Incremental Volume Rendering Algorithm for Interactive 3D Ultrasound Imaging.

摘要

This paper reported the overview of the incremental, interactive three dimensional ultrasound echography system, where two dimensional image slices are acquired along with their locations and orientations to be reconstructed and volume rendered. The system generates a new image as a new 2D slice is acquired, to maximize interactivity. The visualization algorithm works in incremental manner, limiting the computations to the volume where the new input has arrived. We have established the basics of the efficient incremental volume rendering algorithm, which takes advantage of the incremental nature of the input. We have designed and implemented a faster ray clipping algorithm using polygon scan conversion to clip rays to the slab where the ray should be sampled. The new ray clipping algorithm showed marked improvement over the method we have used before. We have proposed a new ray-caching mechanism called hierarchical ray-cache to speed up the ray-compositing further. We have also proposed an algorithm to render polygonal objects quickly in screen space composited correctly with the volume image. With this proposed algorithm, various operations on the volume image, such as cut-away of a polyhedral volume, insertion of polygons, and highlighting polyhedral volumes will be possible at an interactive rate.