CT Projection Reconstruction Method Based On OPED And3D Visualization

Computed Tomography technology (CT) is a kind of nondestructive imaging technology, which is used to reconstruct computed tomography images to show clearly the anatomy of human body and reveal the changing process of both physiology and pathology. It is not surprising that CT technology is one of the most important tools in21st in Diagnostic Medical Imaging field, and also a popular topic in academic research. CT reconstruction methods, the most essential part among CT technology, will be discussed in this paper, including CT projection reconstruction method and3D visualization technology. To be more specific:First of all, a reconstruction method OPED (orthogonal polynomials expansion on a unit disk) will be deduced. The properties of local entropy and gradient in the image is introduced to control the diffusion in anisotropic diffusion model so that we can reduce noise when it comes to noise polluted Radon projection data. And we get an improved anti-noise reconstruction method OPED-PMLE. The method is proved to have good noise reduction performance and reconstruction accuracy.Under the inspiration of OPED which is done on a2D unit disk, some promotion work is attempted into3D condition. A new3D projection reconstruction method OPEC is proposed using the expansion of orthogonal polynomials defined in a unit cylinder accompanied with a new scanning strategy of computed tomography images. The method includes the definition of unit cylinder, the construction of orthogonal polynomial sub-space and its base, and the process of orthogonal series expansion. In order to reduce time complexity, FFT is imported to calculate the DST-I in the expression of expansion.In the experiment, OPEC is compared with traditional method which embodies the feasibility of OPEC and its credible result.In addition to CT projection reconstruction technology,3D visualization technology is also in the discussion. The famous Marching Cube algorithm is introduced and with the help of visualization tool, a3D visualization module is designed and developed. Several experiments are processed to realize3D rendering. The results illustrated good effect with string interaction.