Exploration of exposure dose optimization for pelvic examination in direct digital radiography with a phantom

Objective: To investigate the relationship between exposure dose and image quality for a direct digital radiography system and to determine the optimum exposure parameters for pelvic examination. Methods: A contrast-detail phantom CDRAD2.0 was exposed to different doses and the IQF of phantom images were calculated. The optimum exposure parameters were determined by ANOVA and SNK analysis. The image of an anthropomorphic phantom taken with optimized exposure parameters was verified using CEC image criteria. Results: The IQF of the images of CDRAD2.0 phantom was significantly different for different doses, as the exposure dose was greater than 0.61 mGy. The IQFs have no difference for different dose groups. The image quality between this optimized exposure dose and conventional exposure dose not was significantly different. Conclusion: The image quality of direct digital radiography system is improved as the exposure dose increases, and as the exposure dose exceeds a certain threshold, the image quality will not change apparently. There is an optimum exposure dose and the optimized exposure dose for the researched phantom is 0.61 mGy. (authors)