Abstract
A clinical X-ray CT scanner is an instrument that is used to observe our bodies non-invasively, using the distribution of the linear absorption coefficient. However, X-ray irradiation energy and its spatial resolution are not suitable for the visualization of small objects. Further development and optimization of measurement techniques have led to the development of an X-ray micro-CT scanner for the visualization of small specimens with diameters of a few mm. A technique called refraction-contrast imaging was developed to facilitate the visualization of soft tissue structures, and has become more widely used over time. In this review, the history of X-ray imaging is briefly recounted, and the applicability of these techniques to plant biological research is summarized. In addition, we introduce the authors' works related to these techniques.
