Patent ID: 9478049
Filing Date: 2016-10-25
CPC Classification: G06T

Claim Text:
1. A CT image processing method, including the following steps of: receiving projection data acquired of a volume along a scan direction, one or more image points of said volume reconstructable, in an iterative reconstruction operation, from at least a part of said projection data; as a function of a position in a volume reconstructed in a previous iteration or otherwise reconstructed, computing a regularization parameter for an image point at said position for a next iteration in said iterative reconstruction operation; as a function of a scan position along the scan direction, normalizing the regularization parameter relative to a region of interest, ROI, of an object in a plane across the volume at said scan position, the ROI defined by a mask m, wherein the normalizing is via a mean or a weighted mean of the regularization parameter; and when iteratively reconstructing, in said next iteration, said image point from the projection data, applying said normalized regularization parameter, wherein the regularization parameter is computed from a parameterized first function of one or more back-projections of a parameterized second function of spatial variance of noise obtained from the projection data, and the parameterized first function comprises an exponential function with a fixed or an adjustable positive exponent parameter, wherein the positive exponent parameter is less than 1.