Registration correction for radiographic scanners with sandwich detectors

This patent describes a radiographic apparatus. It comprises: a source of radiation for projecting a radiation beam through an examination region which receives a subject to be examined radiographically; an array of first radiographic detectors for detecting radiation that has traversed the examination region and generating first signals indicative thereof; an array of second radiographic detectors for detecting radiation that has traversed the examination region and generating second signals indicative thereof; a transform means for deriving an image representation from the first and second signals. The transform means being operatively connected with the first and second detector arrays; a registration correction means for operating on at least one of the first and second signals to correct for spatial misalignment of the first and second detector array. The registration correction means being operatively connected between the transform means and at least one of the first and second arrays