A high-speed reconstruction from projections using direct Fourier method with optimized parameters-an experimental analysis

Some issues of the direct Fourier method (DFM) implementation are discussed. A hybrid spline-linear interpolation for the DFM is proposed. The results of comprehensive simulation research are presented. The following reconstruction problems and parameters are emphasized: interpolation, increasing the radial density of the polar raster, filtering, the 2-D inverse Fourier transformation dimension, and considering the cases of noiseless and noisy input data. For the a priori prescribed resolution of the reconstructed image, values of reconstruction parameters have been determined which are optimal with regard to reconstruction quality and computation cost. The computational requirements of the DFM algorithm which correspond to distinct interpolation schemes are compared to one another for CT and MR tomography, respectively. The estimations obtained are compared to computational characteristics of the convolution backprojection method