Figure 6. A 31-year-old female patient treated for metastatic colon cancer developed abdominal pain and distension, and free air (black arrows) was observed in the perihepatic area on dual-energy abdominopelvic CT with IV contrast. Perforation focus was not detected on CT examination.

(a) Axial image. (b) Coronal image. (c) No perforation was found in the patient who underwent laparotomy due to free air in the abdomen.