The principle of dual-energy x-ray grating phase-contrast imaging(DEPCI) is clarified by using the theory of x-ray interference and Fresnel diffraction. A new method of retrieving phase from the two interferograms is ...The principle of dual-energy x-ray grating phase-contrast imaging(DEPCI) is clarified by using the theory of x-ray interference and Fresnel diffraction. A new method of retrieving phase from the two interferograms is proposed for DEPCI,and its feasibility is verified via simulation. Finally, the proposed method applied to DEPCI experiment demonstrates the effectiveness of the method. This paper lays the theoretical foundation for performance optimization of DEPCI and the further integration of DEPCI and computed tomography.展开更多
Objective. To study the whole body bone mineral changes in normal subjects.Methods. Bone mineral was measured by dual X-ray absorptiometry(DXA) in 292 normal subjectsaged 10～79 years, including 152 females and 140 ma...Objective. To study the whole body bone mineral changes in normal subjects.Methods. Bone mineral was measured by dual X-ray absorptiometry(DXA) in 292 normal subjectsaged 10～79 years, including 152 females and 140 males. They were divided into age-groups by decade.Results. In males, the ages with peak value of total bone mineral content (TBMC), total bone min-eral density (TBMD), anteroposterior spine BMD(L2-4 BMD) were in the 30～39,20～39, 20～29 age-groups respectively. In females, they were all in the 30～39 age-group. Peak values of TBMC, TBMD,L2-4 BMD were higher in males than those in females. Loss of bone mineral for females was more pro-nounced than that for males. Loss of L2-4 BMD was more pronounced than TBMD.Conclusion. This study provides the normal bone mineral data of whole body for males and females,and the characteristic of changes.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61405144)the Natural Science Foundation of Tianjin,China(Grant No.15JCQNJC42100)the Technology Special Commissioner Project of Tianjin,China(Grant Nos.16JCTPJC47200 and 16JCTPJC48100)
文摘The principle of dual-energy x-ray grating phase-contrast imaging(DEPCI) is clarified by using the theory of x-ray interference and Fresnel diffraction. A new method of retrieving phase from the two interferograms is proposed for DEPCI,and its feasibility is verified via simulation. Finally, the proposed method applied to DEPCI experiment demonstrates the effectiveness of the method. This paper lays the theoretical foundation for performance optimization of DEPCI and the further integration of DEPCI and computed tomography.
文摘Objective. To study the whole body bone mineral changes in normal subjects.Methods. Bone mineral was measured by dual X-ray absorptiometry(DXA) in 292 normal subjectsaged 10～79 years, including 152 females and 140 males. They were divided into age-groups by decade.Results. In males, the ages with peak value of total bone mineral content (TBMC), total bone min-eral density (TBMD), anteroposterior spine BMD(L2-4 BMD) were in the 30～39,20～39, 20～29 age-groups respectively. In females, they were all in the 30～39 age-group. Peak values of TBMC, TBMD,L2-4 BMD were higher in males than those in females. Loss of bone mineral for females was more pro-nounced than that for males. Loss of L2-4 BMD was more pronounced than TBMD.Conclusion. This study provides the normal bone mineral data of whole body for males and females,and the characteristic of changes.
