MR diagnosis of vein of Galen aneurysmal malformations using virtual cisternoscopy.

Vein of Galen aneurysmal malformations (VGAMs) are rarely seen intracranial congenital vascular malformations with extremely complex vascular architectures. We present two newborns with an unclear intracranial mass being discovered in routine intrauterine ultrasonography. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) identified these lesions as VGAMs. Besides conventional MRA analysis, "virtual cisternoscopy"-a special kind of virtual endoscopy combining perspective volume rendering and motion-was applied to assess the intracranial vasculature. One newborn was treated by means of interventional neuroradiology with coiling of the median prosencephalic vein. The clinical outcome in this case was excellent. The other will undergo interventional therapy shortly.