Abstract: 3D reconstruction of the intestine is a cryingneed to improve the accuracy of disease detection and treatment.This paper adopts the Visualization Toolkit（VTK） combined with VC++ IDE to reconstruct 3D intestine CT images.The Marching Cubes（MC） is a traditional algorithm for 3D reconstruction of medical images，but it results in ambiguity.To overcome the drawback of large quantity of computation of asymptote method that is commonly used to eliminate ambiguity，this paper proposes an improved MC algorithm：finding the intersections of the ambiguity surface and the iso-surface by linear interpolation，connecting the equivalent points on the faced edge of ambiguity surface，and will get two intersecting lines，then uniquely determine the connection contours through the state value of joint point for the two lines，and finally quickly rebuilding the 3D intestine.Compared with the traditional algorithm，this new algorithm shows that the improved MC algorithm achieves great enhancement in quality and efficiency.

Key words: intestine, 3D reconstruction, Visualization Toolkit（VTK）, Marching Cubes（MC）, ambiguity

摘要： 肠道CT的三维重建是提高肠道疾病诊疗准确性的迫切需要。利用可视化工具包VTK并结合VC++，实现了肠道三维重建。经典三维重建Marching Cubes（简称MC）算法会产生二义性，针对常用的渐近线法消除二义性计算量大的问题，提出了一种改进的MC算法：采用线性插值法求出二义性面与等值面的交点，然后分别连接二义性面对边上的交点形成两条相交直线，最后通过判断直线交点的状态值，来唯一地确定等值线的连接方式，从而快速重建出三维肠道。实验结果表明，利用改进的MC算法比起传统MC算法，在三维重建的质量和效率上都得到了很大的提高。

关键词: 肠道, 三维重建, VTK软件, 移动立方体, 二义性