Figure 1.

(A) Experimental setup using 25-keV X-rays at beamline BL20XU at the SPring-8 synchrotron in Japan, using the setup described in Reference 10, with a gold absorption grid of 25.4-μm period (Gilder grids, G1000HS-G3), and distances of 0.1 m grid-to-sample and 1 m sample-to-detector. The lens-coupled charge-coupled device detector captures a 721 × 497-μm field of view with 0.18-μm pixels using a 100-ms exposure. Airway images are reconstructed using a correlation-based analysis detailed in References 6–8. (B) Single-grid–based phase–contrast X-ray imaging (SGB-PCXI) differential contrast image of the in vivo trachea surface. Scale bar = 100 μm. (C) Airway surface liquid (ASL) depth measurements, where each data point represents a measurement, and the darker bars indicate the mean (±SD) of measurements at that time point. Hypertonic saline (HS)–P308 was delivered after the t = 0 time point, analyzed by one-way repeated-measures (RM)-ANOVA to detect differences compared to baseline (t = 0). Statistical significance was set at a P value of 0.05 and a power of 0.8 for all analyses. (D) Changes in the cartilage-to-surface distance over time, analyzed by two-way RM-ANOVA with Bonferroni multiple comparisons to detect significant differences between treatments at matching time points. In the 5-minute break between sequences, researchers entered the imaging hutch to change the treatment solution.