Swept-Source Anatomic Optical Coherence Elastography of Porcine Trachea

Area of Science:

• Medical imaging
• Biomedical engineering
• Pulmonology

Background:

• Quantitative endoscopic imaging is crucial for assessing upper airway obstruction.
• Anatomic optical coherence tomography (aOCT) offers high-resolution, 4D airway lumen geometry.
• Coupling aOCT with pressure measurements enables optical coherence elastography (OCE) for airway wall stiffness characterization.

Purpose of the Study:

• To develop and validate an anatomic optical coherence tomography (aOCT) system for quantitative assessment of airway geometry and wall stiffness.
• To evaluate the system's capability in measuring airway compliance using optical coherence elastography (OCE).
• To assess the potential of the aOCT system for future clinical applications in diagnosing upper airway obstruction.

Main Methods:

• A novel aOCT system was developed using a wavelength-swept laser source and a 0.82 mm fiber-optic catheter.
• The system was deployed via a commercial flexible bronchoscope, performing helical scans for airway geometry and cross-sectional area (CSA) measurements.
• Preliminary validation involved measuring compliance of a latex rubber tube and ex vivo porcine trachea by correlating aOCT-derived CSA with applied pressure.

Main Results:

• The aOCT system successfully measured airway geometry and quantified cross-sectional area (CSA).
• Experiments on a latex tube yielded a compliance of 0.68±0.02 mm²/cmH₂O (R²=0.98).
• Ex vivo porcine trachea showed measured compliance ranging from 1.06±0.12 to 3.34±0.44 mm²/cmH₂O (R²>0.81), consistent with human airway measurements.

Conclusions:

• The developed aOCT system, coupled with OCE, can accurately assess airway wall compliance.
• The system's ability to measure airway geometry and stiffness shows potential for improving surgical decision-making in cases of upper airway obstruction.
• This technology holds promise for future in vivo human studies to evaluate airway conditions non-invasively.