Evaluation of the pharyngeal airway in obstructive sleep apnea: study by ultrafast MR imaging.

To evaluate dynamic morphologic changes of the respiratory tract in patients with obstructive sleep apnea syndrome (OSAS), the cross section and the midline sagittal section of the upper respiratory tract of OSAS were examined using ultrafast MR imaging technique. In 10 men and 2 women diagnosed with OSAS, 30 images obtained in 30-90 s at each location of sagittal and multilevel transverse sections were observed with cineloop display in awake and sleeping status. No patients had complete pharyngeal obstruction while awake. On the other hand, 9 patients had at least one occluded site, and 3 patients had wider obstructed sites during sleep. We are convinced that ultrafast MR imaging is very useful in determining the indication and the method for surgical treatment for OSAS.