KIKUCHI, K., KOWADA, M., SASANUMA, J., OGAYAMA, H. and WATANABE, K. Local Image Filing System in Neurosurgery: Validity of Selective Storage of Radiographic Images. Tohoku J. Exp. Med., 1991, 165 (1), 1-11-In an effort to achieve efficient image management in the practice of neurosurgery, a clinical data base system was designed and developed to process, store and retrieve neuroradiologic image information on hospitalized patients with the use of a local image filing system (EFPACS-500, Fuji Electric Co., Ltd). Storage and retrieval of radiographic images were studied to quantify existing procedures and to evaluate the validity of new technology. One of our hospitals (Southern Tohoku Research Institute for Neuroscience) has annually produced approximately 100, 000 sheets of film radiographs, resulting in a great deal of serious problems, particularly lack of space for storage. In addition, the overall averaged ratio of selected key films to total files of radiographs was estimated to be 16.3% for hospitalized patients during the past 5 years. It is assumed that, by means of digital storage on this selective basis, radiographic storage problems can be solved with the use of the current data base system which efficiently handles image information involving patient care. In the practical view another substantial improvement in this work is the high functionality of the system, with which radiographic images coupled with a variety of clinical data on patients can be stored in a descriptive fashion.