Patent Document ID: 8892187
Application ID: 11727751
Patent Status: 1

Claim One:
1. A method for reducing step artifacts in a forward increment direction of a cardio CT representation, the method comprising: recording at least one of (1) volume recordings of first and second sub-volumes of a heart volume and (2) section images of the first and second sub-volumes of the heart volume, which lie adjacent to one another in the forward increment direction and partially overlap in an overlap region, by a computer tomography system, detector data of each sub-volume being used for a reconstruction coming from different heart cycles; determining contrast-to-noise ratios for pixels in the first sub-volume, respectively; selecting first points of the overlap region of the first sub-volume based on the contrast-to-noise ratios associated with the pixels in the first sub-volume, pixels having a contrast-to-noise ratio exceeding a threshold being in the overlap region; selecting second points of the overlap region of the second sub-volume, wherein each second point is selected according to a correspondence between image contents in the vicinity of a corresponding first point and the second point, respectively; determining a field of displacement vectors relative to the second sub-volume based on differences between the first selected points in the overlap region of the first sub-volume and the corresponding second selected points of the overlap region of the second sub-volume, the differences representing displacements between the first selected points and the corresponding second selected points; and subjecting at least a region of the second sub-volume that does not overlap the first sub-volume to a spatial transformation according to the field of displacement vectors, thereby reducing the step artifacts.