GI imaging: comb sign in Crohn disease: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Radiology · GI imaging: comb sign in Crohn disease

Sample item

In active Crohn disease, CT enterography shows prominent engorged vasa recta of the mesentery perpendicular to a thickened ileal segment. What is this sign?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Comb sign

In active inflammation, vasa recta become engorged and appear like the teeth of a comb along the mesenteric border of the diseased bowel, and it is accompanied by fibrofatty proliferation, called creeping fat. It indicates active, not fibrotic, disease.

Option by option

  • A. String sign

    The string sign is a barium finding of a narrowed terminal ileum.

  • B. Whirlpool sign

    The whirlpool sign is that of midgut volvulus.

  • C. Comb sign (correct)

    Correct. Engorged vasa recta are the comb sign of active Crohn disease.

  • D. Target sign of intussusception

    The target sign is of intussusception.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is C, Comb sign. In active inflammation, vasa recta become engorged and appear like the teeth of a comb along the mesenteric border of the diseased bowel, and it is accompanied by fibrofatty proliferation, called creeping fat.

Why is "String sign" not the answer?

The string sign is a barium finding of a narrowed terminal ileum.

Why is "Whirlpool sign" not the answer?

The whirlpool sign is that of midgut volvulus.

Why is "Target sign of intussusception" not the answer?

The target sign is of intussusception.

What concept does this question test?

It tests GI imaging: comb sign in Crohn disease in Radiology. It indicates active, not fibrotic, disease.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study GI imaging: comb sign in Crohn disease?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.