Newborn with ventriculomegaly on prenatal ultrasound

MRI of aqueductal stenosis
Axial (above left) and coronal (above right) T1 MRI without contrast of the brain show dilation of the lateral and third ventricles. Sagittal T2 MRI without contrast of the brain (below) shows narrowing at the aqueduct of Silvius with a decreased amount of CSF within it. The fourth ventricle is normal in size.

The diagnosis was aqueductal stenosis.