Computed tomography of choanal atresia: special considerations of the unilateral type.

Seven cases of choanal atresia are presented: four cases with bilateral choanal atresia, and three cases with unilateral choanal atresia. The patients in three of these cases were born with the CHARGE association--an association of choanal atresia with coloboma, heart disease, retarded growth, genital hypoplasia, and ear anomalies. Diagnosis in all cases was confirmed. Computed tomography generally confirms the clinical diagnosis of bilateral choanal atresia. Unilateral choanal atresia, however, presents late, and both the clinical and radiographic manifestations may be subtle. In all our cases of unilateral choanal atresia, computed tomography demonstrated the definitive components accounting for this deformity. Computed tomography, because it so accurately defines the anatomic malformation, is now the imaging modality of choice in this entity.