Non-Invasive Microstructure and Morphology Investigation of the Mouse Lung: Qualitative Description and Quantitative Measurement

Abstract

BackgroundEarly detection of lung cancer is known to improve the chances of successful treatment. However, lungs are soft tissues with complex three-dimensional configuration. Conventional X-ray imaging is based purely on absorption resulting in very low contrast when imaging soft tissues without contrast agents. It is difficult to obtain adequate information of lung lesions from conventional X-ray imaging.MethodsIn this study, a recently emerged imaging technique, in-line X-ray phase contrast imaging (IL-XPCI) was used. This powerful technique enabled high-resolution investigations of soft tissues without contrast agents. We applied IL-XPCI to observe the lungs in an intact mouse for the purpose of defining quantitatively the micro-structures in lung.FindingsThe three-dimensional model of the lung was successfully established, which provided an excellent view of lung airways. We highlighted the use of IL-XPCI in the visualization and assessment of alveoli which had rarely been studied in three dimensions (3D). The precise view of individual alveolus was achieved. The morphological parameters, such as diameter and alveolar surface area were measured. These parameters were of great importance in the diagnosis of diseases related to alveolus and alveolar scar.ConclusionOur results indicated that IL-XPCI had the ability to represent complex anatomical structures in lung. This offered a new perspective on the diagnosis of respiratory disease and may guide future work in the study of respiratory mechanism on the alveoli level.

Dose optimization approach to fast X-ray microtomography of the lung alveoli

“…So far, all studies either were performed in two dimensions only or suffered from low temporal and spatial resolution; high-resolution lung images in three dimensions, on the other hand, were successfully obtained only for static samples (Schittny et al, 2008;Yong et al, 2009;Haberthü r et al, 2010;Mokso et al, 2011;Zhang et al, 2011). Thus, in vivo X-ray tomography with micrometre spatial and sub-second temporal resolution remains a challenge and many open questions in the study of lung physiology remain unanswered.…”

Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source

“…Multiple air-tissue interfaces present in the inflated lung result in a high degree of X-ray phase contrast and low absorption contrast. Among the phase-contrast imaging methods available-namely, interferometric methods, propagation-based methods, and analyzer-based methods-the latter two were intensively studied in lung imaging (9,13,14).…”

Histochemical analyses and quantum dot imaging of microvascular blood flow with pulmonary edema in living mouse lungs by “in vivo cryotechnique”

“…In adult mice, more than 80% of total alveoli measured 100-200 lm in diameter in inspiratory lung tissue sections and 30-100 lm diameter in expiratory lung tissue sections (data not shown), which were almost similar to those in cat lungs . Previously, Zhang et al (2011) already reported that the diameters of alveoli, containing about 90% air at maximum air capacity, were about 65-170 lm using in-line X-ray phase contrast imaging of 1-day-old dead mice. Therefore, sizes of alveoli obtained from adult mice in our data were compatible with those in previous reports (Irvin and Bates 2003;Kitchen et al 2005;Zhang et al 2011).…”