Susanna I.Lee1 FelixS.Chew1' 2 OBJECTIVE. We soughtto developquantitativemethodsto describethe useand results of imaging studies in emergency department patients.MATERIALS AND METHODS. A computerizednonrelationaldatabasecontaining records of 3.5 million diagnostic reports generated by our radiology department from 1988 to 1997 was queried using Boolean and natural language search tools. Each record contained data fields for patient demographics, examination description and billing code, names of interpreting radiologists and referring physicians, patient history, report body, and report impression.RESULTS. Emergencydepartment admissions andimagingstudieswere stablefrom 1991 to 1997, averaging 60,000 and 52,000 per year, respectively. Bone radiographs comprised 45.1% of examinations; chest radiographs, 44.6%; and abdominal radiographs, 10.4%. The