Imaging as a tool in drug development.

Medical imaging has experienced a huge increase in exploratory technologies over the past 20 to 30 years. From drug discovery to drug development to routine clinical practice, the advent of functional imaging is about to revolutionize both medicine and pharmaceutical drug development. Currently, a number of technologies are in competition. Positron emission tomography (PET) and magnetic resonance imaging (MRI) have advanced furthest as useful adjuncts to clinical drug development, even though data from both remain, at best, biomarkers that alone will not suffice for regulatory approval. However, the high-risk proof-of-concept and early proof-of-efficacy trial programs can be accelerated with judicious use of PET or MRI. The U.S. Food and Drug Administration (FDA) is currently working to establish guidelines for these new imaging methods, which might accelerate drug development and improve treatment of individual patients.