Versatility of the CFR algorithm for limited angle reconstruction

The constrained Fourier reconstruction (CFR) and iterative reconstruction-reprojection (IRR) algorithms are evaluated based on their accuracy for three types of limited angle reconstruction problems. The CFR algorithm performs better for problems such as X-ray CT (computer tomography) imaging of a nuclear reactor core with one large data gap due to structural blocking of the source and detector pair. For gated heart imaging by X-ray CT, radioisotope distribution imaging by PET (position emission tomography), or SPECT (single-photon-emission computed tomography) using a polygonal array of gamma cameras with insensitive gaps between camera boundaries, the IRR algorithm has a slight advantage over the CFR algorithm, but the difference is not significant. Overall, the CFR algorithm is versatile and more practical, especially for a large gap angle geometry, with the additional advantages of less computation time and better convergence