Imaging Case of the Week 398 Answer

The supine abdominal x-ray shows 2 findings.

  1. Lucency over the liver which should not be seen unless there is a pneumoperitoneum.
  2. Falciform ligament sign – the falciform ligament is an embryological remnant of the umbilical artery that connects the liver to the anterior abdominal wall. The ligament is not visible under normal circumstances. When surrounded by free peritoneal air, the ligament is visible as a dense vertical band in the right upper quadrant.

CT scan of the abdomen revealed a perforated gastric ulcer as the cause of pneumoperitoneum.

Reference: Fundamentals of Diagnostic Radiology by Brant and Helms.