【作者】 池峰；

【导师】 高新波； 梁继民；

【作者基本信息】 西安电子科技大学 ， 电路与系统， 2004， 硕士

【摘要】 医学影像容积重建是目前医学图像处理领域的研究热点，是计算机图形学和图像处理技术在生物医学工程中的重要应用。它涉及到计算机图形学、数字图像处理、生物医学工程等多种技术，是一项多学科交叉的研究课题。近年来，医学影像容积重建技术在诊断医学、手术规划及模拟仿真、整形及假肢外科、放射治疗规划、解剖教学等方面起着越来越重要的作用。 本文主要针对医学影像容积重建中的若干关键技术进行了系统深入的研究。首先，研究了医学断层图像数据的滤波及层间插值技术，提出了一种基于轮廓形变和对应点匹配相结合的混合插值算法，在实现图像层间插值的同时保持了目标的轮廓形状与灰度信息；其次，对医学影像容积重建效果的逼真度进行了研究，提出了一种基于连续梯度转换函数的交互式透明体绘制方法，使重建效果更加生动、真实。在进行直接体绘制方法的研究中，提出了基于三维空间相关性的快速光线投射体绘制算法和基于分类的快速三线性插值算法，两者的结合保证了体绘制交互显示的实时性；然后，综合分析了基于纹理映射的硬件加速体绘制算法；最后，把所提出的容积重建技术应用于虚拟手术刀的研究与实现中，提出了一种基于组织的容积剖切技术，该方法在原有各种容积剖切技术的基础上增加了组织特性，实现了面向感兴趣目标组织的自由剖切。此外，还实现了一种虚拟手术刀剖切面的平面重建和曲面重建技术。用临床实际数据所做的测试实验表明了本文所提出的医学影像容积重建算法及其应用的有效性。更多还原

【Abstract】 Volume rendering (VR) is a hot subject of medical images processing. It is an important application of computer graphics and image processing in biomedical engineering. Since the VR technique is involved the subjects of computer graphics, digital image processing and some related medical knowledge, it is a multi-disciplinary topic. In recent years, the VR technique for medical images is widely used in diagnosis, surgery planning and simulating, plastic and artificial limb surgery, radiotherapy planning, and teaching in anatomy.In this thesis, some key issues of the VR technique are systematically investigated. Firstly, for the image filters and image interpolation between slices, a integrated interpolation algorithm is presented based on the contour shape and correspondence matching, which keeps the shapes and grays information the objects of interest. Secondly, the fidelity of effect of the VR for medical images is studied, and a continuous-gradient-based method for transparent volume rendering is proposed, which vivifies the results of volume rendering. For the direct volume rendering, this thesis presents an accelerated ray-casting volume rendering algorithm based on three-dimensional space coherence and an accelerated tri-linear interpolation algorithm based on classification, both of which ensure the real-time volume rendering. Thirdly, a new volume rendering method based on the 3D texture mapping hardware assisted accelerating is synthetically analyzed. Finally, all the algorithms and techniques are applied in the research and development of virtual scalpel. A tissue-based volume cutting technique is presented, which adds the characteristic of tissue on the basis of the traditional volume cutting technique and achieves free cutting oriented the object-tissue of interest. In addition, a reconstruction technique of the planar and curved section cut by virtual scalpel is also implemented. The experimental results with the real clinic image data demonstrate the effectiveness of the proposed algorithms and their applications.更多还原