Radiological signs of pneumoperitoneum in an extremely low birthweight infant.

To cite: Raturi S, Chandran S, James TE-leong H, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014205510 DESCRIPTION A twin male infant weighing 820 g was born at 26 weeks of gestation. At birth he received mechanical ventilation, surfactant and subsequently indomethacin treatment for a large patent ductus arteriosus. On day 8 of life he had frequent episodes of desaturations. Transillumination of the chest was negative. Abdominal examination and laboratory studies were unremarkable. Chest and abdominal radiographs showed signs of pneumoperitoneum. These included presence of subdiaphragmatic air in the right upper quadrant, Rigler’s sign, falciform ligament sign, cupola sign and scrotal air (figures 1 and 2). An emergency laparotomy revealed an isolated perforation of jejunum, which was repaired. Rigler’s sign—Double wall or bas-relief sign, first described by Leo Rigler, where both outer and inner walls of the bowel wall can be visualised when there is air in the peritoneal cavity and within the intestinal lumen. Avariant of Rigler’s sign occurs where the outside of the bowel wall is visible because the lumen is filled with fluid. A pseudo-double wall sign is produced when two loops of distended bowel are adjacent to each other and their adjoining wall are outlined by intraluminal gas in both loops. Falciform ligament sign (Silver sign)—Falciform ligament appears as a linear density running parallel to the right border of the spine when free air lies on either side of it. Cupola sign (Lord Nelson’s hat sign)—Inverted cup-shaped arcuate lucency seen in supine radiographs within the median subphrenic space.