Fig 2. Example of MRI data acquired from each of the three subjects.

Top row: Sagittal ¹H MRI of the head and neck anatomy including the upper airway, captured to create the virtual airway surface for CFD simulations. Middle row: Sagittal magnitude (“Mag”) MR images of inhaled ¹²⁹Xe in the upper airway at a selected dynamic time (note: slices do not perfectly correspond to ¹H MRI slices above). Bottom row: Foot-Head velocity (v_FH) maps corresponding to the magnitude images above (one dynamic image), reconstructed from ¹²⁹Xe gas PC MRI data. Red velocities represent flow in the foot to head direction, blue represents flow in the head to foot direction.