Imaging modalities and physics: lateral resolution: 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 · Imaging modalities and physics: lateral resolution

Sample item

A sonographer needs to separate two small cysts lying side by side across the beam at a fixed depth in the liver. Which adjustment most directly improves this separation?

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

The answer and the reasoning

C. Placing the transmit focus at the depth of the cysts

Lateral resolution depends on beam width, which is narrowest at the focus, so focusing at the target depth sharpens separation across the beam. Pulse length governs axial resolution, and gain only changes brightness. Pulse repetition frequency alters frame rate and aliasing, not beam width.

Option by option

  • A. Lengthening the transmitted pulse

    A longer pulse worsens axial resolution along the beam, not side by side separation.

  • B. Raising the overall receiver gain

    Gain amplifies echoes and brightens the image without narrowing the beam.

  • C. Placing the transmit focus at the depth of the cysts (correct)

    Correct. Narrowing the beam at the focus improves lateral resolution.

  • D. Increasing the pulse repetition frequency

    Pulse repetition frequency changes the frame rate and the depth or velocity range, not the beam width.

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 C, Placing the transmit focus at the depth of the cysts. Lateral resolution depends on beam width, which is narrowest at the focus, so focusing at the target depth sharpens separation across the beam.

Why is "Lengthening the transmitted pulse" not the answer?

A longer pulse worsens axial resolution along the beam, not side by side separation.

Why is "Raising the overall receiver gain" not the answer?

Gain amplifies echoes and brightens the image without narrowing the beam.

Why is "Increasing the pulse repetition frequency" not the answer?

Pulse repetition frequency changes the frame rate and the depth or velocity range, not the beam width.

What concept does this question test?

It tests Imaging modalities and physics: lateral resolution in Radiology. Pulse length governs axial resolution, and gain only changes brightness. Pulse repetition frequency alters frame rate and aliasing, not beam width.

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 Imaging modalities and physics: lateral resolution?

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.