Abstract: Medicine is dramatically changing as we approach the year 2020. The rapid expansion in biomedical knowledge and the explosion in medical data (“big data”) require physicians, more than ever, to have “20/20” insight into the symptoms, diseases, and best treatments for their patients. This lecture will introduce the new paradigm of “data-driven medicine” and how computational methods of informatics can help physicians to leverage the data deluge to practice precision medicine. We will focus specifically on one type of medical data—radiological imaging—and show how medical practice and research are being transformed by the accumulation of large amounts of these data, both within hospitals and in cyberspace, and how the computational methods of informatics can enable physicians to deliver more tailored care to their patients. We will present an example in which computers assist physicians to extract and summarize quantitative features in images to help them to choose the best therapeutic strategies.