Translational imaging in toxicology

In vivo imaging has a potential to bring innovation to translational toxicology for drug discovery. This includes magnetic resonance imaging, positron emission tomography (PET), single photon emission tomography, and computed tomography. The utility of imaging comes from its capacity to provide minimally invasive biomarkers for safety profiling and decision-making in drug discovery. Nonspecific biomarkers, such as magnetic resonance imaging relaxometry, computed tomography density, or PET ¹⁸F-fluoro-2-deoxy-d-glucose are better suited for preclinical general toxicology and clinical monitoring, while specific ones, such as most of PET and single photon emission tomography ligands, are better suited to clarify mechanisms of toxicity or unwanted target engagement. However, the use of these biomarkers is sporadic and governed by scientific interest and availability rather than its utility. A systematic approach is needed to qualify these biomarkers with regulatory authorities so translational imaging could be incorporated into drug development and its unique potential translated into safer and cheaper medicines.