Asymmetric ventriculomegaly, interhemispheric cyst and dysgenesis of the corpus callosum (AVID)

Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum (AVID) is a triad of congenital cerebral anomalies.

Radiographic features

• markedly asymmetric enlargement of the lateral ventricles may be the initial finding on routine fetal morphology ultrasound.
• interhemispheric cyst 
• dysgenesis of the corpus callosum
• absent cavum septum pellucidum
• macrocephaly

Associations

Other congenital abnormalities may be present, including Dandy-Walker malformation, grey matter heterotopia or polymicrogyria.

Treatment and prognosis

Variable but generally severe neurologic and developmental delay.