At least one embodiment of the invention relates to a dual-source CT device with two focus-detector systems arranged on a gantry offset at an angle n and at least one embodiment relates to a method for spiral scanning and for the reconstruction of tomographic image data of a patient. In at least one embodiment, the detectors have a different z-width in the system axis direction and a computer system with a program memory with at least one computer program, by which during operation the dual-source CT device controls a spiral scanning of a patient and CT-image data is reconstructed from absorption data obtained from both unequally wide detectors, wherein in particular a spiral is controlled with a couch feed rate per rotation, which is greater than the maximum couch feed rate possible with the narrower detector.
