Hyperparameter estimation for emission computed tomography data

Although many statistical methods have been proposed for the restoration of tomographic images, their use in medical environments has been limited due to two important factors. These factors are the need for greater computational time than deterministic methods and the selection of the hyperparameters in the image models. Consequently, deterministic methods, like the classical filtered back-projection (FBP) and algebraic reconstruction (AR), are commonly used. In this work, we propose a method to estimate, from observed image data in emission tomography, the hyperparameters in a Generalized Gaussian Markov Random Field (GGMRF). We use the hierarchical Bayesian approach and evidence analysis to reconstruct the image and estimate the unknown hyperparameters. The method is tested on synthetic images.