Figure 20. (a) Spin echo T₁ weighted coronal scan through the upper central incisors shows deviation of the midline to the left of the nasopalatine suture and the conchae of the nose. There is an arc shaped black line (arrowed) of cortical bone above the root apex of the upper left central incisor with a dark grey vertical line to it from its apex. (b) Short tau inversion recovery (STIR) sequence in the coronal plane at a comparative level to (a) shows a light grey spherical area (arrowed) of high signal at the apex of the upper left central incisor. The appearances of high signal on T₁ weighted and STIR images are typical of an inflammatory exudate indicating a chronic infection related to the upper left central incisor.