Airway wall thickness assessed using computed tomography and optical coherence tomography.

Area of Science:

• Pulmonary Medicine
• Medical Imaging
• Respiratory Physiology

Background:

• Computed tomography (CT) reliably quantifies medium to large airway dimensions.
• Optical coherence tomography (OCT) offers micron-scale resolution for imaging small airways (≤2 mm diameter).

Purpose of the Study:

• To correlate airway dimension measurements obtained via OCT with those from CT scans.
• To assess the relationship between OCT and CT measurements and lung function (spirometry).

Main Methods:

• Forty-four current and former smokers underwent spirometry, CT scans, and OCT imaging during bronchoscopy.
• Specific bronchial segments were identified and measured using OCT and 3D CT reconstructions.

Main Results:

• Strong correlations were found between CT and OCT for lumen and wall area (r=0.84, r=0.89).
• OCT measurements for lumen and wall area were lower than CT (31% and 66%, respectively).
• OCT demonstrated greater sensitivity than CT in detecting airway wall changes impacting FEV1.

Conclusions:

• OCT is a viable method for measuring airway wall dimensions.
• OCT may be more sensitive than CT in identifying small airway alterations linked to FEV1 changes in obstructive lung disease.