Banana and lemon sign is seen in which fetal anomalies:
Neural tube defect
Hydrops fetalis
Twins
IUD
Signs of Spina bifida on Ultrasound

Small biparietal diameter.
Ventriculomegaly.
Frontal bone scalloping or the so called lemon sign.
Elongation and downward displacement of the cerebellum-the so called banana sign.
Effacement or obliteration of the cisterna megna.