PHANTOMS FOR DIAGNOSTIC-RADIOLOGY

To evaluate entrance skin exposure, the United States Food and Drug Ad ministration (FDA), Center for Devices and Radiologic Health (CDRH), h as developed patient-equivalent phantoms suitable for chest, abdominal and lumbosacral spine projections. Clinical trials performed by FDA h ave established the clinical equivalency of the exit X ray spectrum fo r a 23 cm chest thickness and 21 cm abdomen patient. Similarly, cylind rical Lucite head and body phantoms for computerised (axial) tomograph y have been developed and standards for their design and use have been published in the United States Code of Federal Regulations. The FDA h as also conducted extensive surveys using these phantoms, and data is routinely published to establish a national average for comparison. Th ese four phantoms are discussed and evaluated for use in routine clini cal facilities. Their use by the European Community is suggested, and conformity, on an international scale, with existing US standards for reference is promoted.