关键词: 正电子发射断层成像（PET）, 各向异性中值扩散, 中值根先验, 图像重建, 抑制噪声

Abstract: For improving the quality of positron emission tomography (PET) images, this paper proposes a new Bayesian image reconstruction algorithm by combining anisotropic median-diffusion filter with median root prior algorithm. Iterations of the proposed method can be divided into two steps: firstly, suppressing noise with the anisotropic median-diffusion filter; secondly, reconstructing image with median root prior algorithm. Simulation experiment  results present that the proposed algorithm can effectively suppress noise and accurately preserve edges information in PET image reconstruction. Furthermore, in comparison to other similar reconstruction algorithms, the proposed method absorbs the advantages of the anisotropic median-diffusion filter and is less sensitive to the selection of the image    gradient threshold and diffusion number, thus making the application of PET image reconstruction feasible.

Key words: positron emission tomography (PET), anisotropic median-diffusion, median root prior, image reconstruction, suppressing noise