The cone-beam algorithm of Feldkamp, Davis, and Kress preserves oblique line integrals.
The algorithm of Feldkamp, Davis, and Kress [J. Opt. Soc. Am. A 1, 612-619 (1984)] is a widely used filtered-backprojection algorithm for three-dimensional image reconstruction from cone-beam (CB) projections measured with a circular orbit of the x-ray source. A well-known property of this approximate algorithm is that the integral of the reconstructed image along any axial line orthogonal to the plane of the orbit is exact when the cone-beam projections are not truncated. We generalize this result to oblique line integrals, thus providing an efficient method to compute synthetic radiographs from cone-beam projections. Our generalized result is obtained by showing that the FDK algorithm is invariant under transformations that map oblique lines onto axial lines.
Department of Nuclear Medicine, Vrije Universiteit Brussel, AZ-VUB, B-1090 Brussels, Belgium.
Thomas
T
Rodet
Frédéric
F
Noo
Michel
M
Defrise
D000465:Algorithms; D021621:Imaging, Three-Dimensional / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D036542:Tomography, Spiral Computed / Q000379:methods*