Female, 30 years old, 22 weeks gestational age, with severe fetal ventriculomegaly noted on ultrasound. The lateral ventricles are dilated with measurements at the level of the atria of 18 mm on the right and 17 mm on the left. The third ventricle is mildly prominent. The fourth ventricle is within normal limits. Image quality is not adequate to assess for patency of the cerebral aqueduct.While there may be mild parenchymal thinning in the parieto-occipital regions, the gross morphology of the brain is within normal limits for gestational age. No focal parenchymal signal abnormality is suspected. The cavum septum pellucidum is not clearly visualized, though the corpus callosum is likely present. The brainstem and posterior fossa structures are within normal limits. No evidence to suggest intracranial hemorrhage or any abnormal extra-axial fluid collection is seen. No intracranial masses are appreciated.
Marked dilatation of the lateral ventricles is demonstrated with mild prominence of the third ventricle. The fourth ventricle remains within normal limits. Image quality does not allow for accurate assessment of cerebral aqueduct patency. No additional specific underlying etiology for the ventriculomegaly is identified on this examination.