Area-of-Polygon Based Projection for Simulation and Reconstruction in Fan-Beam X-ray CT

A novel method to simulate a fan-beam X-ray computed tomography (CT) scanner in a digital computer is presented in this paper. The line integral along a ray through the object is computed by splitting the overlap between the ray and the pixellated object into polygons. The line integral is then computed as a weighted sum of areas of these polygons, where the weights convert the areas into line-lengths. To reconstruct the object from the raw data produced by the above simulator, we use a statistical image reconstruction algorithm to produce a noise-free image. The forward projector used in the algorithm is computed using a method similar to that used in the simulator, but approximate areas are used instead to reduce reconstruction time. The main motivation behind the proposed forward projector is to model the scanner as accurately as possible for applications that demand highly accurate reconstructions, e.g. removal of calcium blooming artifacts in cardiac scans.

By: Somesh Srivastava; Vadim Sheinin

Published in: RC24735 in 2009


This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.


Questions about this service can be mailed to .