Advanced convergence of iterative reconstruction of circular cone-beam short-scans

The iterative reconstruction of a circular cone-beam short-scan (180° plus fan angle) measurement with algebraic reconstruction technique (ART) is investigated. Simulated projections of a transmission tomography scan of the Forbild head phantom are reconstructed. The reconstruction of the short-scan sinogram with ART is compared with the reconstruction of a Parker weighted iterative update, which compensates for the redundancy of the measured rays. The results show that a Parker weighting improves the image quality of the reconstruction with ART during the first few iterations compared with the standard ART, but that this difference vanishes with increasing number of iterations.