Effects of Projections on Radiation Dose for and Image Quality of Chest Digital Radiography for Children

Background: Until now few studies have specially validated whether the sex, body mass index, or imaging projections of pediatric patients undergoing chest Digital Radiography (DR) affect the radiation dose and image quality. Introduction: To investigate the impact of different photography positions on radiation dose for and image quality of chest DR for 3-4-year-old children. Methods: One-hundred twenty 3-4-year-old patients who required chest DR were included. The patients were divided into 3 groups, with 40 patients in each group: supine Anterior-Posterior Projection (APP), standing APP and posterior-anterior projection (PAP). The Dose Area Product (DAP) and Entrance Surface Dose (ESD) values for every patient were recorded after each exposure. The Visual Grading Analysis Score (VGAS) was used to evaluate image quality. Results: The DAP and ESD values for the standing PAP and APP groups were significantly lower than those for the supine APP group (0.19 ± 0.04 dGy cm² and 0.05 ± 0.01 mGy vs. 0.25 ± 0.05 dGy cm² and 0.08 ± 0.01 mGy, P<0.05, respectively). Additionally, the VGAS for the standing APP group was significantly lower than those for the standing PAP and supine APP groups (28.58 ± 0.96 vs. 29.08 ± 0.94 and 29.03 ± 0.80, P<0.05, respectively), whereas the pulmonary field area for the standing PAP group was significantly higher than those for the standing and supine APP groups (118.95 ± 16.81 cm2 vs. 105.65 ± 14.76 cm² and 105.24 ± 16.32 cm², P<0.05, respectively). However, there were no statistically significant differences in DAP, ESD, VGAS, pulmonary field area and body mass index between the male and female patients in the three groups (P>0.05, respectively). Conclusion: The standing PAP should be the first projection choice for chest DR for 3-4-year-old children; compared with the supine and standing APP, the standing PAP may improve image quality and decrease the required radiation dose.