title: Artifact analysis of approximate helical cone-beam CT reconstruction algorithms.
abstract: In this paper, four approximate cone-beam CT reconstruction algorithms are compared: Advanced single slice rebinning (ASSR) as a representative of algorithms employing a two dimensional approximation, PI, PI-SLANT, and 3-PI which all use a proper three dimensional back-projection. A detailed analysis of the image artifacts produced by these techniques shows that aliasing in the z-direction is the predominant source of artifacts for a 16-row scanner with 1.25 mm nominal slice thickness. For a detector with isotropic resolution of 0.5 mm, we found that ASSR and PI produce different kinds of artifacts which are almost at the same level, while PI-SLANT produces none of these artifacts. It is shown that the use of redundant data in the 3-PI method suppresses aliasing artifacts efficiently for both scanners.
authors.affiliation: Philips Research Laboratories, Sector Technical Systems, Hamburg, Germany. thomas.koehler@philips.com
authors.forename: Th
authors.initials: T
authors.lastname: Köhler
authors.forename: R
authors.initials: R
authors.lastname: Proksa
authors.forename: C
authors.initials: C
authors.lastname: Bontus
authors.forename: M
authors.initials: M
authors.lastname: Grass
authors.forename: J
authors.initials: J
authors.lastname: Timmer
mesh_terms: D000465:Algorithms; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015233:Models, Statistical; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*; D014965:X-Rays