Scientists have developed a faster method for measuring the elasticity of airway walls, a property that can reveal important information about respiratory health. The technique, reported in the Journal of Biomedical Optics , could help assess conditions such as airway obstruction or burn injury during a standard bronchoscopy exam, without adding significant time or risk to the procedure.
Airway wall elastography, performed with endoscopic optical coherence tomography (OCT), can detect subtle changes in how airway tissue deforms with breathing. By combining OCT's high-resolution imaging with a pressure sensor, clinicians can calculate cross-sectional compliance—how much the airway expands or contracts under pressure. However, current methods require relatively long scan times, which can be impractical in clinical settings.
The new approach uses a "retrospective, respiratory-gated" 4D OCT scanning method. Instead of imaging the airway in sequence from one end to the other, the researchers move the scanning catheter in a sawtooth pattern along a 50 mm section. This motion allows each location to be captured at different points in the breathing cycle, both high and low pressure. Afterward, the data are sorted by position and phase of respiration to calculate compliance at each point, with a spatial resolution of 0.5 mm.
The team validated the method first in simulations, then in rigid and flexible models, and finally in live pigs. In a rigid 3D-printed model, the system reproduced the geometry to within 0.11 mm of the true dimensions. In a uniform silicone tube, compliance measurements varied by only about 4 percent, demonstrating high repeatability. Tests on a structured balloon successfully mapped areas of high and low elasticity. Finally, in live pigs, the system measured compliance values consistent with earlier studies, while capturing clinically relevant variations along the airway.
Importantly, the entire 50 mm scan took less than 42 seconds—about 0.42 seconds per measurement—making it feasible for routine use during bronchoscopy. The authors suggest it could be valuable for diagnosing and monitoring upper airway disorders, assessing injury, and potentially guiding treatment decisions.
For details, see the original Gold Open Access article by S. J. Soundararajan et al., " Method for retrospective, respiratory-gated, anatomical optical coherence tomography for airway wall elastography ," J. Biomed. Opt. 30(12) 124502 (2025) doi: 10.1117/1.JBO.30.12.124502 .
