Abstract:

Objective  To investigate the correlation of soft tissue structure of upper airway with the pathogenesis of obstructive sleep apnea syndrome (OSAS) in adolescents age group by analyzing magnetic resonance imaging (MRI) of upper airway.Methods  The subjects were divided into obese OSAS, obese controls and normal weight controls groups according to the results from polysomnography and body mass index measurements; Upper airway was scanned by MRI sagittally and axially; upper airway at all levels and soft tissue was analyzed by Amira Medical image analysis system.Results Tongue volumes in obese OSAS and obese controls were significantly greater than that in normal weight controls (P<0.05); tonsil and adenoid volumes in obese OSAS were significantly higher than those in two control groups (P<0.05 or P<0.001), but no significant difference was found between two control groups.The volumes of lateral pharyngeal wall in obese OSAS were higher than those in obese controls and normal weight controls (P<0.05 or P<0.001), and they were higher in obese controls compared with normal weight controls (P<0.05).In obese OSAS group, positive correlations were found between volumes of lateral pharyngeal wall and apnea/hypopnea index (AHI) (r = 0.879,P<0.01), as well as volumes of tonsils and AHI (r = 0.824, P<0.01).Conclusion  Obesity can increase the soft tissue volumes around upper airway, thereby increase the upper airway obstruction; lateral pharyngeal wall and adenoid volumes play major roles in evaluating the severity of OSAS in adolescents.
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Key words: adolescents, obesity;obstructive sleep apnea syndrome, magnetic resonance spectroscopy