Figure 2c. (a) Abdominal CT scan obtained at the level of the celiac trunk demonstrates a 10 x 8-cm abscess cavity containing a large amount of gas (arrowhead) and a smaller amount of fluid (arrows). An irregularly shaped collection of gas and fluid is seen within the liver straddling the midline. Inflammatory changes are present in the adjacent peritoneal fat anterior to the liver. (b) CT scan obtained at the level of the origin of the superior mesenteric artery reveals a complex collection of gas and fluid divided into two compartments. (c) CT scan shows extension of the abscess cavity into segment IV of the liver. The cavity is seen reaching the hepatic surface adjacent to the proximal duodenum.