The purpose of this scan was to better understand the structure of the Acinus of murine lungs and to provide a comprehensive and quantitative analysis of the respiratory system at the alveolar level. Another aspect is to provide data for stereological analysis and collect measurements of such parameters as density, parenchymal fraction and alveolar count. Because the scan was nondestructive, further study of the lungs is possible.
The subject of the scan is a set of mouse lungs that have been inflated and fixated to preserve the lungs in their inflated state. The scan is part of the wider study to provide a complete atlas of the respiratory system in mice and provides an elegant technique to study the smaller airways and respiratory structures without needing to resort to morphology and allows the non destructive study of murine lungs.
About the Scan
Each lung specimen is prepared using a similar protocol. The lungs are initially scanned in-vivo at different pressures. The lungs are fixed through perfusion using a modified Heitzman solution at 20cm pressure, following an initial pre-flush. The lungs are air-dried at 20cm pressure, 37 c temperature for 3 days and are scanned periodically to ensure preservation of shape and volume.Each LFOV scan is performed as the first step in identifying acinar locations for high resolution imaging. The settings for the LFOV scan are chosen such that identification of probable locations of acinii is possible by visually inspecting images. Magnification and image quality at that level of magnification is the deciding factor in setting parameters. The high resolution scans are conducted on the specific locations and the parameters are now decided by using not only image quality as a factor, but also the FOV to assure that an acinus is completely captured in the scan. The clear demarcation of alveolar walls is a necessity for analysis and the settings are chosen such that the resolution of the images is sufficient to capture the edge details accurately.