Research And Application Of Cone-Beam CT Reconstruction Algorithm Based On Wavelet

Computer tomography (CT) is a pivotal technology in medical diagnosis. With the increasing demands for the accuracy of medical diagnosis, the advantages of cone-beam CT reconstruction algorithms have become more and more obvious. The research on cone-beam CT reconstruction technique can, on the one hand, improve the reconstruction quality, which is the guarantee of diagnostic accuracy, on the other hand, reduce the reconstruction time, and thus heighten the diagnostic efficiency.First, this paper introduces the principle of simulation method for cone-beam CT projection data. After the discussion of the discrete method, a continuous simulation method of projection data for cone-beam CT is proposed. Experiment results show the advantage of continuous simulation method. This method provides reliable projection data for cone-beam CT algorithm, and is a necessary part for the theory research of cone-beam CT. Second, the author introduces the basic theory of wavelet and the principle of local tomography algorithm. On this basis, a new united local tomography algorithm is proposed. Experiment results show that the proposed algorithm greatly reduces the amount of the projection data used for reconstructing region of interest, and obtains the reconstructed images with high quality. At last, the designing and implementing of the CT system are introduced. In order to reconstruct images with high speed and high quality, the CT system design process is divided into two stages. In the first stage, according to the flow of software development, the use cases analysis and the object analysis of the five modules in CT system are respectively made. The six modules include cone-beam CT image reconstruction module, artifact reduction module, pictures search module, general image processing module and advanced image processing module. In the second stage, the design of FDK reconstruction algorithms, CT system frame and the class of standard for medical imaging are accomplished by using relative cone-beam CT theory.This paper discusses cone-beam CT theory from projection data and local tomography reconstruction algorithm, and puts CT theory into practice through CT system.