Clinical History: A 6-month-old male child with right choanal atresia. Pre-surgical evaluation. Non-enhanced axial CT scan of paranasal sinuses.

Axial images show narrowing of right posterior choana

Findings: There is a severe bony narrowing seen involving the right choana with retained secretions in the right nasal cavity. The left choana is widely patent. Mucosal thickening is seen in both ethmoid and maxillary sinuses with opacification of both mastoid air cells. Both orbits are within normal limits. Visualized bones are unremarkable.