MÖNCH detector enables fast and low-dose free-propagation phase-contrast computed tomography of in situ mouse lungs

Abstract

Due to the complexity of the underlying pathomechanism, in vivo mouse lung-disease models continue to be of great importance in preclinical respiratory research. Longitudinal studies following the cause of a disease or evaluating treatment efficacy are of particular interest but challenging due to the small size of the mouse lung and the fast breathing rate. Synchrotron-based in-line phase-contrast computed tomography imaging has been successfully applied in lung research in various applications, but mostly at dose levels that forbid longitudinal in vivo studies. Here, the novel charge-integrating hybrid detector MÖNCH is presented, which enables imaging of mouse lungs at a pixel size of 25 µm, in less than 10 s and with an entrance dose of about 70 mGy, which therefore will allow longitudinal lung disease studies to be performed in mouse models.

Keywords: charge-integration detector; low dose phase-contrast computed tomography; mouse-lung imaging.

Figure 1

Imaging results for an in situ mouse lung: data acquired in 10 s, sample-to-detector distance 142 cm, E = 22 keV, pixel size = 25 µm. (a) Reconstructed raw data of a central slice through the lung (field of view ∼1 cm × 1 cm × 0.4 cm). A high noise level but also strong phase effects are visible. (b) The same slice reconstructed after single distance phase retrieval (delta-to-beta ratio of 1950). Lung septum, bigger air-filled spaces (bright), vessels and soft tissue (dark) are displayed. (c) The projected minimum over ten slices shows vessels (white arrowhead) and soft tissue. (d) The projected maximum over ten slices displays airways (black arrowhead). (e) Volume rendering representation, virtually cut to show airways (grey) and vessels and soft tissue (red).