Accordion sign (colon)

The accordion sign (also known as concertina sign) is seen on CT examinations of the abdomen and refers to the similarity between the thickened oedematous wall of pseudomembranous colitis and the folds of an accordion. This appearance is the result of hyperaemic enhancing mucosa stretched over markedly thickened submucosal folds and is also seen when contrast is trapped between oedematous haustral folds and pseudomembranes formed on the luminal surface of the colon 2.

Although it has been reported to be a specific sign of severe Clostridium difficile related-colitis, it has also been described in other forms of non-specific, ischaemic, and non-Clostridial infective colitides 1.

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Article information

rID: 7305
Section: Signs
Tag: stub, cases, refs
Synonyms or Alternate Spellings:
  • Accordion sign in pseudomembaneous colitis
  • Concertina sign

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Cases and figures

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    Figure 1: accordion (the middle bellows resemble colitic bowel)
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    Case 1
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    Case 2
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    Case 3: accordion sign along transverse colon on abdominal radiograph
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