Which sonographic sign describes the choroid plexus as dangling in the setting of ventriculomegaly?

• A. Dangling choroid plexus
• B. Choroid plexus cyst
• C. Periventricular leukomalacia
• D. Corpus callosum agenesis

Answer: (A)

The sign being described occurs when the lateral ventricle is greatly dilated, so the choroid plexus, which normally lines the ventricle, becomes stretched and appears to hang into the ventricle. This dangling appearance is a recognizable sonographic sign of ventriculomegaly and hydrocephalus.

A choroid plexus cyst would look like a discrete round cyst within the choroid plexus itself, not a strand hanging into the ventricle. Periventricular leukomalacia shows white-matter injury around the ventricles with echogenicities or cystic changes rather than a dangling choroid plexus. Corpus callosum agenesis involves midline brain structures and has different associated findings; the dangling choroid plexus sign is specifically described for marked ventriculomegaly.