Radiation protection: dose area product: 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 · Radiation protection: dose area product

Sample item

In a long fluoroscopically guided procedure, which quantity displayed on the console is used to monitor the total radiation delivered to the patient?

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

The answer and the reasoning

A. Dose area product, in Gy per square centimetre

Dose area product is the air kerma multiplied by the area of the beam and is measured by a chamber at the tube. It is used for patient dose audit and as a guide to stochastic risk and to skin injury risk in interventional work.

Option by option

  • A. Dose area product, in Gy per square centimetre (correct)

    Correct. DAP measures total radiation output and is shown on fluoroscopy units.

  • B. Half value layer in millimetres of aluminium

    Half value layer describes beam quality.

  • C. Signal to noise ratio

    Signal to noise ratio describes image quality, not dose.

  • D. Hounsfield units

    Hounsfield units describe CT attenuation.

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 A, Dose area product, in Gy per square centimetre. Dose area product is the air kerma multiplied by the area of the beam and is measured by a chamber at the tube.

Why is "Half value layer in millimetres of aluminium" not the answer?

Half value layer describes beam quality.

Why is "Signal to noise ratio" not the answer?

Signal to noise ratio describes image quality, not dose.

Why is "Hounsfield units" not the answer?

Hounsfield units describe CT attenuation.

What concept does this question test?

It tests Radiation protection: dose area product in Radiology. It is used for patient dose audit and as a guide to stochastic risk and to skin injury risk in interventional work.

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 Radiation protection: dose area product?

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.