Upper Airway Motion Depicted at Cine MR Imaging Performed during Sleep: Comparison between Young Patients with and Those without Obstructive Sleep Apnea

To compare the patterns of dynamic airway motion depicted on cine magnetic resonance (MR) images obtained during sleep between young patients with and those without obstructive sleep apnea (OSA).Fast gradient-echo sequences were performed in the sagittal midline by using a 1.5-T unit to create cine MR images. Cine MR images obtained during sleep in 16 young patients with OSA were compared with those obtained in 16 young patients with no airway symptoms of airway disease. The nasopharynx, oropharynx, and hypopharynx were characterized in terms of airway motion as static patent (SP), dynamic patent, intermittent collapsed (IC), or static collapsed (SC); and the maximal diameter and greatest change in diameter (in millimeters) of these airways were calculated. Adenoid tonsil size and mouth position (ie, opened or closed) were determined. Differences in the frequency of MR imaging parameters in the different anatomic regions were evaluated by using Fisher exact, chi 2, and sample t tests.There were statistically significant differences in the following parameters between the two groups: nasopharynx SP (P <.001) and IC (P <.001); hypopharynx SP (P <.001) and IC (P <.001); and mean change in airway diameter of the nasopharynx (P <.001) and hypopharynx (P <.001). The mean adenoid tonsil size in the patients with OSA was larger (P =.006).There are significant differences in the patterns of dynamic airway motion between young patients with and those without OSA.