Figure 4. A 74-year-old male patient, who received radiotherapy to the pelvic region due to metastatic lung cancer, presented with abdominal pain and distension. In the dual-energy IV contrast abdominopelvic examination, loss of integrity in the distal ileal wall and free air in the abdominal cavity were observed. However, the contrast difference between the wall of the intestinal segment with disrupted wall integrity and the adjacent bowel loops was less than in other perforation patients. It was thought to be because of radiotherapy.

Transmural loss of wall enhancement on (a) 45 keV virtual monoenergetic images (white arrow) and (b) iodine overlay map images (white arrow). (c) Perforation localization in the ileum after radiotherapy.