Brainstem–vermis and brainstem–tentorium angles allow accurate categorization of fetal upward rotation of cerebellar vermis

Abstract

The BV angle and, to a lesser degree, the BT angle are simple and reproducible measurements that provide valuable additional information for the categorization of upward rotation of the fetal cerebellar vermis. From mid gestation, a BV angle > 45° is strongly suggestive of a Dandy-Walker malformation, while a measurement < 30° favors the diagnosis of a Blake's pouch cyst.