A method for intra-operative calibration of C-arm X-ray devices

The invention relates to an X-ray examination device and a method for producing undistorted X-ray images. The aim of the invention is to provide a means of calculating the characteristics of the image and for correcting distortions. To this end, at least one calibration body (7, 8) is arranged for producing a reference pattern and a correction unit (13) is used to correct the distortions in X-ray images using the pattern actually produced by the calibration bodies (7, 8) when the patient is X-rayed (fig. 4) and the reference pattern that is calculated.