The present invention relates to a method for preparing an X-ray image, which can be carried out by an X-ray machine, of at least one surface and/or volume area of at least one part of at least one head of at least one patient. The invention also relates to a corresponding device for data processing, a corresponding computer program product, a corresponding medium and a corresponding X-ray machine. The invention also relates to a method for taking an X-ray image which can be carried out by an X-ray machine of at least one surface and/or volume area of at least one part of at least one head of at least one patient.