Research And Application Of Medical Imaging Oriented Volume Data Analysis And Measurement Method

With the development of informatization,more and more the hospitals are taking use of PACS(Picture Archiving and Communication Systems)to manage medical images.Most traditional PACS systems display and analyze medical images in two dimensions ways,but 3D technology is getting more and more attention because of its intuition,which is very useful to improve users' efficient.The dissertation researches on 3D display technology and 3D measurement technology in PACS systems and these methods have been incorporated into PACS business software for application.The dissertation's main content is as the following:1)Feature analysis based adaptive ray casting algorithm:Traditional ray casting algorithm's result depends on complex transfer functions,which is difficult to design.This dissertation presents a feature-based adaptive ray casting algorithm that can show inner structural features with simple transfer functions.We analyze scalar value along a ray to extract feature segments,then use several heuristic rules to determine the visibility of the feature segments.Furthermore,the opacity of sample points is calculated.Finally,we can perform volume rendering.For the presented algorithm can adaptively adjust opacity,it can produce perfect result image with simple transfer function and its time performance also meets the basic interaction needs.2)3D widget based measurement method:3D measurement aims to measure and analysis target object by simulating common measurement tools in the real world.3D measurement is conducted in 3D virtual environment.2D interactive devices,such as mouse and keyboard,are difficult to interact with the 3D virtual space directly.Hence,this dissertation is devoted to designing 3D measurements tool based on 3D widget.The measurement tool based on 3D widget contains multiple control points.Under a certain constraint,the user can adjust each control point to change shape and location of the measurement tool accordingly.In this way,the purpose of measurement will be realized.Because the user can adjust each control point under a certain constraint,the simple interactive behavior can be realized through the devices such as mouse.In order to help those users select a certain control point from numerous control points rapidly,this dissertation has proposed a selection method based on color code.By taking use of OpenGL's rendering-to-texture,the rapid selection of control point will be realized rapidly.Some real cases have been used to demonstrate the effectiveness of the method.3)Completing the function-friendly 3D system:The dissertation conveys the text that PACS 3D workstation has been developed and is integrated into the commercial software of project partners because of the above key technologies and a reference of 2D workstation.