X-ray physics: 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 · X-ray physics

Sample item

As a polychromatic X-ray beam traverses dense tissue, low-energy photons are preferentially absorbed so that the mean energy of the beam rises, causing cupping artefact on CT. What is this phenomenon?

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

The answer and the reasoning

C. Beam hardening

Filtering of soft photons by the patient makes the remaining beam more penetrating, producing dark streaks and cupping. It is reduced by filtration and correction algorithms.

Option by option

  • A. Photon starvation

    Photon starvation is insufficient photons reaching the detector.

  • B. Compton scatter

    Compton scatter is deflection of photons with energy loss.

  • C. Beam hardening (correct)

    Correct. Preferential removal of soft photons raises average beam energy.

  • D. Partial volume averaging

    Partial volume averaging mixes tissues within one voxel.

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.

More Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is C, Beam hardening. Filtering of soft photons by the patient makes the remaining beam more penetrating, producing dark streaks and cupping.

Why is "Photon starvation" not the answer?

Photon starvation is insufficient photons reaching the detector.

Why is "Compton scatter" not the answer?

Compton scatter is deflection of photons with energy loss.

Why is "Partial volume averaging" not the answer?

Partial volume averaging mixes tissues within one voxel.

What concept does this question test?

It tests X-ray physics in Radiology. It is reduced by filtration and correction algorithms.

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 X-ray physics?

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.