Apparatus and method of iterative image reconstruction using regularization-parameter control

摘要

A method and apparatus is provided to predict a regularization parameter for regularized iterative reconstruction of radiation detection data (e.g., computed tomography (CT) data or positron-emission tomography (PET) data) to generate a reconstructed image having specified statistical properties. The predicted regularization parameter is determined using a root-finding method performed on a transcendental objective function. The objective function is calculated using a three-dimensional Fourier transforms of an approximation to a shift invariant Hessian matrix and of matrix products between the forward-projection and back projection matrices of the system model and various (statistical) weight matrices. The specified statistical properties can include the standard deviation within a region of interest, a local spatial resolution, a low-contrast-detectability metric, etc. In addition to the specified statistical properties, the prediction of the regularization parameter accounts for the statistical properties of the radiation detection data, the display field of view, and the system model.