The magnetic resonance imaging of the upper airway in obstructive sleep apnea syndrome

Objective: We used magnetic resonance imaging(MRI) which could provide super imaging of soft tissue to investigate the difference between the obstructive sleep apnea syndrome(OSAS) and the non snorers. Methods: 23 OSAS patients were diagnosed by whole night polysomnography. Every one or two patients had one age sex matched control subject with no snoring at night. Both 23 OSAS patients and 12 controls took MRI scans of upper airway. Compared those images within nasopharynx, palatopharynx, glossopharynx and hypopharynx. Results: OSAS patients showed smaller airway than controls in almost every aspect, such as sagittal size, horizontal size, the ratio of sagittal size to horizontal size, cross sectional area and volume of the upper airway. The difference in the nasopharynx was an interesting discovery. Conclusion: A structurally abnormal airway might serve as an anatomic substrate for the development of sleep apnea. MRI was a valuable diagnostic tool in the research of OSAS, though it could not be replaced of whole night polysomnography.