Radiation protection: ALARA and justification: 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: ALARA and justification

Sample item

A clinician requests a CT abdomen in a 25-year-old woman with mild uncomplicated abdominal pain for the third time in a month, with a normal ultrasound. Which principle is most relevant for the radiologist?

ANo justification is needed since CT is accurateBJustification of the exposure, with ultrasound or MRI considered if appropriateCDose limitation applies, so the patient dose limit is 1 mSv per yearDOccupational limit applies to the patient

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

The answer and the reasoning

B. Justification of the exposure, with ultrasound or MRI considered if appropriate

Medical exposures must be justified, optimised and are not subject to dose limits, because the individual benefit must outweigh the risk. Repeated CT without clear indication is not justified. Alternatives without ionising radiation should be considered, particularly in young patients.

Option by option

A. No justification is needed since CT is accurate
Accuracy does not replace the need for justification.
B. Justification of the exposure, with ultrasound or MRI considered if appropriate (correct)
Correct. Justification and use of alternatives are the guiding principles.
C. Dose limitation applies, so the patient dose limit is 1 mSv per year
Dose limits do not apply to medical exposures of patients.
D. Occupational limit applies to the patient
Occupational limits apply to workers, not to patients.

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.

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is B, Justification of the exposure, with ultrasound or MRI considered if appropriate. Medical exposures must be justified, optimised and are not subject to dose limits, because the individual benefit must outweigh the risk.

Why is "No justification is needed since CT is accurate" not the answer?

Accuracy does not replace the need for justification.

Why is "Dose limitation applies, so the patient dose limit is 1 mSv per year" not the answer?

Dose limits do not apply to medical exposures of patients.

Why is "Occupational limit applies to the patient" not the answer?

Occupational limits apply to workers, not to patients.

What concept does this question test?

It tests Radiation protection: ALARA and justification in Radiology. Repeated CT without clear indication is not justified. Alternatives without ionising radiation should be considered, particularly in young patients.

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 Radiation protection: ALARA and justification?

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.