1. A CT system for phase-contrast and absorption imaging, comprising: a gantry, rotatable about a system axis; and at least two emitter-detector systems, attached to the gantry with an angular offset to scan a measurement field, a specified distance existing between a radiation focus in a respective emitter and a respective detector with its detector elements in each of the at least two emitter-detector systems, measurement beams being defined by a geometric connection between respective a radiation focus and detector element, and at least two of the at least two emitter-detector systems including different distances between respective radiation focus and detectors.