New exposure indicators for digital radiography simplified for radiologists and technologists.

OBJECTIVE: The purpose of this article is to educate radiologists and technologists about the clinically relevant portion of the new digital radiography standards. CONCLUSION: Both the International Electrotechnical Commission (IEC standard 62494-1) and the American Association of Physicists in Medicine (AAPM Task Group 116) have developed similar standards for monitoring exposure in digital radiography to eliminate proprietary and confusing terminology. Radiologists and technologists will need to learn three new terms--exposure index, target exposure index, and deviation index--to understand the new standards.

Quality assurance: using the exposure index and the deviation index to monitor radiation exposure for portable chest radiographs in neonates.

BACKGROUND: Many methods are used to track patient exposure during acquisition of plain film radiographs. A uniform international standard would aid this process. OBJECTIVE: To evaluate and describe a new, simple quality-assurance method for monitoring patient exposure. This method uses the "exposure index" and the "deviation index," recently developed by the International Electrotechnical Commission (IEC) and American Association of Physicists in Medicine (AAPM). The deviation index measures variation from an ideal target exposure index value. Our objective was to determine whether the exposure index and the deviation index can be used to monitor and control exposure drift over time. MATERIALS AND METHODS: Our Agfa workstation automatically keeps a record of the exposure index for every patient. The exposure index and deviation index were calculated on 1,884 consecutive neonatal chest images. Exposure of a neonatal chest phantom was performed as a control. RESULTS: Acquisition of the exposure index and calculation of the deviation index was easily achieved. The weekly mean exposure index of the phantom and the patients was stable and showed <10% change during the study, indicating no exposure drift during the study period. CONCLUSION: The exposure index is an excellent tool to monitor the consistency of patient exposures. It does not indicate the exposure value used, but is an index to track compliance with a pre-determined target exposure.