Gangrenous Appendicitis

gangrenous appendix

This 71 year-old male had an abdominal CT for investigation of septicaemia and right upper quadrant tenderness. The oblique coronal image shows fat stranding around a gas-filled and distended appendix (large arrow) and extraluminal gas adjacent to it (arrowheads). There was a faecolith at the appendix base (not shown). The findings are consistent with perforation of a gangrenous appendix.

Gas within the appendix is usually a sign of normality. This case clearly shows that this is not always true. Extraluminal gas has been evaluated along with four other findings for the assessment of perforation: extraluminal appendicolith, abscess, phlegmon, and a defect in the enhancing appendiceal wall. Each of these findings have a high specificity but a low sensitivity. By looking for all findings rather than just one, the sensitivity for perforation can be increased to 95%. The implication of this is that if one finding is present, perforation is likely, and if all are absent, perforation is unlikely.

Horrow MM, White DS, Horrow JC. Differentiation of Perforated from Nonperforated Appendicitis at CT. Radiology 2003;227:46-51

Credit: Dr Laughlin Dawes