Banana and lemon sign is seen in :
The typical ultrasound cranial signs in open spina bifida are 'lemon sign 'and 'banana sign'.Lemon sign is due to scalloping of the frontal bones. Banana sign is the abnormal anterior curvature of the cerebellum. Refer page no 487 of Text book of obstetrics,sheila balakrishnan,2 nd edition.
Neural tube defect
Hydrops fetalis
Twins
lUD
Diagnosis in obstetrics