The prevalence of diabetes is 382 million worldwide, and is expected to rise to 592 million in 2035 (http://www.idf.org/diabetesatlas); 2.5-15\% of national annual healthcare budgets are related to diabetes care, potentially increasing to 40\% in high-prevalence countries. Beta cell dysfunction and death are central events in diabetes pathogenesis, but the natural history of beta cell loss remains unknown. Clinical imaging of beta cells will play a pivotal role in developing strategies for optimized diabetes prevention and treatment.