Choanal atresia is an uncommon developmental defect characterized by lack of communication between the nasal cavity and the nasopharynx. This plate may be bony (70-90%), membranous (10%), or both. The atresia may involve one or both nasal cavities, and other congenital anomalies may be associated with it. If bilateral choanal atresia is present at birth, it requires immediate diagnosis and intervention to permit respiration. Unilateral choanal atresia is usually diagnosed at a later stage.

CT in the axial plane was extremely valuable in demonstrating choanal atresia. The configuration of the nasal cavity is displayed in its entire length and it is possible to visualize stenosis and septal deviation and to differentiate between the bony and membranous components.

Other congenital anomalies such as craniofacial cleft palate, Treacher Collins syndrome, and cardiovascular and abdominal malformations have been reported in 20%-50% of cases of choanal atresia