Study On The Key Technology Of Teeth Body 3D Reconstruction Based Micro-CT

Three dimensional reconstruction of medical images is an important part in medical images'research. This paper regarded the key problem in the process of teeth virtual surgery as research emphasis. On the premise of the medical CT datas used as experimental data, the problem of CT image pretreatment was studied. It proposed a new image segmentation method on the basis of analyzing the Snake image segmentation, and realized three-dimensional reconstruction using the improved ray casting method; This paper studied the metal and artifacts producted by mechanical vibrations in the medical CT data acquisition, and the method is proposed to eliminate artifacts.At the part of image pretreatment, first, this paper improved the window function on mapping of the DICOM data to make it be more smooth when accommodate. Then it analyzed various types of noise, and utilized mean filter, median filter and wavelet filter to carry on the filter pretreatment. The experimental results show that wavelet filter can protect the edge of teeth and advance the resolution of interlayer.Image segmentation is an important step for visualization of three-dimension data, and put a basis for later three-dimensional reconstruction. In the paper, it proposed the improved Snake image segmentation algorithm in view of medical images with their own ambiguity and uneven nature. According to the corresponding teeth CT medical images, the segmentation experiment is carried out, the experimental results showed that the method could take the edge of the teeth and local outlines out of the background, and retained the image features information better.Furthermore, in view of the obtained CT image data, it proposed a improved ray casting method combining with image interpolation algorithm, which can quicken the reconstruction speed of the ray casting method, then performed the reconstruction using the images treated above, and we got a realistic view of the three-dimensional structure. The experiment shows that the edge characteristics of the reconstructed image are continuous, the regions and parts are also obvious. Doctors can observe the size and shape of each part, as well as the spacial geometric relationship with their surrounding tissues, which has a great theory and application significance for medical diagnosis.Finally, through weakened metal and streak artifacts producted by mechanical vibrations, the problem of artifacts met in CT technology practice are studied, simulation and reconstruction is carried for artifacts producted by CT mechanical vibrations and metal, and the method to eliminate artifact is proposed from angles of artifact production.