Filtered-backprojection algorithm for astigmatic SPECT reconstruction
A filtered backprojection algorithm is presented for astigmatic collimation. The reconstruction algorithm is derived based on the image reconstruction algorithm derived by Feldkamp et al for cone beam collimation. The derived algorithm is validated based on Monte Carlo simulated data. Using the astigmatic reconstruction algorithm, we demonstrate the capability of astigmatic collimation to balance the trade-off among axial blurring, field-of-view, and collimator sensitivity for selecting a convergent beam collimation. Reconstructed images also demonstrate that astigmatic collimation can provide improved axial blurring with increased collimator sensitivity compared to cone beam collimation.