The present invention relates to positioning of an X-ray imaging system. In order to provide an improved relative positioning of the X-ray imaging system for spine interventions, a device (10) for positioning of an X-ray imaging system is provided. The device comprises a data storage unit (12), a processing unit (14) and an output unit (16). The data storage unit is configured to store and provide 3D image data (18) of a spine region of interest of a subject comprising a part of a spine structure, the spine structure comprising at least one vertebra. The processing unit is configured to select at least one vertebra of the spine structure as target vertebra； to segment at least the target vertebra in the 3D image data； wherein the segmentation comprises identifying at least one anatomic feature of the target vertebra； to define a position of a predetermined reference line based on a spatial arrangement of the at least one anatomic feature； and to determine a target viewing direction of an X-ray imaging system based on the reference line. The output unit is configured to provide the target viewing direction for an X-ray imaging system.
