1. A computed tomography method, comprising: generating radiation by a radiation source; irradiating an examination object with the radiation from different projection directions; bombarding a detector with the radiation; capturing projection images of the examination object by the detector; determining a number of contour points describing an outline contour of the examination object for the different projection directions based on the projection images in an object image space; searching the contour points of each of the different projection directions for a contour point having a minimum distance from the detector; setting a width of an airgap between the detector and the examination object for the each of the contour points having the minimum distance; performing a scattered radiation correction for the projection images taking into account the airgap; and, reconstructing an object image of the examination object in the object image space based on the corrected projection images.