This chapter provides a comprehensive overview of the recent advancements in PET/CT hybrid imaging, with a particular focus on the evolution from traditional whole-body PET/CT systems to the emerging total body PET (TB-PET) technology. After a short introduction on traditional PET/CT systems, the chapter examines the key technological improvements that sets apart the most recent systems, in terms of system design and performances, image quality, and the overall potential in patient examination. The chapter delves in particular into the critical components of modern PET/CT systems, including axial field of view expansion, detector sensitivity and design, image reconstruction algorithms, and motion artifact correction. These advancements aim to address the growing demands of personalized medicine, where faster, more accurate imaging is essential for mapping and quantifying complex physiological processes. The authors also explore the integration of system performance and data processing, highlighting the challenges of incorporating these innovations into clinical practice. Special attention is given to the clinical and research applications of TB-PET, emphasizing its impact on daily use and best practices for technicians. The chapter also addresses the importance of quality control measures and acceptance testing to ensure the reliability and consistency of these advanced imaging systems.