The role of molecular imaging in modern drug development

•Molecular imaging improves drug development efficiency and shortens timings.•Molecular imaging can play an important part most phases of drug development.•High sensitivity nuclear imaging detects less than 10−12m probe in vivo.•Molecular imaging is crucial and strengthens the personalized medicine concept.•Molecular imaging reduces the number of animals required for drug testing (3Rs policy). Drug development represents a highly complex, inefficient and costly process. Over the past decade, the widespread use of nuclear imaging, owing to its functional and molecular nature, has proven to be a determinant in improving the efficiency in selecting the candidate drugs that should either be abandoned or moved forward into clinical trials. This helps not only with the development of safer and effective drugs but also with the shortening of time-to-market. The modern concept and future trends concerning molecular imaging will assumedly be hybrid or multimodality imaging, including combinations between high sensitivity and functional (molecular) modalities with high spatial resolution and morphological techniques.