Radiological Signs of Intestinal Pathologies

Signs and Their Associations

The comb sign, characterized by prominent vasa recta, is associated with active inflammation in Crohn's disease, particularly with perienteric edema/inflammation and increased attenuation in mesenteric fat on CT, as recommended by the American Gastroenterological Association 1, 2
The accordion sign, appearing as marked thickening of haustral folds with contrast material trapped between them, is characteristic of pseudomembranous colitis caused by Clostridium difficile infection, according to the American Gastroenterological Association 2, 3, 4
Rigler's sign, or the double wall sign, indicates pneumoperitoneum from bowel perforation, as outlined by the American College of Radiology 1, 3
The comb sign indicates active inflammation in Crohn's disease and should prompt careful evaluation for other signs of severe disease, including wall thickening, ulcerations, and penetrating complications, as suggested by the Crohn's and Colitis Foundation 1, 2
MR enterography or CT enterography should assess for asymmetric mesenteric border inflammation, which is highly specific for Crohn's disease, as recommended by the American Gastroenterological Association 3, 4

Additional findings to report in Crohn's disease include fibrofatty proliferation ("creeping fat"), strictures, and fistulas, according to the American Gastroenterological Association 1