Evaluation of dose–image-quality optimization in digital chest radiography

In this study, we aimed to evaluate the operation conditions and reduce patient doses while maintaining acceptable image quality in digital chest radiography. A geometric chest phantom with built-in regional test objects for quantitative assessment of image quality was used to produce images that simulate a chest projection. Images of the chest phantom were obtained using a GE Revolution XR/d digital X-ray system operated at tube potentials from 62 to 132 kVp with the grid and a distance of 180 cm between the source and image system. The X-ray images were obtained with the automatic exposure control (AEC) mode. Raw data of the acquired images were used for image-quality analysis. The signal-to-noise ratio (SNR) was used as an image-quality indicator and a figure of merit (FOM) computed by dividing the SNR2 by the effective dose was used to estimate the optimization of the chest radiography. The routine operation tube potential of 112 kVp seems optimal for subdiaphragm examinations but not for lung and heart examinations.