Age-dependent evaluation of organ and effective doses in pediatric full-spine radiography; Influence of anteroposterior and posteroanterior projection and copper filtration using Monte Carlo simulation

Katsunuma, Yasushi*; Sato, Kaoru   

In pediatric scoliosis, repeated whole-spine radiography is performed for follow-up, resulting in increased exposure to organs located in the anterior torso. Therefore, optimizing the radiography protocol is essential. In this study, we simulated whole-spine radiography using pediatric University of Florida phantoms and PHITS. We analyzed the effects of a copper filter and the direction of radiography (anterior: AP, posterior: PA) on organ doses. Compared with AP radiography, PA radiography increased doses to the kidneys and red bone marrow located in the posterior torso, while doses to the breast and thyroid located in the anterior torso were reduced by approximately 80-93%, and effective doses were also halved. Furthermore, the use of a copper filter reduced organ doses by approximately 5-19%. These findings suggest that PA radiography using a copper filter, while considering organ positions that change with age, is a useful radiography protocol for reducing exposure doses in pediatric whole-spine radiography.