Personal Exposure Prescription Method Reduces Dose in Radiography

PURPOSE: To evaluate the effectiveness of an automatic, personalized exposure prescription method designed to reduce radiation dose during radiography examinations. METHODS: Using standard imaging parameters of average-sized patients, the authors measured individual body-part thicknesses or imaging regions of 116 patients (69 men, 47 women) and calculated each patient's exposure amount according to the thickness of the part or region. The data were used to develop each patient's personalized exposure prescription. Using the personalized exposure prescriptions, authors acquired chest images of the patients on a Carestream DRX-Revolution mobile digital radiography system. RESULTS: All images acquired using the personalized exposure prescription method were satisfactory for diagnosis; exposure indexes were above 1300, a figure deemed acceptable for diagnosis by the manufacturer. The personalized exposure method reduced the amount of radiation each patient received. DISCUSSION: Variation of tube voltage alone can control patients' exposure levels; however, using the personalized exposure prescription method eliminates the need to use automatic exposure controls. CONCLUSION: The personalized exposure prescription method is an effective tool for reducing radiation to patients during radiography as well as for eliminating dose creep.