Neuroimaging: pituitary microadenoma: 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 · Neuroimaging: pituitary microadenoma

Sample item

In a patient with suspected Cushing disease, how does a small pituitary microadenoma typically appear on early dynamic contrast MRI?

AIsointense to the gland on every phaseBHyperenhancing relative to the normal glandCCalcified with a rim of enhancementDHypoenhancing relative to the avidly enhancing normal gland

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

The answer and the reasoning

D. Hypoenhancing relative to the avidly enhancing normal gland

The normal pituitary has no blood-brain barrier and enhances rapidly, while microadenomas enhance more slowly, so they look relatively dark on early dynamic images. Dynamic imaging therefore improves detection of lesions invisible on routine post-contrast scans. Inferior petrosal sinus sampling may be needed when MRI is negative.

Option by option

A. Isointense to the gland on every phase
Isointensity on all phases would make the adenoma undetectable.
B. Hyperenhancing relative to the normal gland
A microadenoma does not enhance faster than the normal gland.
C. Calcified with a rim of enhancement
Calcified lesions suggest craniopharyngioma, not a microadenoma.
D. Hypoenhancing relative to the avidly enhancing normal gland (correct)
Correct. The adenoma enhances later than the normal gland.

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 D, Hypoenhancing relative to the avidly enhancing normal gland. The normal pituitary has no blood-brain barrier and enhances rapidly, while microadenomas enhance more slowly, so they look relatively dark on early dynamic images.

Why is "Isointense to the gland on every phase" not the answer?

Isointensity on all phases would make the adenoma undetectable.

Why is "Hyperenhancing relative to the normal gland" not the answer?

A microadenoma does not enhance faster than the normal gland.

Why is "Calcified with a rim of enhancement" not the answer?

Calcified lesions suggest craniopharyngioma, not a microadenoma.

What concept does this question test?

It tests Neuroimaging: pituitary microadenoma in Radiology. Dynamic imaging therefore improves detection of lesions invisible on routine post-contrast scans. Inferior petrosal sinus sampling may be needed when MRI is negative.

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 Neuroimaging: pituitary microadenoma?

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.