Prenatal diagnosis of an aneurysm of the vein of Galen with three-dimensional color power angiography.

The prenatal diagnosis of an aneurysm of the vein of Galen has been reported on only a few occasions. This rare arterio-venous fistula is suspected when an intracerebral hypoechoic cyst is found in which blood flow can be demonstrated by Doppler ultrasound. This is one of the few conditions where Doppler ultrasound is critical for the diagnosis. Three-dimensional color power Doppler (3D-CPA) is a recent ultrasound modality which enables the three-dimensional visualization of vessels and which is more readily available than magnetic resonance imaging (MRI) We report a fetus in which an aneurysm of the vein of Galen was detected at 33 weeks' gestation and where the application of 3D-CPA enabled a better understanding of the spatial orientation and course of the dilated vessels. The neonate was successfully treated with coil angiography but subsequently died at 5 months of age from cardiac decompensation. Where fetal malformations involve the vascular system, 3D-CPA appears to be a promising technique.