Research On Pelvic Medical Image Registration And 3d Visualization Technology

As a typical trauma of orthopedics,pelvic fracture has a high rate of disability and fatality,which is usually accompanied by some complications and increases the difficulty of doctors’ surgery.In routine pelvic surgery,doctors directly look at preoperative CT to determine the damage to the pelvis,and X-rays are used to determine the current position of pelvic reduction.This method relies heavily on the doctor’s surgical experience,with a certain degree of subjectivity,and the accuracy of the reduction is difficult to guarantee.Therefore,a system is needed that can visualize pelvic medical images to help doctors observe pelvic fractures more intuitively,and at the same time simulate pelvic reduction surgery,so that doctors can develop a clearer reduction path and complete reduction surgery.Therefore,in view of the defects and needs of current pelvic surgery,this paper studies the pelvic medical image registration technology and three-dimensional visualization technology,and develops a pelvic surgery navigation system to assist doctors in completing pelvic fracture surgery.The main research content of this paper is as follows:(1)The generation principles and image characteristics of different pelvic medical images,as well as the analysis of their data storage formats,were studied.It enables the reading and display of different medical images.At the same time,the medical image preprocessing technology is studied,including the research of algorithms such as medical image filtering and segmentation,which removes the noise in the image and segments the bone data of the pelvis,which provides a data source for the latter step of threedimensional visualization.(2)Two three-dimensional visualization algorithms,surface drawing and volume drawing,were studied.The three-dimensional visualization of pelvic CT images by traditional MC algorithm and light projection algorithm is realized,and a new improved MC algorithm is implemented to view the ambiguity of voxels in traditional MC algorithm and the shortcomings of excessive data of the reconstruction model.Aiming at the disadvantage of slow reconstruction speed of ray projection algorithm,an improved ray projection algorithm is proposed,which uses inverse distance-weighted interpolation instead of triple linear interpolation,and uses GPU image hardware to accelerate data processing.Finally,the 3D visualization of pelvic CT images is realized in the VTK platform.(3)The medical image registration algorithm was studied.The framework of 2D/3D registration and the key technologies to realize 2D/3D registration algorithm are deeply studied,the pelvic 3D CT image is reconstructed into a two-dimensional DDR image using digital image reconstruction technology,different similarity measures are studied,and a 2D/3D registration algorithm based on normalized mutual information is proposed,and the pyramid algorithm is used to accelerate the registration speed.Finally,an experiment is built on the ITK platform to verify the accuracy and robustness of the algorithm.(4)Based on VTK,ITK and Qt,a set of pelvic surgery navigation system is realized.The image preprocessing algorithm,3D visualization algorithm and 2D/3D registration algorithm are integrated into this system,and interactive operation functions such as coordinate acquisition,angular distance measurement,arbitrary plane cutting,singlemodel moving rotation scaling,multi-model relative movement rotation,and reset path generation are developed.