Magnetic resonance imaging of the upper airway structure of children with obstructive sleep apnea syndrome

The anatomical relationships between lymphoid, bony, and other tissues affe cting the shape of the upper airway in children with obstructive sleep apne a syndrome (OSAS) have not been established. We therefore compared the uppe r airway structure in 18 young children with OSAS (age 4.8 +/- 2.1 yr; 12 m ales and 6 females) and an apnea index of 4.3 +/- 3.9, with 18 matched cont rol subjects (age, 4.9 +/- 2.0 yr; 12 males and 6 females). All subjects un derwent magnetic resonance imaging under sedation. Axial and sagittal T1- a nd T2-weighted sequences were obtained. Images were analyzed with image-pro cessing software to obtain linear, area, and volumetric measurements of the upper airway and the tissues comprising the airway. The volume of the uppe r airway was smaller in subjects with OSAS in comparison with control subje cts (1.5 +/- 0.8 versus 2.5 +/- 1.2 cm(3); p < 0.005) and the adenoid and t onsils were larger (9.9 +/- 3.9 and 9.1 +/- 2.9 cm(3) versus 6.4 +/- 2.3 an d 5.8 +/- 2.2 cm(3); p < 0.005 and p < 0.0005, respectively). Volumes of th e mandible and tongue were similar in both groups; however, the soft palate was larger in subjects with OSAS (3.5 +/- 1.1 versus 2.7 +/- 1.2 cm(3); p < 0.05). We conclude that in children with moderate OSAS, the upper airway is restricted both by the adenoid and tonsils; however, the soft palate is also larger in this group, adding further restriction.