In vivo x-ray imaging of the respiratory system using synchrotron sources and a compact light source

摘要

Bright synchrotron x-ray sources enable the capture of high-speed image sequences, both in projection andin three-dimensions via computed tomography (CT). These x-ray movies can capture how biological sampleschange with time, giving vital information about function as well as structure. The use of a synchrotron x-raysource also provides high spatial coherence, which facilitates the capture of not only a conventional attenuationbasedx-ray image, but also phase-contrast and dark- eld signals. These signals are especially strong fromair/tissue interfaces, which means that they are particularly useful for examining the respiratory system. Wehave performed a range of x-ray imaging studies that look at lung function, airway surface function, inhaled andinstilled treatment delivery, and treatment e ects in live small animal models. These have utilised a range ofoptical set-ups and phase-contrast imaging methods in order to be sensitive to the relevant sample features, andbe compatible with high-speed imaging. For example, we have used a grating interferometer to measure how theair sacs in the lung inate during inhalation, via changes in the dark- eld signal; a single-exposure, single-gridset-up to capture changes in the liquid lining of the airways; and propagation-based phase contrast to imageclearance of inhaled debris. Studies have also utilised a range of analysis methods to extract how the samplefeatures change within a time-sequence of two-dimensional projections or three-dimensional volumes. Whilethese imaging studies began at large-scale facilities such as the SPring-8 and Australian synchrotrons, we havealso recently performed these kinds of studies at a compact synchrotron based on the inverse-Compton e ect, atthe Munich Compact Light Source (MuCLS).