Options for radiation dose optimisation in pelvic digital radiography: A phantom study

Abstract Purpose To investigate the effects of phantom orientation and AEC chamber selection on radiation dose and image quality (IQ) for digital radiography (DR) examinations of the pelvis. Methods A phantom study was conducted using a DR detector, utilising all AEC chamber combinations. Current recommended orientation (Cr-AEC) was with the outer AEC chambers cranially orientated. mAs (given), source-to-skin distance and kV p data facilitated entrance surface dose and effective dose calculations. Six anatomical areas were blindly graded by two observers (3-point scale) for IQ. Statistical differences in radiation dose were determined using the paired Student's t -test. IQ data was analysed for inter-observer variability (ICC) and statistical differences (Wilcoxon test). Results Switching phantom orientation (caudally orientated outer AEC chambers: Ca-AEC) reduced mean radiation dose by 36.8%, ( p p p p Conclusion Switching pelvic orientation relative to AEC chamber position can optimise radiation dose during pelvic radiography. AEC chamber position should be clearly marked on equipment to facilitate this. AEC selection should be an active process.