Design Of PACS System & Visualization Algorithms In PACS Environment

The goal of PACS (Picture Archiving and Communication System) is to utilize the advanced technology of medical imaging and computer network to solve the problems of acquisition, storage, transmission, viewing, search and coding the huge amount of data of medical image to catch up with the rapid development of networklized information management of modern hospitals. The research and development of PACS has been carried on by many researchers and companies for years, but there are still problems hampering to build a really suitable PACS, which could really benefit the hospitals especially in China.To help hospitals with advanced science and technology related with PACS and to train doctors and technicians to work with and maintain a PACS, the PLA's Key Lab. Of Medical Imaging, supported by PLA's key research project of 10 Five-Year Plan, developed an advanced research system of PACS called IMPAX2.0. I had the honor to become a member of the group and did the research on the development of IMPAX2.0.The research work with this group became the main topics of the thesis. I investigated into the user's requirements coming from different kinds of hospitals for PACS, and paid special attention to them in the designing and developing of IMPAX 2.0. At the same time, I proposed two new algorithms for visualization and display 3D image data in PACS environment. One is to improve the display quality of surface rendering, and the other is to speed the computation for volume rendering based on PC hardware architecture.The main topics discussed in the thesis consist of three parts:(1) The design and implementation of IMPAX2.0 based on accumulated research results of our lab. Recently, research and development of PACS is a hot-point in biomedical engineering and modernization of hospitals. The goal of PACS is to utilize the advanced technology of medical imaging and computer network to solve the problems of acquisition, storage, viewing, search, coding and delivery of medical images which delayed the development of modern hospitals. In this part, how to develop a PACS system that will soon be tested and run in a clinical environment is discussed.(2) A new isosurface smoothing algorithms is proposed. In former studyof 3D isosurface display, surface vector smoothing method is adopted. It can sometimes give good results, but some useful surface features and small feature angles might be lost in some cases. In this paper, the signal processing methods are introduced to improve the effect of display by regarding surface vectors as discrete vector signals and implementing low-pass filtering on them. Not only the number of smoothing iteration is reduced dramatically, but also useful surface features and small angles are better reserved.(3 ) Real-time volume rendering is studied based on modern PC hardware environment. It is a clear trend that PC hardware environment will become the basic platform for many visualization applications including PACS. Volume rendering on PC hardware environment is still in a cradle due to the large amount of trilinear interpolations. With more and more kinds of PC graphics cards supporting the specification of OpenGL1.3, there are many rendering pipeline hardware improvements in those new graphics cards. These hardware structure changes were introduced and then an improved texture mapping volume rendering algorithm based on the new hardware architecture is presented and implemented, which produced better results with less computing time.