The present chapter provides an overview of hybrid imaging technologies, such as PET/CT or PET/MRI and SPECT/CT, highlighting the differences between the different modalities and the importance of efforts towards standardization to optimize their respective performance and interoperability. Therefore, pre-existing standardization frameworks, as well as current initiatives to promote consistency and compatibility between different hybrid imaging systems, were explored. Then, practical strategies to implement for the technological standardization of imaging systems, including equipment calibration, image reconstruction protocols, and data management practices are discussed. As an ultimate challenge, the development and use of innovative anthropomorphic phantoms (including for example the StepBrain brain phantom), will be encouraged and promoted to activate multicenter studies of technological harmonization between the different hybrid imaging systems.