Difference images for an axial slice (corresponding slice in Figure 1) through the liver: (a) PS-FBP, (b) PS-IR and (c) IR-FBP, image settings: window 69, level −990. Most notable differences between the reconstruction techniques are visible at the skin, bone structures (ribs, vertebrae) and in the surrounding air, in particular in comparison with PS. For homogeneous structures such as the liver, differences between IR and FBP images and between PS and FBP images. FBP, filtered back-projection; IR, iterative reconstruction; PS, PixelShine.