Frontiers in bronchoscopic imaging

Abstract

Bronchoscopy is a minimally invasive method for diagnosis of diseases of the airways and the lung parenchyma. Standard bronchoscopy uses the reflectance/ scattering properties of white light from tissue to examine the macroscopic appearance of airways. It does not exploit the full spectrum of the optical properties of bronchial tissues. Advances in optical imaging such as optical coherence tomography (OCT), confocal endomicroscopy, autofluorescence imaging and laser Raman spectroscopy are at the forefront to allow in vivo high-resolution probing of the microscopic structure, biochemical compositions and even molecular alterations in disease states. OCT can visualize cellular and extracellular structures at and below the tissue surface with near histological resolution, as well as to provide three-dimensional imaging of the airways. Cellular and subcellular imaging can be achieved using confocal endomicroscopy or endocytoscopy.Contrast associated with light absorption by haemoglobin can be used to highlight changes in microvascular structures in the subepithelium using narrow-band imaging. Blood vessels in the peribronchial space can be displayed using Doppler OCT. Biochemical compositions can be analysed with laser Raman spectroscopy, autofluorescence or multispectral imaging. Clinically, autofluorescence and narrow-band imaging have been found to be useful for localization of preneoplastic and neoplastic bronchial lesions. OCT can differentiate carcinoma in situ versus microinvasive cancer. Endoscopic optical imaging is a promising technology that can expand the horizon for studying the pathogenesis and progression of airway diseases such as COPD and asthma, as well as to evaluate the effect of novel therapy.

Comparison of autofluorescence imaging bronchoscopy and white light bronchoscopy for detection of lung cancers and precancerous lesions

“…As a newly developed technology, autofluorescence bronchoscopy shines some light, albeit not strongly, on this problem. It allows rapid scanning of large areas of the bronchial surface for subtle abnormalities that are not visible on WLB 34. However, in comparison with conventional WLB, some autofluorescence bronchoscopy systems have increased sensitivity but significantly reduced specificity 8–13.…”

The role of bronchoscopy in the diagnosis of early lung cancer: a review

“…The results suggested that vessel density was decreased in the smokers as compared to the non-smokers, concluding that smoking would affect not only lung parenchyma but also systemic angiogenesis (32). A B the properties of light waves, with microscopic resolution (1-20 µm) and a penetration depth of maximum 2-3 mm that allows high-definition cross-sectional images of the airway luminal wall (33). Although the OCT system is analogous to that of B-mode ultrasound, the procedure requires no contact between the small optical probe and the tissue and it is able to delineate, in real time, cellular and extracellular structures at a resolution that is 20 times as high as that of ultrasound (34).…”

Advanced Imaging (Positron Emission Tomography and Magnetic Resonance Imaging) and Image-Guided Biopsy in Initial Staging and Monitoring of Therapy of Lung Cancer

“…68 The confocal laser endoscopy system (Cellvizio; Mauna Kea Technologies, Paris, France) uses lasers at specific wavelengths (488 or 660 nm) to excite tissue fluorescence with or without local contrast for microimaging of the respiratory tract (Fig. 5).…”