MRI: MR spectroscopy in tumours: 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 · MRI: MR spectroscopy in tumours

Sample item

Proton MR spectroscopy of an enhancing brain lesion shows a high choline peak, a markedly reduced N-acetylaspartate peak and a lactate peak. What does this pattern most strongly suggest?

AA simple arachnoid cystBA normal brain parenchymaCA high-grade neoplasm with membrane turnover and neuronal lossDA pure demyelinating plaque with preserved neurons

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

The answer and the reasoning

C. A high-grade neoplasm with membrane turnover and neuronal loss

Choline reflects cell membrane turnover and rises in tumours, while N-acetylaspartate is a neuronal marker that falls when neurons are replaced. Lactate appears with anaerobic metabolism in aggressive lesions.

Option by option

A. A simple arachnoid cyst
A cyst would show almost no brain metabolite peaks.
B. A normal brain parenchyma
Normal brain shows a dominant NAA peak with modest choline.
C. A high-grade neoplasm with membrane turnover and neuronal loss (correct)
Correct. High choline, low NAA and lactate favour an aggressive neoplasm.
D. A pure demyelinating plaque with preserved neurons
Demyelination can raise choline, but a marked fall in NAA with lactate favours tumour.

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, A high-grade neoplasm with membrane turnover and neuronal loss. Choline reflects cell membrane turnover and rises in tumours, while N-acetylaspartate is a neuronal marker that falls when neurons are replaced.

Why is "A simple arachnoid cyst" not the answer?

A cyst would show almost no brain metabolite peaks.

Why is "A normal brain parenchyma" not the answer?

Normal brain shows a dominant NAA peak with modest choline.

Why is "A pure demyelinating plaque with preserved neurons" not the answer?

Demyelination can raise choline, but a marked fall in NAA with lactate favours tumour.

What concept does this question test?

It tests MRI: MR spectroscopy in tumours in Radiology. Lactate appears with anaerobic metabolism in aggressive lesions.

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 MRI: MR spectroscopy in tumours?

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.