A Two-step Fan-beam Backprojection Slice Theorem

In this work, we propose a theoretical formulation for the tomographic linear fan-beam backprojection having low computational cost. The proposed formula is obtained from a recent backprojection formulation for the parallel case, with low complexity. We provide a Bessel-Neumann series representation for the backprojection without rebinning of measured data onto a parallel geometry. As a consequence of our representation, there is no loss of resolution on the measured data due to interpolation.