Performance Evaluation of Exact Cone-Beam Algorithms for the Long-Object Problem in Spiral Computed Tomography

INTRODUCTIONSpiral Computed Tomography (CT) with area detectors isof increasing interest for scanning large volumes in a shorttime and achieving isotropic resolution. When the cone-angleis large, exact reconstruction algorithms are needed which gobeyond approximate solutions.A major problem of spiral cone-beam CT is the so-calledlong-object problem, which concerns the exact reconstructionof a region-of-interest (ROI) of a long object using projectiondata of a pure spiral scan...