Reconstruction System for Real-Time CT

Abstract

Many applications of computed tomography either require or would benefit from "real-time" data acquisition and image reconstruction. Real-time is a rather nebulus concept that is specific to each application. However, for visual inspection of the image data, real-time may be equated with video-rate processing. There are many applications where projection data can be collected at this rate. Boyd1 has recently described an x-ray gantry that can collect all the projection data in a time on the order of a video frame time. Real-time reconstruction, on the other hand, is quite difficult and has not been demonstrated on data of any appreciable size. We describe a system for real-time image reconstruction. The system implements the filtered back-projection algorithm and is based on an electro-optic implementation of the filtering operation, an optical back-projection, and integration on a video detector. This system when coupled to a fast data acquisition system will enable on-line real-time inspection of a dynamic process (i.e., "CT video").