In vivo endoscopic autofluorescence microspectro-imaging of bronchi and alveoli

TL;DR

This paper introduces a novel endoscopic autofluorescence microspectro-imaging technique using fibered confocal fluorescence microscopy to analyze bronchial and alveolar tissue microstructure in vivo during bronchoscopy.

Contribution

The study develops a flexible, spectroscopic fibered confocal microscopy system capable of real-time imaging and spectral analysis of lung tissues during bronchoscopy.

Findings

Imaging of elastin in bronchial and alveolar tissues in vivo.

Detection of autofluorescence from alveolar macrophages in smokers.

Potential for in vivo exploration of lung extracellular matrix.

Abstract

Fibered confocal fluorescence microscopy (FCFM) is a new technique that can be used during a bronchoscopy to analyze the nature of the human bronchial and alveolar mucosa fluorescence microstructure. An endoscopic fibered confocal fluorescence microscopy system with spectroscopic analysis capability was developed allowing real-time, simultaneous images and emission spectra acquisition at 488 nm excitation using a flexible miniprobe that could be introduced into small airways. This flexible 1.4 mm miniprobe can be introduced into the working channel of a flexible endoscope and gently advanced through the bronchial tree to the alveoli. FCFM in conjunction with bronchoscopy is able to image the in vivo autofluorescence structure of the bronchial mucosae but also the alveolar respiratory network outside of the usual field of view. Microscopic and spectral analysis showed that the signal mainly originates from the elastin component of the bronchial subepithelial layer. In non smokers, the system images the elastin backbone of the aveoli. In active smokers, a strong autofluorescence signal appears from alveolar macrophages. The FCFM technique appears promising for in vivo exploration of the bronchial and alveolar extracellular matrix.