Neuroimaging: Dandy-Walker malformation: 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 · Neuroimaging: Dandy-Walker malformation

Sample item

A child with macrocephaly has MRI showing vermian hypoplasia, a cystic dilated fourth ventricle that communicates with the posterior fossa cyst, and an elevated tentorium. What is the diagnosis?

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

The answer and the reasoning

D. Dandy-Walker malformation

Dandy-Walker malformation includes hypoplasia or absence of the vermis, cystic dilatation of the fourth ventricle and an enlarged posterior fossa with elevated torcula. Hydrocephalus is common. Joubert syndrome shows the molar tooth sign at the midbrain.

Option by option

  • A. Chiari II malformation

    Chiari II has a small posterior fossa.

  • B. Medulloblastoma

    Medulloblastoma is a solid enhancing mass.

  • C. Joubert syndrome

    Joubert syndrome shows the molar tooth sign.

  • D. Dandy-Walker malformation (correct)

    Correct. Vermian hypoplasia with a posterior fossa cyst and high torcula is Dandy-Walker.

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.

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Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is D, Dandy-Walker malformation. Dandy-Walker malformation includes hypoplasia or absence of the vermis, cystic dilatation of the fourth ventricle and an enlarged posterior fossa with elevated torcula.

Why is "Chiari II malformation" not the answer?

Chiari II has a small posterior fossa.

Why is "Medulloblastoma" not the answer?

Medulloblastoma is a solid enhancing mass.

Why is "Joubert syndrome" not the answer?

Joubert syndrome shows the molar tooth sign.

What concept does this question test?

It tests Neuroimaging: Dandy-Walker malformation in Radiology. Hydrocephalus is common. Joubert syndrome shows the molar tooth sign at the midbrain.

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: Dandy-Walker malformation?

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.