Microscopic dual-energy computed tomography (microDECT) imaging of animal tissues: the colour of X-rays

In this view article, we present potential applications of laboratory-based spectral dual-energy X-ray microtomography imaging for ex vivo animal tissue samples. Technical details on this topic have been reported in previous work, so we focus explicitly on applications here, discussing both dual-energy imaging for the separation of mineralised tissue from one X-ray dense contrast agent, as well as the imaging of samples stained with two X-ray dense contrast agents. Examples are given for a variety of research areas, including preclinical biomedical phenotyping (vasculature, skeletal development), comparative vertebrate morphology, and invertebrate anatomy. Based on the data presented, we conclude that the use of spectral X-ray information can provide new insights into CT datasets. Although using the dual-energy approach initially requires more effort and cost in data acquisition, this additional effort is often worthwhile, as dual-energy datasets allow for more efficient data visualisation, segmentation, and analysis. Until now, software functions for acquisition and processing of dual-energy data have not been implemented in many of the software toolboxes provided by X-ray microtomography vendors with their scanners. We propose that a user-friendly implementation of software tools for acquiring and processing spectral CT data would be a big step towards a wider use of this promising and powerful imaging approach.