In the past two decades, medical imaging has experienced an unprecedented explosion in its capacity to generate information concerning patients. It is hard to imagine that only 20 years ago medical imaging was confined to radiography, fluoroscopy, static imaging with radiopharmaceuticals, and bistable sonographic systems. At that time the following imaging technologies were not present in the clinical arena: CT, gray-scale and real-time sonography, Doppler sonography, single-photon and positron-emission tomography, interventional angiography, digital subtraction angiography and digital radiography, and MR imaging. Rather primitive equipment was used routinely for mammography and angiography, and computers were viewed as a novelty for researchers rather than as integral components of imaging systems. In many ways the evolution of medical imaging from a craft into a science in the past two decades is the result of the integration of computers into the technology of imaging. Today, radiology is leading medicine into the modern era of information generation by computer-dominated electronic systems. The ability of modern radiologists to generate information about patients is nothing short of spectacular, and the pivotal role of imaging services in patient care is a reflection of this ability. Although growth in the production of radiologic information has been astounding, little has changed in the way that the information is managed and used in the clinical arena. Most physicians still request imaging studies on printed forms, and most radiologists still interpret the studies from hard-copy images, usually on film. Studies are still stored in and retrieved from a hard-copy file room full of film folders and typed records. This approach to information management in radiology was seriously deficient 20 years ago; today it is a disaster. Twenty years ago, interpretive and consultative services in radiology were compromised by lost films and inefficient processes for retrieving and displaying radiologic information. Today, with many more studies of various types often performed in each patient and reduced tolerance of referring physicians and administrators for inefficiency and dalliance, traditional mechanisms for managing information in radiology are outmoded and unresponsive to the needs of patients and physicians [1].