Optical coherence tomography for the identification and quantification of human airway wall layers

Abstract

Background: Airway remodeling is a key feature in obstructive lung diseases. Near infrared-based optical coherence tomography (OCT) is a novel bronchoscopic imaging technique that generates highly-detailed images of the airway wall. Aim: Identify and quantify human airway wall layers both ex-vivo and in-vivo by OCT and correlate these to histology. Methods: Patients with lung cancer, prior to lobectomy, underwent in-vivo OCT imaging. Ex-vivo OCT imaging was performed in the resected lung lobe after needle insertion for matching with histology. Airway wall layer perimeters were assessed by two independent observers. Airway wall layer areas (total airway wall area, mucosal wall layer area and submucosal wall layer area) were calculated. Results: 13 airways of 5 patients were imaged by OCT. Histology was matched with 51 ex-vivo OCT images and 39 in-vivo OCT images. Significant correlation was found between ex-vivo OCT imaging and histology, in-vivo OCT imaging and histology and ex-vivo and in-vivo OCT imaging for all measurements (Fig 1). Minimal bias was seen in Bland-Altman plots. High inter-observer reproducibility with intra-class correlation coefficients all > 0.90 were detected. Conclusions: OCT is an accurate and reproducible imaging technique for identification and quantification of airway wall layers. Implications: OCT imaging might qualify as the imaging technique of choice to assess airway wall remodeling.