Abstract: ［Abstract］Objective〖HTSS〗To investigate the application value of copper additional filtration with different thickness in bone digital radiography（DR）.
Methods〖HTSS〗The equivalent phantom of the human body was used for bone DR. The thick parts such as head, spine and pelvis were examined as automatic exposure control（AEC） group by AEC system using the ionization chamber.The thin parts such as limbs and joints without AEC were examined as non-AEC group. The copper additional filters with different thickness of 0.1 mm, 0.2 mm and 0.3 mm were selected for exposure. The surface incident dose, imaging quality score and tube current of different thickness copper additional filter groups were compared.
Results〖HTSS〗There were significant differences in the surface incident dose of four different thickness copper additional filters in non-AEC group. By pairwise comparison, the surface incident dose without additional filtration was greater than 0.1 mm, 0.2 mm and 0.3 mm copper additional filtration respectively, while the surface incident dose of 0.1 mm copper additional filtration was greater than 0.3 mm copper additional filtration, with statistically significant difference(P＜0.05). In non-AEC group, there were no significant differences in imaging quality scores and tube current of four different thickness copper additional filters(P＞0.05). There were significant differences in the surface incident dose and the tube current of four different thickness copper additional filters in AEC group. By pairwise comparison, the surface incident dose without additional filtration was greater than 0.3 mm copper additional filtration, while the tube current was less than 0.3 mm copper additional filtration, the difference was statistically significant(P＜0.05). In AEC group, there were no significant differences in imaging quality scores of four different thickness copper additional filters(P＞0.05).
Conclusion〖HTSS〗The copper additional filtration can reduce the examination dose of skeletal system DR effectively on the premise of ensuring the diagnostic quality, and achieve low-dose radiography of skeletal system.

Key words: skeleton； radiography； additional filtration, radiaition dose