['To evaluate the diagnostic significance of CT scan in the localization of the stricture in the upper airway in patients with obstructive sleep apnea syndrome (OSAS).', "Fifty-four patients with OSAS were included in this study. CT scan evaluated the upper airway from the roof of nasopharynx to the glottis using a Phlips Tomoscan AV Expander E1 spiral scanner. The areas and the dimensions of palate, uvula, lingua and epiglottis region, as well as the thickness of retropharyngeal and lateral pharyngeal tissue was evaluated. The reference values had been set-up in 225 normal adult upper airways CT scan, some patients' results were compared with the CT scan results during apnea.", 'There were no any upper airway stricture in 12 patients with OSAS, and there were one or more upper airway stricture sites in other 42 patients. Twenty-four patients had only one stricture site. Fourteen patients had 2 adjacent stricture sites. One patient had three stricture sites. Three patients had 4 upper airway strictures. There was a good concordance between the results of CT scans during awakening and sleeping in 14 patients.'] Do [ Localization of upper airway stricture in patients with obstructive sleep apnea syndrome by CT scan ]?