Incremental Volume Rendering Algorithm for Interactive 3D Ultrasound Imaging

Ryutarou Ohbuchi, Henry Fuchs

Abstract: This paper describes a medical 3D ultrasound imaging system that incrementally acquires and visualizes a 3D volume from a series of 2D images. The system acquires the image from a conventional B-mode 2D echography scanner, whose scanhead is attached to a mechanical tracking arm with three degrees of freedom. It reconstructs a stream of 2D images with their locations and orientations into a 3D array of regularly spaced samples, to be rendered by a modified front-to-back image-order volume rendering algorithm. Visualization is done so that each incoming 2D image slice promptly affects the rendering result. This paper concentrates on the incremental volume rendering algorithm that takes advantage of the incremental scanning to reduce image generation time per each input image slice. We describe a new fast ray-clipping scheme called D-buffer algorithm that is based on the Z-buffer algorithm. It is followed by another speedup scheme called hierarchical ray caching, and a method to efficiently integrate geometric objects with volume data in image space.