ABSTRACT
Across a range of applications, there has been a steady trend toward tomographic imaging at ever shorter time-scales. In medical imaging, the main driver for high-speed CT has been cardiac imaging, with the aim of producing tomographic images of a beating heart (Hurlock et al. 2009). In industrial process monitoring, a key goal has been in situ imaging of flow in pipes, with the specific problem of three phase (oil, gas, water) flows in the petroleum industry being of special interest (see also Section III, Chapter 45). The development of laboratory systems has been motivated by applications in experimental fluid dynamics, such as the study of fluid and granular flow and mixing, in materials science, such as the study of dynamic processes including the development of cracks and changes in the microstructure of materials due to heating and cooling (Maire and Withers 2014), and in oil and gas exploration, such as imaging flow through porous media. As imaging systems have become faster, this has enabled development of new experimental techniques; it has also created significant challenges, both for the design and engineering of the CT system hardware, and also mathematical and computational challenges for reconstruction of the resulting tomographic images.
