Patent Number: 
Section: abstract

A computed tomography scanner is disclosed for performing a spiral scan. In at least one embodiment, the computed tomography scanner includes a rotatable X-ray emitter for generating a beam fan and an X-ray detector, positioned diametrically opposite to the emitter, and an associated evaluation unit. In at least one embodiment, provision is made for an X-ray filter arranged downstream of the X-ray emitter, the position of the X-ray filter being correlated to that of the X-ray detector. Further, the X-ray filter is partly inserted into the beam fan only during operation for generating an unfiltered and, simultaneously, a filtered radiation component of the beam fan, wherein the radiation components have different X-ray spectra and wherein the evaluation unit is designed for separate evaluation of a measurement signal of the unfiltered radiation component and a measurement signal of the filtered radiation component, to obtain dual-energy images.