Iterative image reconstruction with dynamic suppression of formation of noise-induced artifacts

Abstract

Iterative reconstruction () of imaging data is performed to generate a sequence of update images () terminating at a reconstructed image. During the iterative reconstruction, at least one of an update image and a parameter of the iterative reconstruction is adjusted using an adjustment process separate from the iterative reconstruction. In some embodiments using an edge-preserving regularization prior (), the adjustment process () adjusts an edge preservation threshold to reduce gradient steepness above which edge preservation applies for later iterations compared with earlier iterations. In some embodiments, the adjustment process includes determining () for each pixel, voxel, or region of a current update image whether its evolution prior to the current update image) satisfies an artifact feature criterion. A local noise suppression operation () is performed on the pixel, voxel, or region if the evolution satisfies the artifact feature criterion and is not performed otherwise.