Reconstruction can be made using interpolation. Assume formula_32-projections of formula_16 are generated at equally spaced angles, each sampled at same rate. The Discrete Fourier transform on each projection will yield sampling in the frequency domain. Combining all the frequency-sampled projections would generate a polar raster in the frequency domain. The polar raster will be sparse so interpolation is used to fill the unknown DFT points and reconstruction can be done through inverse Discrete Fourier transform. Reconstruction performance may improve by designing methods to change the sparsity of the polar raster, facilitating the effectiveness of interpolation.