Bronchoscopic Journey of in vivo Real-Time Microscopic Imaging in ILD: A Case Series

Patients with interstitial lung diseases (ILDs) frequently present with nondiagnostic high-resolution CT (HRCT) scan and bronchoalveolar lavage (BAL) results, resulting in the need for invasive surgical or cryo-lung biopsy that is associated with significant morbidity. Confocal laser endomicroscopy (CLE) and optical coherence tomography (OCT) are high-resolution laser and light-based techniques that provide real-time imaging of the alveolar compartment during bronchoscopy with a different depth and field of view.

The aim of the study was to correlate OCT and CLE imaging to HRCT imaging in ILD.

This is a retrospective case series of 20 ILD patients who underwent alveolar CLE and OCT imaging during a standard bronchoscopy with BAL, followed by a lung biopsy when indicated. CLE and OCT imaging were compared to four main HRCT patterns and histology. The final diagnosis was based on the multidisciplinary discussion diagnosis.

Bronchoscopic CLE and OCT imaging were feasible and safe and provided additional high-detailed anatomical information compared to the HRCT. Bronchoscopic real-time CLE was capable of identification of "alveolar cells" (ground glass opacities) and lung fibrosis (increased alveolar elastin fibers). Bronchoscopic real-time OCT allowed for visualization of "patchy fibrotic disease", "honeycombing" (microcysts), and mucosal granulomas in the airways.

Bronchoscopic CLE and OCT of the alveolar compartment is feasible and safe and enables minimally invasive, high-resolution detection of specific ILD features with the potential to improve ILD diagnostics and monitoring and decrease the need for surgical or cryo-lung biopsies.