Flexible solutions for lab-based phase contrast and dark field CT and micro-CT

Phase-based (PB) x-ray imaging (XRI) methods have grown in importance over recent years, and it can probably be argued that the majority of micro-CT experiments at synchrotrons include phase effects in some form or fashion. A comparable if not higher level of interest has consequently arisen with regards to the translation of PB XRI into lab-based CT and micro-CT system, where however things have been moving more slowly, and the opposite is probably true i.e. most acquisitions are currently non-PB. The reasons for this are multiple and varied, but the key ones may be attributable to setup complexity and to the necessity to move optical elements during acquisitions, limits in spatial resolution, and excessively long acquisition times. In the imaging of biological tissues, especially in vivo, excessive delivered dose can pose an additional concern. Based on the acceptance that a “one size fits all solution” probably does not exist, and that most real world applications typically do not require all the above features simultaneously, our group has focused on the development of a flexible approach where typically counteracting features (e.g. high spatial resolution and fast acquisition times) can be traded off, including while making use of the same imaging system after this has been designed and built. This paper briefly reviews the technical innovations that have made the above possible, presents some key results in various areas of application, and discusses areas currently undergoing further development, among which are extensions to both higher and lower energy x-ray spectra, and new approaches to multimodality and data retrieval.