Ultrasound of the Fetal Veins Part 3: The Fetal Intracerebral Venous System.

The study of the intracerebral venous system in the fetus can only be achieved by means of high-resolution ultrasound equipment with sensitive color Doppler. In the past two decades, there has been a growing interest in the ultrasound examination of the fetal brain with few studies reporting on the brain vasculature during various stages of gestation. In comparison to other fetal venous systems, reports on the assessment of the fetal cerebral venous system are still scarce. This article presents a review on the fetal intracranial venous system with detailed discussions on the anatomy of the superficial and deep cerebral veins. Color Doppler of the main fetal cerebral veins to include the superior sagittal sinus, the straight sinus, the vein of Galen, the internal cerebral veins, the transverse sinuses and others is also discussed. Furthermore, this article highlights abnormal clinical conditions such as aneurysm of the vein of Galen, thrombosis of the dural sinus and variation in the course of some veins such as the straight sinus and falcine sinus. The role of pulsed Doppler examination in normal and growth-restricted fetuses is also discussed.