The Consistency of Exposure Indicator Values in Digital Radiography Systems

After years of establishment of computed radiography (CR) and digital radiography (DR), manufacturers have introduced exposure indicator (EI) as a feedback mechanism for patient dose. However, El consistency is uncertain for CR. Most manufacturers recommended El values in a range of number for all examination, instead of giving the exact range for a specific body part, raising a concern of inappropriate exposure given to the patient in clinical practice. The aim of this study are to investigate the exposure index consistency in digital radiography systems produced in constant exposure parameters and clinical condition and to determine the interaction between the anatomical part and EI. A phantom study of skull, chest, abdomen and hand was carried out to determine the effect of anatomical part on EI. Four systems were used for comparison - Fuji CR, Carestream CR, Siemens DR and Carestream DR. For each projection, the phantom positioning and exposure parameters were set according to the standard clinical practice. All exposure parameters and clinical conditions are kept constant.