A method for generating an energy-resolved X-ray image is proposed, usable e.g. for mammography or CT applications. First, a preferably low-dose X-ray beam (5) is directed through a region of interest of an object (15) such as a female breast and initial X-ray intensity values are acquired. Based on these initial X-ray intensity values, energy threshold values of for example a photon-counting energy-resolving X-ray detector (9) are specifically adapted to local properties and features of the object (15). With such adapted energy threshold values, energy-resolved main X-ray intensity values are acquired for finally generating the energy-resolved X-ray image. The principle of such specific adapting of energy threshold values in energy-resolved X-ray image acquisition may be advantageously implemented in scanning X-ray systems wherein first detector elements (17) of a scanned X-ray detector (9) are used to acquire the initial X-ray intensity values in order to then set the energy threshold values for subsequent detector elements (17) with which main X-ray intensity values are acquired.
