Figure 13. Caecal diverticulitis. (a) Inflammatory changes surrounding caecum and appendix (large arrow). Note that although the appendiceal wall is thickened, "clean" air is noted within it (small arrow). (b) CT image slightly superior to (a) demonstrates similar changes adjacent to an inflamed diverticulum (arrow). Note that the diverticulum rather then the appendix is situated at the centre of the changes.