This chapter addresses the technological parts of a CT system used for crop phenotyping. First, all of the hardware components are described and explained. Thus, it is shown how they are utilized for phenotyping purposes. After that, different system setups and ways of acquiring a CT dataset are shown. Additionally, the post processing of the generated data using specialized algorithms for segmentation is discussed. For above- and belowground phenotyping applications two different examples are shown to present the utilization of CT for crop phenotyping. With this chapter, the reader will be proficient in choosing a CT system for their individual phenotypic application and will know how future advances might affect the throughput or the resolution of the current systems.