Radiotherapy and nuclear medicine basics: sestamibi redistribution: 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 · Radiotherapy and nuclear medicine basics: sestamibi redistribution

Sample item

In a Tc-99m sestamibi myocardial perfusion study, separate injections are given for stress and rest imaging. What is the reason?

AIt is cleared by the kidney within minutesBIt is taken up only by ischaemic myocardiumCThere is little redistribution after myocardial uptakeDIt redistributes rapidly and masks the stress defect

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

The answer and the reasoning

C. There is little redistribution after myocardial uptake

Sestamibi is a lipophilic cation retained by mitochondria in viable myocytes with minimal redistribution, so the stress image reflects the distribution at injection. A second injection is needed for rest images, unlike thallium, which redistributes.

Option by option

A. It is cleared by the kidney within minutes
Sestamibi is cleared by the hepatobiliary route over hours, not by the kidney within minutes.
B. It is taken up only by ischaemic myocardium
Sestamibi is taken up in proportion to perfusion in viable myocardium, not only in ischaemic areas.
C. There is little redistribution after myocardial uptake (correct)
Correct. Minimal redistribution fixes the tracer distribution at injection, so rest imaging needs a second dose.
D. It redistributes rapidly and masks the stress defect
Rapid redistribution describes thallium and is the reason it needs only one injection.

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, There is little redistribution after myocardial uptake. Sestamibi is a lipophilic cation retained by mitochondria in viable myocytes with minimal redistribution, so the stress image reflects the distribution at injection.

Why is "It is cleared by the kidney within minutes" not the answer?

Sestamibi is cleared by the hepatobiliary route over hours, not by the kidney within minutes.

Why is "It is taken up only by ischaemic myocardium" not the answer?

Sestamibi is taken up in proportion to perfusion in viable myocardium, not only in ischaemic areas.

Why is "It redistributes rapidly and masks the stress defect" not the answer?

Rapid redistribution describes thallium and is the reason it needs only one injection.

What concept does this question test?

It tests Radiotherapy and nuclear medicine basics: sestamibi redistribution in Radiology. A second injection is needed for rest images, unlike thallium, which redistributes.

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 Radiotherapy and nuclear medicine basics: sestamibi redistribution?

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.