抄録
Convolution methods, which are most effective algorithms to the reconstruction of X-ray transaxial tomography, are studied by means of computer simulations. Correction functions which are suggested by Ramachandran, Shepp and Chesler respectively have been compared. The effects, of decreasing number of projections using distributions of a simple disk and a simulated head section have then been considered. Noise propagations have also been considered and we propose “Noise Amplification Figure” as a measure of noise sensitivity, which is a ratio of the standard deviation of reconstructed image to that of projection. This figure is discussed in relation to spatial resolution of reconstruction. The effects of a polichromatic X-ray distortion of the reconstructed images are shown and a correction method of these effects is proposed.
