Figure 2.

Three-dimensional ultrashort echo-time MRI with chest and airway coverage in four neonatal patients (resolution, 0.7 × 0.7 × 0.7 mm). Coronal, sagittal, and axial planes of ungated images acquired during tidal breathing are shown in the three left columns. Insets (yellow): respiratory-gated images reconstructed from the same imaging data show axial views of tracheal dynamics at end-expiration (green) and end-inspiration (magenta). Endoscopic results in these four patients indicated absence of TM in Subjects A and B and presence of TM in Subjects C and D, which qualitatively agrees with the degree of dynamic tracheal collapse observed on the respiratory-gated images at right. TM = tracheomalacia.