A method is disclosed for scanning a cyclically moved examination object using a contrast agent within the scope of a preliminary examination by way of a CT scanner, in which measurement data is recorded at a sequence of recording times. A first image is reconstructed at every recording time from the measurement data, from which a time profile of a concentration of the contrast agent is established. The recording times for respectively recording a certain phase of the motion are synchronized with a motion signal from the examination object. A second image with a time offset with respect to the first image is reconstructed from the measurement data at each recording time. A motion curve representing a time profile of an intensity of the cyclical motion is established by comparing the first image and the second image at each recording time.