Assessment of the airway in obstructive sleep apnea syndrome with 3-dimensional airway computed tomography

OBJECTIVE: The goal was to evaluate 3-dimensional airway CT for upper airway assessment in obstructive sleep apnea syndrome (OSAS). DESIGN: Airway CT was obtained and 3-dimensional airway models were constructed prospectively for 40 patients with OSAS and 10 controls. Airway dimensions were correlated with polysomnography, and comparison was made between patients with and without OSAS. RESULTS: OSAS patients had a mean respiratory distress index of 51.9 events per hour. The mean minimum cross-sectional area (XSA) in the neutral position was 67.1 mm². Minimum XSA decreased in both the inspiratory and expiratory phases to 16.3 mm² and 15.0 mm², respectively (P < 0.001). Complete airway obstruction occurred in 1 or more phases of respiration in 28 patients. Neither airway XSA nor length of obstruction correlated with sleep apnea parameters. No statistically significant differences in airway dimensions were found between OSAS and control patients. CONCLUSIONS: Airway CT demonstrates dynamic airway obstruction in OSAS but does not correlate well with clinically important disease parameters.