Method for determining geometric imaging properties of a flat panel detector, correspondingly adapted x-ray inspection system and calibration phantom

An X-ray inspection system comprising an x-ray source, a flat panel detector, a calibration phantom comprising at least one discrete geometric object, and an electronic data processing device, wherein

• the x-ray inspection system is adapted to record at least one x-ray image of the calibration phantom placed between the x-ray source and the flat panel detector,
• at least one discrete geometric shape is generated in the x-ray image by imaging the at least one discrete geometric object of the calibration phantom,
• the data processing device is adapted to determine a location-dependent distortion error of the flat panel detector from the at least one x-ray image on the basis of at least one characteristic of the discrete geometric shape,
• all of the at least one characteristics of the at least one discrete geometric shape used for determining the location-dependent distortion error are independent of the dimensions of the calibration phantom or of exactly knowing the dimensions of the calibration phantom.