Severe hydrocephalus

1-Water bag skull.

2-Mid line structures including falx are present.

3-Look to the periphery, there is still brain tissue seen.

Moderate to severe hydrocephalus secondary to aqueductal stenosis. A transaxial US scan of a fetus at 30 weeks gestation demonstrates an enlarged fetal head with thinned but present temporoparietal cortical mantle (arrows) along the posterolateral aspect of the calvaria. The third ventricle (∗) is also dilated between the thalami. Although the temporoparietal cortical mantle is also present anteriorly, it cannot be appreciated because of reverberation artifacts.