An X-ray imaging method (100) is for generating contrast-enhanced image data (BD) relating to an examination region (FOV) of an object (O) to be examined. Perferably a CT-X ray imaging method is disclosed. In an embodiment of the method, first contrast-agent influenced measured X-ray projection data (PMD1) with a first X-ray energy spectrum (RE1) and at least one set of second contrast-agent influenced measured X-ray projection data (PMD2) with a second X-ray energy spectrum (RE2) are acquired from the examination region. Subsequently, image data assigned to a third X-ray energy spectrum with a third mean energy (E3), based on the first and at least second measured X-ray projection data is reconstructed based on the first and at least second measured X-ray projection data that has been acquired. A mean energy of the first X-ray energy spectrum and a mean energy of the second X-ray energy spectrum are selected as a function of a dimension parameter value of the object that is to be examined. The invention also describes an image data generating device (20) and a computer tomography system (1).
GENERATING CONTRAST-ENHANCED IMAGE DATA BASED ON MULTI-ENERGY X-RAY IMAGING