  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.
