Regularized maximum likelihood algorithm for PET image reconstruction using a detail and edges preserving anisotropic diffusion

The traditional iterative reconstruction algorithms of positron emission tomography cannot effectively suppress the noise in low SNR case. Recently anisotropic diffusion (AD) is introduced into tomography reconstruction, which can improve the reconstructed image. Although AD reconstruction algorithm can suppress noise, it does not perverse the detail edge information accurately, especially the thin edges. In order to solve the problem, we introduce a new anisotropic diffusion term, which can preserve the detail edges effectively, into the maximum likelihood algorithm, and combine with median filter, forming the regularized maximum likelihood algorithm in PET image reconstruction (PML_NewAD). Results of computer simulated demonstrate that compared with the other classical reconstruction algorithms, PML_NewAD not only availably suppress the noise and produce a higher quality image, but also preserve the structure of image's edge excellently.