Feature Of The Week 7/15/12: 3D Simultaneous Optical Coherence Tomography and Confocal Fluorescence Microscopy for Investigation of Lung Tissue
The acute respiratory distress syndrome (ARDS) is a life-threatening condition of the lung leading to a state of decreased lung compliance and blood oxygenation efficiency. The treatment of patients utilizes artificial ventilation, which has a tremendous impact on the lung’s sensitive microenvironment and can even lead to further damage in the form of ventilator induced lung injury (VILI). As a basis for the understanding of physiological processes occurring on the microscale of lung tissue, the alveolar tissue, contact free imaging can elucidate dynamic changes during artificial ventilation. The main interest focuses here on the rearrangement of alveolar geometry and the change of elastic fiber distributions, lengths and densities.
To this end, we combined Fourier domain optical coherence tomography (FD-OCT) with confocal fluorescence microscopy (CFM), where geometrical features of the lung tissue are acquired using OCT and specific imaging of elastic fibers is obtainable via CFM utilizing exogenous fluorescence staining for elastin. Both modalities have the ability to perform contact-free, three-dimensional, high-resolution imaging, suitable for the investigation of the micrometer sized alveolar tissue and its elastic components. Utilizing different numerical apertures for the distinct modalities, the lateral resolution of CFM could be enhanced by a factor of 6.5 with respect to the OCT resolution. Consequently, tiny fibers of micrometer thickness are now identifiable via CFM in addition to the overall geometrical structure revealed by OCT. Using this combined setup, specific investigations of lung tissue dynamics, i.e. alveolar volume changes and fiber length distension, become feasible and can be used to enhance the understanding for underlying physiological processes during respiration.
For more information see recent Article. Courtesy of Maria Gaertner from the Technical University of Dresden.