1. A scanning-based radiation detector arrangement for two-dimensional imaging of an object comprising a plurality of one-dimensional detector units, each comprising an entrance slit, through which ionizing radiation, as transmitted through said object, is entered, and being adapted for one-dimensional imaging, wherein said plurality of one-dimensional detector units are arranged in an array with their respective entrance slits facing a source of the ionizing radiation; and said scanning-based detector arrangement includes a rotating device adapted to rotate said array of one-dimensional detector units relative said object in a plane substantially perpendicular to a direction of the ionizing radiation, while the plurality of one-dimensional detector units are arranged to repeatedly detect, hence creating a series of two-dimensional images of the object.