Imaging modalities and physics: arterial spin labelling: 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.

Try it

Radiology · Imaging modalities and physics: arterial spin labelling

Sample item

A patient with an eGFR of 10 mL/min needs MRI assessment of cerebral blood flow after a stroke. Which perfusion technique needs no injected contrast agent?

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

The answer and the reasoning

A. Arterial spin labelling

Arterial spin labelling magnetically labels the water in arterial blood and uses it as an endogenous tracer, so cerebral blood flow can be measured without gadolinium. It suits patients with severe renal impairment. The other methods all depend on a bolus of exogenous contrast.

Option by option

  • A. Arterial spin labelling (correct)

    Correct. Labelled arterial blood water acts as the tracer.

  • B. Dynamic contrast-enhanced T1 perfusion

    Dynamic contrast-enhanced perfusion also needs gadolinium.

  • C. Perfusion CT with iodinated contrast

    Perfusion CT needs an iodinated contrast bolus, which is a concern in renal failure.

  • D. Dynamic susceptibility contrast perfusion

    Dynamic susceptibility perfusion needs a gadolinium bolus.

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.

More Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is A, Arterial spin labelling. Arterial spin labelling magnetically labels the water in arterial blood and uses it as an endogenous tracer, so cerebral blood flow can be measured without gadolinium.

Why is "Dynamic contrast-enhanced T1 perfusion" not the answer?

Dynamic contrast-enhanced perfusion also needs gadolinium.

Why is "Perfusion CT with iodinated contrast" not the answer?

Perfusion CT needs an iodinated contrast bolus, which is a concern in renal failure.

Why is "Dynamic susceptibility contrast perfusion" not the answer?

Dynamic susceptibility perfusion needs a gadolinium bolus.

What concept does this question test?

It tests Imaging modalities and physics: arterial spin labelling in Radiology. It suits patients with severe renal impairment. The other methods all depend on a bolus of exogenous contrast.

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: arterial spin labelling?

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.