Choanal atresia: precise CT evaluation.

Computed tomography facilitates the diagnosis of children with choanal atresia. This modality defines the full anatomic abnormality of bony choanal atresia: medial bowing and thickening of the lateral wall of the nasal cavity, enlargement of the vomer, and fusion of these elements. Bony atresia patients can be clearly separated from those with membranous choanal atresia. In membranous atresia, the lateral wall of the nasal cavity is minimally affected and the vomer is normal. This precise anatomic evaluation aids in determining the surgical approach.