Fourier-Based Forward and Back-Projectors in Iterative Fan-Beam Tomographic Image Reconstruction

Abstract—Fourier-based forward and back-projection methods can reduce computation in iterative tomographic image re-construction. Recently, an optimized nonuniform fast Fourier transform (NUFFT) approach was shown to yield accurate parallel-beam projections. In this paper, we extend the NUFFT approach to describe an ( 2 log) projector/backprojector pair for fan-beam transmission tomography. Simulations and experiments with real CT data show that fan-beam Fourier-based forward and back-projection methods can reduce computation for iterative reconstruction while still providing accuracy comparable to their ( 3) space-based counterparts. Index Terms—Fan-beam tomography, iterative tomographic image reconstruction, min-max interpolation, nonuniform FFT. I