Method and system for determining at least one projection parameter of a CT system

Abstract

The invention relates to a system and a method for determining at least one projection parameter (P) of a CT device (2), comprising the steps: a. Providing a first transmission image (T1) of an object (6) with a first relative position between the CT device (2) and the object (6), b. Providing a further transmission image (T2) of the object (6) with a further relative position between the CT device (2) and the object (6), c. Determining at least one epipolar plane (E), d.Determining a first value as the value of an integral over a derivative of attenuation values ​​of the first transmission image (T1) along an intersection line of the epipolar plane (E) with an image plane of the first transmission image (T1) and at least one further value as the value of an integral over a derivative of the attenuation values ​​of the further transmission image (T2) along an intersection line of the epipolar plane (E) with an image plane of the further transmission image (T2).Determining at least one projection parameter (P) as a function of a difference in value (D) between the first and the further value, wherein the first and the further value are each determined as the value of an integral over the derivative of the attenuation values ​​along a half-line starting at the epipole (EP1, EP2, EP11, EP12, EP21, EP22) and intersecting the imaged object (6), wherein all sections of the imaged object (6) intersected by the half-line are completely imaged in the transmission image (T1, T2).

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