A computed tomography scanning system or recording computed tomography image data of an object in an object area comprising: - an X-ray source and an X-ray detector arranged at either side of the object area, the X-ray source having a flying focal spot from which X-rays are emitted and the X-ray detector comprising pixels arranged in at least one row for recording images of the object, and - a device provided for rotating said X-ray source and said X-ray detector with respect to said object around an axis of rotation which is substantially perpendicular to the at least one row of pixels, while the at least one row of pixel record images of the object, wherein - the X-ray source comprises means for moving the flying focal spot of the X-ray source from an original position and in a direction essentially opposite to the direction the X-ray source moves during the rotation, characterized in that - said X-ray detector is provided with means for time delay summation such that pixel signal values of the at least one row of pixels are shifted one pixel and summed with pixel signal values obtained in a following recording of an image, wherein the shifting and summing of pixel signal values are performed repeatedly and the pixel signal values are shifted in a direction essentially opposite to the direction the X-ray detector moves during the rotation, and - the means for moving the flying focal spot is provided for moving the flying focal spot and the means for time delay summation is provided for the repeated shifting and summing of pixel signal values during recurrent first periods of said rotation, after each of which first periods, during a second period of said rotation, the means for moving is provided for moving the flying focal spot back to its original position and the X-ray detector is provided for reading out the pixel signal values. - an X-ray source and an X-ray detector arranged at either side of the object area, the X-ray source having a flying focal spot from which X-rays are emitted and the X-ray detector comprising pixels arranged in at least one row for recording images of the object, and - a device provided for rotating said X-ray source and said X-ray detector with respect to said object around an axis of rotation which is substantially perpendicular to the at least one row of pixels, while the at least one row of pixel record images of the object, wherein - the X-ray source comprises means for moving the flying focal spot of the X-ray source from an original position and in a direction essentially opposite to the direction the X-ray source moves during the rotation, characterized in that - said X-ray detector is provided with means for time delay summation such that pixel signal values of the at least one row of pixels are shifted one pixel and summed with pixel signal values obtained in a following recording of an image, wherein the shifting and summing of pixel signal values are performed repeatedly and the pixel signal values are shifted in a direction essentially opposite to the direction the X-ray detector moves during the rotation, and - the means for moving the flying focal spot is provided for moving the flying focal spot and the means for time delay summation is provided for the repeated shifting and summing of pixel signal values during recurrent first periods of said rotation, after each of which first periods, during a second period of said rotation, the means for moving is provided for moving the flying focal spot back to its original position and the X-ray detector is provided for reading out the pixel signal values.