High-resolution X-ray refraction imaging of rat lung and histological correlations

Abstract

This study was performed to observe microstructures of the rat lung, using a synchrotron radiation beam and to compare findings with histological observations. X-ray refraction images from ex-vivo ventilating rat lung were obtained with an 8 KeV monochromatic beam and 20-mum thick CsI(Tl) scintillation crystal. The visual image was magnified using a 20x microscope objective and captured using an analog CCD camera. Obtained images were compared with conventional light microscopic findings from the same tissue. Pulmonary microstructures, including alveolar ducts, alveolar sacs, alveoli, alveolar walls, and perialveolar capillary networks were clearly identified with spatial resolution of as much as 1.2 mum and had good correlation with conventional light microscopic findings. The shape of alveoli appeared more round in SR images than in the light microscopic images. The results suggest that X-ray microscopy study of the lung using synchrotron radiation demonstrates the potential for clinically relevant microstructure of lung tissue without sectioning and fixation.

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).…”

Phase Contrast Microradiography of Mouse Lung Using Synchrotron X-ray: Correlation with Optical Microscopy

“…In REI with using polychromatic X-rays,10,11 the aerated lung tissue structure of small animals was seen as a speckled pattern. Jheon et al7 observed terminal respiratory unit microstructures of rat lung ex vivo , using monochromatic X-ray REI. In this study, overall alveolar structure was identified as an overlap pattern on snapshot phase contrast X-ray images of inflated mouse lung sample.…”

“…The same is true for phase contrast imaging because the difference of refractive index between air and soft tissue is also large 3. Some studies on small animals have recently been conducted 4-7. In one study,8 the tomography of mouse and rabbit lungs was shown by the edge-enhancement effect.…”

High resolution tomographic imaging of the alveolar region of the mammalian lung

“…The brilliant, highly collimated beam provides a nearly ideal X-ray source for µCT [117], producing greater spatial resolution. This allows high-resolution imaging of unprocessed lung tissue [15,[118][119][120][121] and ultra high resolution (from <1 to 15 µm, with tissue thicknesses of 1500 µm) visualization and 3d reconstruction of small airways and alveoli in processed tissue [18,122].…”