Radiotherapy and nuclear medicine basics: FDG urinary excretion: 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: FDG urinary excretion

Sample item

An FDG PET-CT is requested to stage cervical cancer, but intense tracer activity in the bladder obscures the pelvis. Which measure helps?

AStopping the scan and using a gamma cameraBGiving oral glucose before imagingCHydration, diuretic and voiding, or delayed imagesDIncreasing the injected FDG dose

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

The answer and the reasoning

C. Hydration, diuretic and voiding, or delayed images

FDG is excreted in urine and accumulates in the bladder, hiding pelvic disease. Hydration, a diuretic, voiding before imaging, bladder catheterisation or delayed images reduce this problem.

Option by option

A. Stopping the scan and using a gamma camera
A gamma camera cannot perform coincidence PET imaging and does not fix bladder activity.
B. Giving oral glucose before imaging
Oral glucose competes with FDG and lowers tumour uptake.
C. Hydration, diuretic and voiding, or delayed images (correct)
Correct. Promoting clearance of urinary activity or delaying imaging unmasks the pelvis.
D. Increasing the injected FDG dose
A larger dose adds more bladder activity and worsens the problem.

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, Hydration, diuretic and voiding, or delayed images. FDG is excreted in urine and accumulates in the bladder, hiding pelvic disease.

Why is "Stopping the scan and using a gamma camera" not the answer?

A gamma camera cannot perform coincidence PET imaging and does not fix bladder activity.

Why is "Giving oral glucose before imaging" not the answer?

Oral glucose competes with FDG and lowers tumour uptake.

Why is "Increasing the injected FDG dose" not the answer?

A larger dose adds more bladder activity and worsens the problem.

What concept does this question test?

It tests Radiotherapy and nuclear medicine basics: FDG urinary excretion in Radiology. Hydration, a diuretic, voiding before imaging, bladder catheterisation or delayed images reduce this problem.

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 Radiotherapy and nuclear medicine basics: FDG urinary excretion?

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.