System and method for iterative image reconstruction

摘要

Methods are provided for iteratively reconstructing an image signal to generate a reconstructed image signal. In one embodiment, sub-iterations of each iteration are performed on pixel or voxel subsets. The subsets may be composed of neighboring or spatially separated pixel or voxels and may extend in the z-direction. In one embodiment, an update step of the iterative reconstruction involves the direct inversion of an approximation of a Hessian matrix associated with the respective subsets. In further embodiments, non-negativity or other limitations or constraints on update values may be enforced.

主权项

1. A method for iteratively reconstructing image data, comprising the steps of:
accessing an initial image; defining a plurality of image element subsets of the initial image, wherein some or all of the plurality of image element subsets correspond to voxels aligned in z such that they share the same (x,y) location; iteratively generating updates to the initial image or a subsequent updated image based on the respective image element subsets, wherein at least one of the updates is generated by directly inverting a respective Hessian matrix or an approximation of a respective Hessian matrix associated with a corresponding image element subset; and terminating the iterative generation of updates upon satisfaction of a completion criterion.