Reference Values for Diagnostic Radiology: Application and Impact

Abstract

Reference values (RVs) are recommended by the American Association of Physicists in Medicine for four radiographic projections, computed tomography, fluoroscopy, and dental radiography. RVs are used to compare radiation doses from individual pieces of radiographic equipment with doses from similar equipment assessed in national surveys. RVs recommended by the American Association of Physicists in Medicine have been developed from the Nationwide Evaluation of X-ray Trends survey performed by the state radiation protection agencies with the cooperation and support of the U.S. Food and Drug Administration, the Conference of Radiation Control Program Directors, and the American College of Radiology. The RVs selected by the American Association of Physicists in Medicine represent, approximately, the 80th percentile of the survey distributions. Consequently, equipment exceeding the RVs is using higher radiation doses than is 80% of the equipment in the surveys. Radiation doses for specific projections, with standard phantoms, should be measured annually, as recommended by the American College of Radiology. When the RVs are exceeded, the medical physicist should investigate the cause and determine, in cooperation with the responsible radiologist, whether these doses are justified or the imaging system should be optimized to reduce patient radiation doses. RVs are a useful tool for comparing patient radiation doses at institutions throughout the United States and for providing information about radiographic equipment performance.

Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source

“…The dose of 33.9 mGy used in our experiment is significantly higher than the surface dose of 0.25 mGy used in a conventional clinical chest radiograph (41). A reduction of the number of phase steps and binning, simulating a reduced exposure time and larger pixel size, yielded low-dose dark-field results, which are comparable to the oversampled dataset (Fig.…”

Assessment of Patient Doses in CR Examinations Throughout a Large Health Region

“…Values are derived from large surveys, taken as either the 75th [12][13][14] or 80th [15] percentile of effective dose range. An examination dose above these percentiles is deemed excessive and should be reduced.…”

Radiation exposure in patients with subarachnoid hemorrhage: a quality improvement target

“…Rather than relying on parameters such as mAs, kVp, and pitch, the use of CTDI vol provides a single "dose metric" by which users can benchmark the prescribed output for a given exam against national averages, already having the effects of pitch, detector collimation, xray tube to isocenter distance, and other technical parameters all taken into account 64 . The values of CTDI vol displayed on the user console prior to scan initiation can be compared to published values, such as reference values provided by the American College of Radiology (ACR) and AAPM 64,65 , and results of national surveys, such as the Nationwide Evaluation of X-ray Trends (NEXT) study conducted by the Center for Devices and Radiological Health (CDRH). Users prescribing doses above references values should have an appropriate justification 66 .…”