项目名称： 肝脏介入治疗图像导航系统及其关键技术的研究

项目编号： No.60805047

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 无线电电子学、电信技术

项目作者： 谢小辉

作者单位： 中国科学院深圳先进技术研究院

项目金额： 22万元

中文摘要： 由于软组织容易变形和移动，肝脏介入治疗中需要医学影像引导，为医生提供病灶区域的精确位置信息。本项目通过研究三维重建和分割技术，实现DICOM图像文件的多平面重组、手动和自动协同分割、基于立方体的面绘制、基于体积投射的体绘制等算法，实现了一种能够进行术前治疗规划的三维可视系统，提供与治疗相关医学信息。为实现术前和术中图像的配准，通过建立基于互信息的配准算法研究平台，以模块的形式把四个配准要素：插值算法、配准测度、空间转换函数和优化算法，集成到配准方案中。通过设置不同的图像采样比例、B样条曲面控制点数、搜索步长值和收敛条件，结合LBFG优化算法和常规梯度下降优化算法，提出了新型的分层配准策略，使二维多模态图像配准在速度和精度上都有明显的提高。应用CT体数据转换技术和DRR成像技术，实现了2D-3D图像配准。并对融入分层配准算法的2D-3D配准方案和传统方案进行了比较，证明此方法的应用价值。最后设计了一种五自由度介入治疗辅助机械臂，集成上述技术并引入虚拟现实技术，建立了机器人的虚拟-现实交互环境，借助于光学和机械臂混合定位技术完成了介入治疗辅助机器人的操作实验，结果证明了系统的可行性。

中文关键词： 图像导航; 机械臂; 虚拟现实; 配准; 定位;

英文摘要： The image-guided system is designed to provide the accurate positioning of lesion area to the doctor. By research on three dimensional reconstruction and segmentation technology, this project has finished several main functions, like DICOM data displaying in MPR, manual segmentation cooperative with automatic segmentation, surface rendering using marching cubes algorithm, volume rendering using volume ray casting algorithm. And also a dynamic simulation algorithm has been developed base on the puncture needle. The results are provided three dimensional visualization system and relative information to help doctor in diagnosis before interventional therapy. To realize the registration between the images before therapy and the images after therapy, a research platform based on mutual information is developed with four elements like interpolation algorithm, registration measures, space conversion function and optimization algorithm which is integrated into registration frame in the standard module. By setting different ratio of image sampling, control points of B-spline surface, the search step and convergence conditions, combined with LBFG and gradient descent optimization algorithm, a new hierarchical registration strategy is proposed. The speed and accuracy have shown significant improvement. The 2D-3D image registration is achieved with the CT conversion technology and DRR technology. The hierarchical registration strategy and the traditional program are compared to prove that this registration scheme is feasible and valuable. In the end, researchers have designed an five degree of freedom interventional therapy robot. A virtual reality enviroment is established to realize mutual virtual and reality operation based on three dimensional visualization and image registration techniques. With the help of hybrid location techniques combined with optical positioning and mechanical arm positioning, the close loop control system for assisted interventional therapy robot is established. Experiments proves the system valuble.

英文关键词： image navigation;robot;virtual reality;registration;positioning