Skull shape abnormal with flattening of frontal bones : "lemon"-shaped skull = lemon sign
Ventriculomegaly
Elongated and curved cerebellum, due to ptosis through foramen magnum : "banana"-shaped cerebellum = banana sign
Spine anomaly with spina bifida aperta, dural sac is exposed to amniotic fluid, no CSF nor cord outpouching : myeloschisis.
Lemon, banana + spina bifida = Chiari II malformation.
Abnormal angle at lumbo-sacral junction with excessive flexion of the spine.
Unilateral clubfoot, as a consequence of spina bifida.
Ruling out underlying Meckel-Gruber syndrome : absence of postaxial polydactyly, absence of cystic or hyperechoic kidneys.