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.

Thrombosed dural sinus malformation in a fetus: a case report.

BACKGROUND AND PURPOSE: A thrombosed dural sinus malformation (DSM) is a rare condition, the clinical features of which have not yet been completely characterized. Here, we describe the clinical course of a patient with a thrombosed DSM and discuss the outcomes in live birth cases from a review of the literature. CASE DESCRIPTION: An ultrasonography examination of a 32-year-old woman at 25 weeks' gestation indicated a fetal posterior fossa mass. The size of the intracranial mass remained constant during the second trimester and was observed to decrease from 33 weeks of gestation. A postnatal diagnosis of thrombosis in the dural sinus was established by magnetic resonance imaging and venography. No brain damage or hydrocephalus was noted. Although the circumference of the infant's head was enlarged at birth, her neurological outcome was normal at 1 year of age. CONCLUSIONS: Although normal cranial circumference is reportedly an essential factor for a favorable prognosis, the patient in this report with a cranial circumference at + 2.0 SD (35.6 cm) had a favorable prognosis. Further studies focused on improving clinical diagnostic accuracy in this rare entity will facilitate appropriate counseling.

Prenatal diagnosis of torcular herophili thrombosis: report of 2 cases and review of the literature.

Prenatally diagnosed thrombosis of the torcular herophili is very rare, and it is sometimes misdisgnosed due to unfamiliarity. Sonography with color Doppler imaging is the key imaging modality for prenatal diagnosis of torcular herophili thrombosis. Typical prenatal sonographic findings include a well-defined triangular anechoic collection in the occipital region and an echogenic structure within the collection, which represents the thrombus. Fetal magnetic resonance imaging is usually used as an adjunctive modality for prenatal diagnosis, as it confirms the diagnosis by providing more precise anatomic information and better characterization of the lesion. We present 2 cases of thrombosis of an ectatic torcular herophili with serial sonographic and magnetic resonance imaging examinations, as well as a review of the literature regarding the prenatal diagnosis of torcular herophili thrombosis.