Chest and cardiac imaging: AP film and heart size: 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 · Chest and cardiac imaging: AP film and heart size

Sample item

A bedridden ICU patient has a supine AP chest film with a cardiothoracic ratio of 0.58 and clear lungs. What is the most appropriate interpretation?

ADefinite cardiomegaly that needs diureticsBA normal heart because the ratio on AP films is always higherCHeart size cannot be judged reliably because AP projection magnifies the heart, so correlate with echocardiography or a PA filmDPericardial effusion because the ratio exceeds 0.5

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

The answer and the reasoning

C. Heart size cannot be judged reliably because AP projection magnifies the heart, so correlate with echocardiography or a PA film

In an AP film the heart lies farther from the detector and is magnified, and supine positioning adds further change. A ratio above 0.5 therefore does not prove cardiomegaly. Echocardiography or an erect PA film gives a dependable assessment.

Option by option

A. Definite cardiomegaly that needs diuretics
Treating on this film alone risks overdiagnosis of cardiac enlargement.
B. A normal heart because the ratio on AP films is always higher
A normal heart cannot be declared; the film simply cannot answer the question.
C. Heart size cannot be judged reliably because AP projection magnifies the heart, so correlate with echocardiography or a PA film (correct)
Correct. AP magnification makes heart size unreliable.
D. Pericardial effusion because the ratio exceeds 0.5
A raised ratio is non-specific and does not indicate effusion.

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 C, Heart size cannot be judged reliably because AP projection magnifies the heart, so correlate with echocardiography or a PA film. In an AP film the heart lies farther from the detector and is magnified, and supine positioning adds further change.

Why is "Definite cardiomegaly that needs diuretics" not the answer?

Treating on this film alone risks overdiagnosis of cardiac enlargement.

Why is "A normal heart because the ratio on AP films is always higher" not the answer?

A normal heart cannot be declared; the film simply cannot answer the question.

Why is "Pericardial effusion because the ratio exceeds 0.5" not the answer?

A raised ratio is non-specific and does not indicate effusion.

What concept does this question test?

It tests Chest and cardiac imaging: AP film and heart size in Radiology. A ratio above 0.5 therefore does not prove cardiomegaly. Echocardiography or an erect PA film gives a dependable assessment.

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 Chest and cardiac imaging: AP film and heart size?

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.