Abdominal imaging: psoas shadow: 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 · Abdominal imaging: psoas shadow

Sample item

On a plain abdominal radiograph, the left psoas muscle outline is lost while the right is clearly seen. In an unwell patient, which condition is the best consideration?

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

The answer and the reasoning

D. Retroperitoneal collection or haematoma on the left

The psoas outline is visible because of retroperitoneal fat on either side, and a fluid collection, abscess or haemorrhage in the retroperitoneum obliterates it. Technical factors and scoliosis can also alter the shadows.

Option by option

  • A. Pneumoperitoneum

    Pneumoperitoneum is shown by gas under the diaphragm.

  • B. Normal variant in all patients

    Loss of a psoas margin is not simply a normal variant in a sick patient.

  • C. Mild constipation

    Constipation does not obliterate the psoas shadow.

  • D. Retroperitoneal collection or haematoma on the left (correct)

    Correct. Loss of one psoas margin suggests a retroperitoneal process.

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 D, Retroperitoneal collection or haematoma on the left. The psoas outline is visible because of retroperitoneal fat on either side, and a fluid collection, abscess or haemorrhage in the retroperitoneum obliterates it.

Why is "Pneumoperitoneum" not the answer?

Pneumoperitoneum is shown by gas under the diaphragm.

Why is "Normal variant in all patients" not the answer?

Loss of a psoas margin is not simply a normal variant in a sick patient.

Why is "Mild constipation" not the answer?

Constipation does not obliterate the psoas shadow.

What concept does this question test?

It tests Abdominal imaging: psoas shadow in Radiology. Technical factors and scoliosis can also alter the shadows.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Abdominal imaging: psoas shadow?

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.