Female, 38 years old, 23 weeks gestational age, with hydrocephalus detected on fetal ultrasound. Image quality is reduced by fetal motion on most sequences. Within this limitation, the following observations are made.The lateral ventricles are significantly dilated. At the level of the atria, the left lateral ventricle measures up to 23 mm, and the right measures up to 28 mm. The third ventricle is also prominent, but the fourth ventricle is not dilated. The cerebral aqueduct is not discretely visualized. The cerebral hemispheres are thinned by the expanded ventricular system, but otherwise appear to be present in their entirety. The thalami are not fused. The brainstem and cerebellum are unremarkable. The septum pellucidum is absent and may have degenerated secondary to ventriculomegaly. The corpus callosum is not well visualized, and is likely thinned. No evidence to suggest intracranial hemorrhage is seen. A two-vessel umbilical cord is noted. Limited views of the fetal abdomen are otherwise unremarkable.
1.Marked lateral ventriculomegaly is seen. The cerebral aqueduct is not discretely visualized and may therefore be stenosed or underdeveloped. However, motion artifact does compromise the assessment in this regard.2.The cerebral parenchyma is thinned due to ventriculomegaly, though the hemispheres appear to be present in their entirety. The corpus callosum is not well visualized and is likely thinned.3.No additional cerebral or cerebellar anomalies are suspected. 