Study On Medical Imaging 3D Construction And Visualization Technology

Medical Imaging Visualization is a kind of technology that can process 3D Volume Data which comes from 2D digital tomographic images, and transforms the medical imaging data to 3D graphics and images, which can be displayed on computer screen to show 3D appearance of human people, by means of computer technology and human vision. This technology is one of the most important hotspots in the current medical imaging research, it is not only important to theory research, but also valuable and helpful for clinic diagnosing and so on.In this thesis, based on the need for medical imaging processing and the current condition of medical equipment in our country, the characteristics of the CT or MRI image data and pretreatment methods were introduced and it makes research into the different methods of Medical Imaging Visualization, their advantages and disadvantages and the accelerating algorithms of volume rendering. Putting emphasis on ray casting algorithm, introduced the visualization software VTK, discussed 3 kinds of raycasting algorithms: MIP method, isosurface method, composition method used in VTK, completed 3 experiments and a evaluation of these algorithms was given. Then the isosurface method was optimized getting a good visualization effect.Aim to the problems of powerful computing capacity and slow rendering velocity, this paper synthetically analyzed all speedup technique of volume rendering, then a re-sampled speedup algorithm of ray casting volume rendering is proposed. Firstly, the projection of 3D datasets on image plane is used to reduce the number of rays. Second, utilizing boundary box technique avoids the sampling in empty voxel and greatly improves the efficiency of ray casting. The speedup algorithm overcomes the limitation existing in traditional algorithms that have not a distinct improvement in rendering speed. This algorithm can produce the required quality images and improve the rendering efficiency remarkably. At last to reconstruct 3D medical imaging using the accelerating algorithm of ray casting in the environment of VC++6.0 with OpenGL technology, the correctness and high efficiency of the accelerating algorithms for ray casting are validated .