Vein of Galen Malformation

Etiology:
— Failure of Vein of Galen and straight sinus development
— Is not an aneurysm and does not involve Vein of Galen
Imaging CXR:
— In neonates extracardiac left to right shunt leads to acyanosis and increased pulmonary blood flow
Imaging MRA:
— Choroidal type: Multiple fistulae from posterior choroidal artery and adjacent midbrain thalamoperforating arteries to median prosencephalic vein (of Markowski) = pial arteriovenous malformation with deep venous drainage
— Mural type: Single fistula in wall of median prosencephalic vein (of Markowski) = direct arteriovenous fistula
DDX:
Complications:
Treatment: Emoblization
Clinical: Presentation varies with age – choroidal type presents in neonates with high output CHF, mural type presents in children with hydrocephalus and in adults with subarachnoid hemorrhage

Radiology Cases of Vein of Galen Malformation

US of Vein of Galen malformation — Coronal and sagittal US of the brain shows a high flow vascular structure in the region of the median prosencephalic vein. A bruit was subsequently noted in this area.

US of vein of Galen malformation — Coronal grayscale US of the head (above left) shows a large round hypoechoic structure in the midline between the posterior horns of the lateral ventricles and above the cerebellum on the sagittal grayscale US (above right) which on color doppler (below) has turbulent blood flow within it.

CT and angiogram of Vein of Galen malformation — Axial CT without contrast of the brain (left) shows a marked amount of hydrocephalus, diffuse intracranial calcifications, and no intracranial hemorrhage. A tubular structure is noted in the midline posteriorly between the occipital horns of the lateral ventricles. Lateral image from a cerebral angiogram (right) arterial injection shows enlarged posterior choroidal and lenticulostriate arteries feeding an arteriovenous malformation which drains into enlarged transverse sinuses bilaterally.