Figure 3. Six transverse fast gradient-echo cine MR images (8.2/3.6, 80° flip angle, 8-mm section thickness) obtained in a 5-year-old boy with obstructive sleep apnea, marked obesity, and Bardet Biedl syndrome show the dynamic motion of the hypopharynx to be greater in the left-to-right direction than in the anterior-to-posterior direction. The images were obtained continuously (from top left to bottom right) and demonstrate dynamic change in the size of the airway at the level of the hypopharynx. There is intermittent, nearly complete collapse of the hypopharynx. The change in left-to-right diameter (arrows) is much greater than the change in anterior-to-posterior diameter (arrowheads).