Feasibility of Assessing the abnormal Paediatric Airway using Rotational Optical Coherence Tomography – The OCT Air Study

Abnormalities in the paediatric airway are usually diagnosed by a computerized tomography (CT)-scan and diagnostic dynamic bronchoscopies (DDB). However, these methods have several limitations in the airway; CT-scans use a high dose of ionizing radiation, which generally should be avoided in children. Additionally, the CT-output is not dynamic, thus compromising the output due to the impact of the respiratory motion on the airway’s format and volume. Even though DDB output is dynamic, it is visually quantifiable by bronchoscopist, creating a risk of interobserver variability when grading stenoses. This creates a demand for an alternative measuring method that is objectively quantifiable and able to obtain dynamic cross-sectional images of the airway. The catheter-based method Optical Coherence Tomography (OCT) obtains dynamic cross-sectional images by using light close to the infrared range. The method is already implemented within other medical fields. We aim to investigate whether OCT is a feasible method for assessing the diseased paediatric airway. The study is a prospective case series where OCT of the airway was performed on nine paediatric subjects in relation to DDB due to severe respiratory symptoms. The obtained OCT data was subsequently analysed and compared to DDB-output. OCT demonstrated ability to provide a quantitative assessment of airway stenoses with higher accuracy than DDB. Statistical calculations revealed that inspection of the stenotic area during bronchoscopy eestimated lumen area stenosis significantly different in comparison to OCT (15.05 (95% CI: 7.74-22.36) (p<0.001)).