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Case of the Week 383

What sign is depicted on this image?

  • 45 year-old with abdominal pain

Contrast-enhanced axial CT of lower abdomen

1. Small bowel feces sign
2. Misty mesentery sign
3. Accordion sign
4. Duplicated ureter sign
5. Target sign

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Additional Images






5. Target Sign



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Target Sign

General Considerations

  • Three concentric circles formed by the layers of the bowel wall in inflammatory disease of the bowel and seen on contrast-enhanced CT
  • The inner and outer rings of high attenuation are presumed to represent hyperemia of the mucosa and muscularis propia and/or serosa, respectively
  • The middle low attenuation ruing is presumed to represent submucosal edema which produces thickening of the bowel wall
  • Best seen during late arterial, early venous phase

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is an award-winning educational website aimed primarily at medical students and radiology residents-in-training, containing  lectures, handouts, images, Cases of the Week, archives of cases, quizzes, flashcards of differential diagnoses and “most commons” lists, primarily in the areas of chest, GI, GU cardiac, bone and neuroradiology.