This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
Preferred imaging modality for choanal atresia is 
Select and explain. 
A. X ray, B. CT SCAN, C. MRI, D. PET SCAN
B: CT SCAN
Answer: B: CT SCAN 
Explanation: CT SCAN in choanal atresia CT SCAN in coronal and saggital projections provides a thorough evaluation of choanal atresia and adjescent structures. The axial views supply fundamental information including site of obstruction, composition of atretic plate and unilateral or bilateral involvement. Thus CT SCAN is the preferred imaging modality.