History: 15-year-old girl with a history of right maxillary sinusitis and right nasal obstruction
Choanal atresia is a congenital disorder where the back of the nasal passage (choana) is blocked, usually by abnormal bony or soft tissue (membranous) due to failed recanalization of the nasal fossae during fetal development.
Findings: An axial image through the lower nasal cavity demonstrates an air-fluid level within the right nasal cavity, which is occluded posteriorly by a thin, bony plate. Also present is mucoperiosteal thickening within the right maxillary sinus.
Diagnosis: Unilateral choanal atresia
Discussion: Choanal atresia is an unusual congenital deformity in which there is obstruction of the posterior nasal cavity. There may be complete obstruction by either a bony (85%) or membranous (15%) plate or a partial obstruction from a posterior nasal cavity stenosis. Because infants are obligate nose breathers, babies with bilateral atresia will present shortly after birth with respiratory distress. Unilateral lesions often present later in childhood or even early adulthood.; 50% of the cases are isolated, and the remaining are associated with other congenital anomalies. CT is the radiographic modality of choice in evaluating these patients. Axial images should be angles +15 degrees to the hard plate for optimal visualization of this anomaly. The treatment is surgical.
Aunt Minnie’s Pearls
- Bony or membranous obstruction of the posterior nasal cavity = choanal atresia.
- Babies with bilateral atresia will present with respiratory distress at birth.