New fast-imaging MRI systems designed specifically for cardiac magnetic resonance enable new applications of noninvasive vascular imaging. The use of functional MRI and diffusion tensor imaging to map brain function and structure offers a new dimension to an understanding of the human condition. Clinical applications of functional MRI will influence many specialties including surgery, education, and rehabilitation. Functional imaging has the potential to visualize the regional concentration of specific proteins. This imaging at the level of molecules may be possible by use of a contrast material whose signal is changed by local enzymatic activity. The three-dimensional digital data collected in modern imaging techniques allow for virtual endoscopy in the respiratory, alimentary, and cardiovascular systems. Virtual endoscopy may replace many of the more invasive diagnostic methods in the near future. The measurement of clinical decision-making through observer performance studies better informs both the physician and the patient on how to improve upon the quality of clinical practice. These prospects for progress reinforce diagnostic imaging as a cornerstone in medical informatics. The history of creating images used in medicine reveals the invention of diagnostic tools which may provide new information but premature use can result in improper application of a poorly understood technology. Research into the use of new technology may be as important as the technology itself in improving the human condition.