The Research On Pre-Processing And 3D-Reconstruction Of Medical Image

This dissertation, mostly studies the technology of 3D-reconstruction from medical images.3D-reconstruction from medical images is a multi-disciplinary subject. It is an important application of computer graphics and image processing in biomedicine engineering. It relates to the subjects of digital image processing, computer graphics and some related knowledge of medical. 3D-reconstruction and visualization of medical images are widely used in diagnostic, surgery planning and simulating, plastic and artificial limb surgery, radiotherapy planning, and teaching in anatomy. Study on 3D-reconstruction from medical images has important significance on science and worthiness in practical application.Firstly,introduce the main research contents of 3D-surface reconstruction from medical images. It includes image pre-processing, such as interpolating and filtering, segmenting and extracting tissues or organs of body , constructing 3D-surface models, In this dissertation, key techniques for 3D- reconstructing from medical images (such as CT, MRI images) are studied, In this dissertation, an interactive segmentation method of 3D medical images based on gray-level information is presented.The segmentation process consists of following steps: filtering the images, creating the threshold values after analyzing the gray-level histograms of the whole 3D image and some slice images,binarizing the images,processing the images using properly mathematical morphology operation according to the feature of tissues or regions to extract,and filling the regions using seed fill algorithm.Secondly, discusses the Marching Tetrahedra(MT) algorithm principle and the realization method, analyzes the MT algorithm cuts inhalf uniformly. It assigns the iso-surface value, and has the MT algorithm structure its three dimensional surface model for organization region which divides. Proposed in view of the MT algorithm relevant processing,has avoided the massive duplicated interpolation calculation, has accelerated the reconstruction speed, and records the apex and the triangle surface neighboring conveniently.Thirdly, compared with different reconstruct algorithms and taking account of the features of medicine images and actual requirements, a scheme based on the ray-casting technique was proposed to solve the problem of the 3D-reconstruction of medical images. To improve the rendering speed of ray casting and make the technique shown in the scheme a practical routine in medical applications, a synthesized accelerate algorithm based on matrix transform and boundary box was suggested. Finally, a 3D-reconstruction system of medicine image in the proposed scheme was implemented on a PC platform to obtain a nearly real-time interactive speed. It solved the disadvantages of larges of volume data and the lower speed.Finally, the algorithms proposed in the paper are validated through extensive experiments.