Figure 1

Axial computed tomography image with oral and intravenous contrast at the level of S1 demonstrating a giant colonic diverticulum*. The wall of the diverticulum and the surrounding fat are thickened denoting recent inflammation. Note the relationship to the left external and internal iliac vessels (arrows A and B, respectively). The obturator nerve (L2–4) emerges from the medial aspect of the psoas muscle and runs downwards and forwards, deep into [the internal iliac vessels.