A scanning-based radiation detector apparatus for recording a two-dimensional image of an object comprising: - a one-dimensional detector unit exposed to a fan-shaped beam of ionizing radiation, as transmitted through or scattered off said object, and arranged for repeated one-dimensional imaging of said fan-shaped beam of ionizing radiation, said fan-shaped beam of ionizing radiation having a thickness when impinging on said one-dimensional detector unit; and - a device (17-19, 21-22) for moving said one-dimensional detector unit and said fan-shaped beam of ionizing radiation relative said object while said one-dimensional detector unit is arranged to repeatedly detect to thereby create a two-dimensional image of the object, wherein - said device for moving comprises a spindle approximately at the height of the X-ray tube 11, around which said one-dimensional detector unit and said fan-shaped beam of ionizing radiation can be moved relative said object in a pivoting movement while said one-dimensional detector unit is arranged to repeatedly detect, said one-dimensional detector unit comprising a line-shaped sensitive area and said spindle being parallel with the long side of the line-shaped sensitive area and with the long side of the cross-sectional area of the fan-shaped beam, characterized in that - said one-dimensional detector unit has an ionizing radiation sensitive thickness (dt), which is smaller than the thickness of said fan-shaped beam of ionizing radiation; and - said apparatus comprises a control device for controlling the repeated detections by said one-dimensional detector unit such that the moved distance between two subsequent recordings of one-dimensional images of said fan-shaped beam of ionizing radiation is not lower than essentially half the ionizing radiation sensitive thickness (dt) of said one-dimensional detector unit, but lower than the ionizing radiation sensitive thickness (dt) of said one-dimensional detector unit, when entering the one-dimensional detector unit. - a one-dimensional detector unit exposed to a fan-shaped beam of ionizing radiation, as transmitted through or scattered off said object, and arranged for repeated one-dimensional imaging of said fan-shaped beam of ionizing radiation, said fan-shaped beam of ionizing radiation having a thickness when impinging on said one-dimensional detector unit; and - a device (17-19, 21-22) for moving said one-dimensional detector unit and said fan-shaped beam of ionizing radiation relative said object while said one-dimensional detector unit is arranged to repeatedly detect to thereby create a two-dimensional image of the object, wherein - said device for moving comprises a spindle approximately at the height of the X-ray tube 11, around which said one-dimensional detector unit and said fan-shaped beam of ionizing radiation can be moved relative said object in a pivoting movement while said one-dimensional detector unit is arranged to repeatedly detect, said one-dimensional detector unit comprising a line-shaped sensitive area and said spindle being parallel with the long side of the line-shaped sensitive area and with the long side of the cross-sectional area of the fan-shaped beam, characterized in that - said one-dimensional detector unit has an ionizing radiation sensitive thickness (dt), which is smaller than the thickness of said fan-shaped beam of ionizing radiation; and - said apparatus comprises a control device for controlling the repeated detections by said one-dimensional detector unit such that the moved distance between two subsequent recordings of one-dimensional images of said fan-shaped beam of ionizing radiation is not lower than essentially half the ionizing radiation sensitive thickness (dt) of said one-dimensional detector unit, but lower than the ionizing radiation sensitive thickness (dt) of said one-dimensional detector unit, when entering the one-dimensional detector unit.