Aniță, Dragoș-ConstantinAniță, Adriana-Elena2026-06-162026-06-1620251454-7406https://repository.iuls.ro/handle/20.500.12811/6646The IVIS Spectrum (PerkinElmer) represents a benchmark platform for non-invasive, quantitative optical imaging in small-animal models and has become an essential tool in translational biomedical and veterinary research. By integrating ultrasensitive bioluminescence and fluorescence detection with advanced spectral unmixing and threedimensional tomographic reconstruction, the system enables longitudinal, in vivo monitoring of molecular and cellular processes with high spatial and temporal resolution. This review provides a comprehensive synthesis of the physical principles underlying IVIS Spectrum technology, critically evaluates its major applications in oncology, infectious diseases, inflammation, and regenerative medicine, and discusses its contribution to the implementation of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation. Particular emphasis is placed on the operational use of the IVIS Spectrum system at the ROVETEMERG Research facility, highlighting its role in complex oncology and infectious disease models relevant to veterinary medicine and the One Health paradigm.EnglishAttribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)http://creativecommons.org/licenses/by-nc-sa/4.0/IVIS Spectrumin vivo optical imagingbioluminescence imagingfluorescence imagingveterinary researchpreclinical modelsArticle2393-4603https://doi.org/10.61900/SPJVS.2025.04.18