A method (100, 200, 300) for finding a second positioning (270_1, 270_2, 270_n) of an object relative to a CT scan of the object, comprising the steps of: performing or simulating the CT scan (110, 210, 212) for a first positioning to obtain one or more radiographs for the first positioning; reconstructing (120, 220, 222) a CT reconstruction of the object on the basis of the one or more radiographs for the first positioning to obtain a first data model (235, 235_1); locally evaluating (130, 230, 232) an image quality for one or more local regions of the first data model to obtain one or more image quality values for the one or more local regions; judging (140, 150, 240, 250) the image quality for the CT reconstruction or a regional region of the CT reconstruction using the one or more image quality values; determining the second positioning of the object relative to the CT scan; and repeating the steps of performing or simulating the CT scan (110, 210, 212), reconstructing (120, 220, 222), locally evaluating (130, 230, 232), judging and determining for the second positioning while changing the second positioning; characterized in that the step of locally evaluating (130, 230, 232) comprises the sub-step of adding up intensity values per local region from the one or more radiographs for the first positioning, wherein a high intensity value results in a high image quality value per local region; or characterized in that the step of locally evaluating (130, 230, 232) comprises the sub-step of simulating a CT reconstruction of the object and the sub-step of comparing the simulated CT reconstruction to the CT reconstruction of the object, wherein a high match between the simulated CT reconstruction and the CT reconstruction results in a high image quality value per local region. performing or simulating the CT scan (110, 210, 212) for a first positioning to obtain one or more radiographs for the first positioning; reconstructing (120, 220, 222) a CT reconstruction of the object on the basis of the one or more radiographs for the first positioning to obtain a first data model (235, 235_1); locally evaluating (130, 230, 232) an image quality for one or more local regions of the first data model to obtain one or more image quality values for the one or more local regions; judging (140, 150, 240, 250) the image quality for the CT reconstruction or a regional region of the CT reconstruction using the one or more image quality values; determining the second positioning of the object relative to the CT scan; and repeating the steps of performing or simulating the CT scan (110, 210, 212), reconstructing (120, 220, 222), locally evaluating (130, 230, 232), judging and determining for the second positioning while changing the second positioning; characterized in that the step of locally evaluating (130, 230, 232) comprises the sub-step of adding up intensity values per local region from the one or more radiographs for the first positioning, wherein a high intensity value results in a high image quality value per local region; or characterized in that the step of locally evaluating (130, 230, 232) comprises the sub-step of simulating a CT reconstruction of the object and the sub-step of comparing the simulated CT reconstruction to the CT reconstruction of the object, wherein a high match between the simulated CT reconstruction and the CT reconstruction results in a high image quality value per local region.