Fig. 4.

a–c A patient with an accessory facet joint ossicle. In the axial plane this is easily seen using a bone algorithm and bone windows for display (a). Using a soft tissue algorithm for reconstruction and bone windows for display, the lesion is hard to visualise (b). Using a soft tissue reconstruction algorithm and soft tissue windows for display, the lesion is invisible (c). Images should routinely be reconstructed with a sharp (for bone and lung) and soft (for soft tissues) algorithm and be displayed with appropriate window settings