Scintillating crystals have been for a long time developed as a basic component in particle detectors with a strong spin-off in the field of medical imaging. A typical example is BGO, which has become the main component of PET scanners since the large effort made by the L3 experiment at CERN to develop low cost production methods for this crystal. Systematic R&D on basic mechanism in inorganic scintillators, initiated by the Crystal Clear Collaboration at CERN 10 years ago, has contributed not to a small amount, to the development of new materials for high energy physics and for a new generation of medical imaging devices with increased resolution and sensitivity. The examples of the lead tungstate crystal for the CMS experiment at CERN (high energy physics) as well as of new materials under development for medical imaging will be described with an emphasis on the mutual benefit both fields can extract from a common R&D effort.