The role of imaging in drug development.

The role that imaging plays as a biomarker in the discovery and development of novel therapies has grown in recent years. Imaging is now a widely used in both the preclinical and clinical stages of development, close attention is now paid to the translational relevance of imaging data in an effort to make key decisions earlier. This article describes the use of imaging as a biomarker to demonstrate proof of target, mechanism, or efficacy. Examples are provided to show the types of information that can be gathered and a sense of the size of clinical trial that is required to obtain data for each category.