Research And Implementation Of Medical Image Three-Dimensional Reconstruction

Three-dimensional reconstruction of medical image is one of the key technologies in field of medical visualization, it could provide information about the shape and the position of patient's focus, and it also could help doctors to make a more accurate diagnosis.In this thesis, the Marching Cubes algorithm of surface rendering and the Ray-Casting algorithm of volume rendering are studied in detail. In order to get a faster rendering and a better rendering result, both of them are improved and used in the radiotherapy planning system.Firstly, in this thesis, the three-dimensional reconstruction algorithm based on medical image is analysed, and their principles and characteristics are studied.Furthermore, research on the principle and rendering pipeline of Marching Cubes algorithm, aim at the huge amounts of triangle patchs after surface rendering, we have made the improvement to original algorithm by using patch diminution and smoothing surface technology. And the reconstructed results and the rendering speed are greatly improved.In addition, study the principle of Ray-Casting algorithm and its relevant technologies, such as image data classification, color and opacity settings, space projection transform, resampling and interpolation, image synthesis, etc. A fast volume rendering algorithm based on Ray-Casting algorithm is given, by using image clipping, adjusting resampling technology and using visibility tests, in order to improve the rendering speed.Finally, a medical three-dimensional reconstruction system for medical image is developed by using Visual C++ 6.0 and visualization toolkit, and used in radiation treatment planning system. The system employs the improved Marching Cubes algorithm, Ray-Casting algorithm and extraction of arbitrary slices based on visualization toolkit, and implements the functions such as surface rendering, volume rendering, three-dimensional clipping, extraction of arbitrary slices, multi-leaf collimator's resetting and so on, which are used in the clinical radiation.