Room: Room 207
Purpose: Patient doses can be lowered when switching from computed radiography (CR) to digital radiography (DR) detectors, but only if efforts are made in recalibrating AEC targets, updating techniques, and educating technologists. Exposure data was reviewed before and after DR panel installation to assess the efficacy of these measures in adjusting technologist practice to reduce dose to match detector technology.
Methods: Prior to installation of wireless DR panels (Agfa DR14s), one year of exposure index (EI) data was collected from 8 workstations at five sites utilizing CR (Agfa MD4.0 and HD5.0). AEC systems in all rooms were recalibrated and programmed techniques were updated and standardized across systems to match the lower detector dose requirements of DR compared to CR (2.5ÂµGy vs 3.5-4.0ÂµGy). Exposure data was exported approximately 3 months following each retrofit, yielding 133,759 CR and 39,658 DR dose statistics for analysis. Values for EI and standard deviation of deviation index (DI) for each workstation and exam group were compared for CR and DR data to assess changes in practice.
Results: Reducing AEC target detector dose was expected to decrease EI for photo-timed exams by ~28-37%. The observed reduction in EI was in-line with expectation and averaged 41%, ranging from 15%-50% depending on exam group. Manual technique exams saw an average reduction of 50%, ranging from 42-55%, depending on exam group. The standard deviation in DI was reduced for almost all exam groups except extremity work.
Conclusion: Analysis of dose statistics indicate that efforts in recalibrating AEC, updating techniques, and educating technologists were successful. Average reduction in EI for photo-timed exams was as expected, and an even larger reduction in EI for manual techniques indicate that technique charts are being adhered to. Site data allowed for troubleshooting specific areas and segmentation issues were found in several exams.