour extraction based on CT number was realized, after the relation between CT number and the tissue of human body had been analyzed. Results The speed in this way was 2.5 times greater than the traditional one with the same results. Conclusions The method of outside contour extraction based on CT number need not to be bivalued, and the precise outside contour of human body can be obtained quickly. This method might have good application in accurate radiotherapy.