Figure 1c.  (a) Coronal US image of the fetal brain shows complete duplication of normal-appearing cerebral structures. The cerebellar hemispheres are not well visualized, and there appears to be fusion at the posterior fossa. A large cystic structure is seen at the level of fusion (arrow). (b) Transverse US image through the fetal orbits demonstrates the two medial orbits (arrows) separated by a very thin septum of bone. (c) Transverse US image of the fetal face obtained just inferior to b shows two noses (arrows) projecting laterally from a shared medial cheek.