Innovative Optical Method Enhances Airway Wall Elasticity Mapping During Bronchoscopy

Researchers have introduced a revolutionary technique for assessing the elasticity of airway walls, a key indicator of respiratory health. This advancement, detailed in the Journal of Biomedical Optics, promises to improve the evaluation of respiratory conditions such as airway obstruction and burn injuries during standard bronchoscopy procedures, all while minimizing time and risk.

The newly developed method, known as airway wall elastography, utilizes endoscopic optical coherence tomography (OCT) to monitor subtle changes in airway tissue deformation as a patient breathes. By integrating OCT's high-resolution imaging capabilities with a pressure sensor, healthcare professionals can measure cross-sectional compliance, which refers to the airway's ability to expand or contract under varying pressures. Traditional methods, however, often require lengthy scanning periods, making them impractical for clinical environments.

To address this limitation, researchers have implemented a 'retrospective, respiratory-gated' 4D OCT scanning approach. Rather than sequentially imaging the airway from one end to the other, the scanning catheter is moved in a sawtooth pattern across a 50 mm segment. This innovative movement captures each location at different phases of the respiratory cycle, accommodating both high and low pressure. The collected data is subsequently organized by position and respiratory phase, allowing for precise compliance calculations at each site with a spatial resolution of 0.5 mm.

The methodology underwent thorough validation, starting with simulations and progressing to tests on rigid and flexible models, before being applied to live pigs. In a rigid 3D-printed model, the system accurately replicated the geometry to within 0.11 mm of the actual dimensions. Compliance measurements from a uniform silicone tube showed only a 4% variance, indicating high consistency in results. Furthermore, tests on a structured balloon successfully identified areas exhibiting varying levels of elasticity. In live pigs, the technique yielded compliance values that aligned with prior studies and captured clinically significant variations throughout the airway.

Significantly, the entire 50 mm scan is completed in less than 42 seconds, averaging about 0.42 seconds per measurement, which makes it feasible for routine use during bronchoscopic examinations. The authors of the study suggest that this technique could be instrumental in diagnosing and monitoring upper airway disorders, assessing injuries, and possibly informing treatment decisions.

For further details, refer to the original study: Srikamal J. Soundararajan et al, 'Method for retrospective, respiratory-gated, anatomical optical coherence tomography for airway wall elastography,' Journal of Biomedical Optics (2025). DOI: 10.1117/1.JBO.30.12.124502.