Question:hard
This MRI of the skull represents:
This MRI of the skull represents:
Show Hint
A dilated midline vein in the quadrigeminal cistern behind the splenium.
Updated On: Jun 24, 2026
- Vein of Galen
- Dandy-Walker syndrome
- Pneumocephalus
- Crouzon syndrome
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: Focus on the location and shape on the MRI - a prominent midline venous channel sitting under the cerebral hemispheres in the quadrigeminal cistern, behind the splenium. This anatomical signature identifies the great cerebral vein.
Step 2: The vein of Galen forms from the joining of the two internal cerebral veins and the basal veins of Rosenthal, then sweeps backward and upward to empty into the confluence of the inferior sagittal and straight sinuses. When dilated as a malformation, it produces exactly this enlarged central venous structure.
Step 3: Cross off the alternatives by their imaging look. Dandy-Walker gives a large posterior-fossa cyst continuous with the fourth ventricle plus vermis hypoplasia, pneumocephalus shows air signal, and Crouzon is a bony craniosynostotic deformity. The dilated midline vein fits only the vein of Galen.
\[\boxed{\text{Vein of Galen}}\]
Step 2: The vein of Galen forms from the joining of the two internal cerebral veins and the basal veins of Rosenthal, then sweeps backward and upward to empty into the confluence of the inferior sagittal and straight sinuses. When dilated as a malformation, it produces exactly this enlarged central venous structure.
Step 3: Cross off the alternatives by their imaging look. Dandy-Walker gives a large posterior-fossa cyst continuous with the fourth ventricle plus vermis hypoplasia, pneumocephalus shows air signal, and Crouzon is a bony craniosynostotic deformity. The dilated midline vein fits only the vein of Galen.
\[\boxed{\text{Vein of Galen}}\]
Was this answer helpful?
0
