Frequency characteristic study of filtered-backprojection reconstruction and maximum likelihood reconstruction for PET images

The filtered-backprojection algorithm and statistical model based iterative algorithms such as maximum likelihood reconstruction are the two major classes of tomographic reconstruction methods. Here, the authors studied the frequency characteristics of the filtered-backprojection method and the maximum likelihood method under noise free and noisy conditions. The experiment showed that the maximum likelihood algorithm may not generate superior image quality in terms of frequency characteristics