Computer-implemented method for x-ray imaging with varying x-ray dose

A computer program comprising computer-readable code which, when executed by a computer-assisted x-ray cone beam imaging system, causes the said system to perform a method for generating a two dimensional final image of at least a sub region of the maxillofacial region of a patient with x-ray cone beam CT, the method comprising the steps of:

• defining a position and alignment of the 2D final image to be generated relative to said sub region of the dental maxillofacial region of the patient, wherein the 2D final image essentially being identical to a x-ray projection image of said sub region with parallel beam geometry;
• acquiring a plurality of x-ray projection images by rotating an x-ray source and an x-ray detector around the head of the patient, wherein the x-ray source and the x-ray detector are configured for a x-ray cone beam CT image acquisition;
• varying, during the acquisition step, the amounts of x-ray doses used for the acquisition of each of the x-ray projection images such that
• a total amount of the x-ray dose is increased above a predetermined level for the x-ray projection images that are acquired when the projection direction is within a first predetermined range of angles centered about a first direction which is parallel to the normal direction of the 2D final image to be generated, and
• a total amount of the x-ray dose is reduced below the predetermined level for the x-ray projection images that are acquired when the projection direction is within a second predetermined range of angles centered about a second direction which is perpendicular to the normal direction of the 2D final image to be generated;
• generating the 2D final image as a virtual projection with parallel x-ray beam geometry of the sub region of the maxillofacial region of a patient by using the x-ray projection images acquired.