Research And Application Of Volume Rendering Technology In CT Faulted Image 3-D Reconstruction

3-D CT faulted image reconstruction is to acquire 2-D slices images with medical diagnoses appliance, then to put positions and gray information of these 2-D images into computer, to combine and process them by computer, finally to put out 3-D image of body organ on display. This thesis studies volume rendering algorithm which is the key technology in the 3-D reconstruction. This thesis presents an ameliorated CT faulted image ray casting algorithm, and verify the legitimacy and effectiveness by the application of this algorithm in the reconstruction system.Volume rendering is an essential step in 3-D reconstruction process. In this thesis,it offers a detailed introduction about the relevant content of volume rendering fristly,then discusses the image preprocessing which usually includes filtering and interpolation , in the rendering step, an efficient ray-casting algorithm was presented which improves the traditional ray casting algorithm. The algorithm mainly applies methods of polygon scan conversion and clipping of casting rays, in the re-sampling phase,a quicker tri-linear interpolation algorithm is used, all of these speed up the traditional ray casting algorithm. Based on the step of 3-D CT faulted image reconstruction, the thesis has divided the system into five modules: Image parsing, data pretreatment, image interpolation, rendering and displaying module and realize the performance of modules with relative technology. On the basis of detailed description of the design and implementation of rendering module, the thesis has applied the traditional ray casting algorithm and the new efficient algorithm to the system. The result shows that the new efficient algorithm can speed up the rendering and interaction processes, which providing a good assistant function in the medical teaching and clinic diagnosis.In the end of the thesis, a summary of my work and future imaging of the research are given.