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The periodic assessment of exposures in diagnostic radiology is an important part of a comprehensive quality assurance program. The most frequent radiologic examination conducted in the United States is chest radiography. Automatic exposure controlled (AEC) techniques are often used for this exam, and a standard patient-equivalent chest phantom is useful when estimating patient exposures on such systems. This is of particular importance if exposures are to be compared among AEC systems with different entrance x-ray spectra. Such a phantom has been developed to facilitate surveys of the average patient exposure from AEC posteroanterior chest radiography. The phantom is relatively lightweight and easily transportable, sturdy and made of readily available and relatively inexpensive materials (Lucite and aluminum). It accurately simulates the primary and scatter transmission through the lung-field regions of a patient-equivalent anthropomorphic phantom for x-ray spectra typically used in chest radiography. A clinical evaluation has been conducted to verify the patient equivalence of the phantom. Measurements of patient entrance skin exposure were obtained for a large number of patients on a variety of x-ray systems operated in the AEC mode using one or both lung-field detectors. Comparison of these data with exposure estimates derived from the phantom indicate that the phantom attenuates the x-ray beam in such a way that it can be employed to accurately and consistently estimate the mean exposure of the average patient under a variety of radiographic conditions. The design, development, and evaluation of the patient-equivalent attenuation phantom is described.

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The American College of Radiology Mammography Accreditation Program (ACR MAP) reviews both clinical mammograms and a phantom image to assess clinical and technical quality from each mammography unit. The phantom contains details representing fibers (speculations), speck groups (microcalcifications), and masses. The depiction of these structures by the mammographic system is scored by medical physicists. The phantom image is taken using the facility's exposure technique for a 4.2‐cm thick breast of average composition. The mean glandular dose (MGD) is determined from a set of thermoluminescent dosimeters placed on top of the chest wall edge of the phantom. Phantom scores and MGD data collected from 1993 to 1999 based on 31 535 unit evaluations are presented in this paper. The relationship between the failure rate for phantom image quality and MGD has been analyzed. While over all doses the phantom failure rate was 11%, for doses of 0.26 to 0.50 mGy the failure rate was 43%. The phantom failure rate fell continuously to about 6% for MGDs in the range of 1.51–2.0 mGy. With further increases in dose, failure rates began to rise. Factors that may account for these results are presented and discussed.