This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis in obstetrics, Subject name: Gynaecology & Obstetrics
Banana and lemon sign is seen in : 
Select and explain. 
A. Neural tube defect, B. Hydrops fetalis, C. Twins, D. lUD
A: Neural tube defect
Answer: A: Neural tube defect 
Explanation: 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.