8. Results

Figure 6 shows each density projection image generated by the material decomposition process. A novel DE virtual monochromatic image processing is performed from a density projection image, and Figures 7 and 8 show the image generated by each reconstruction algorithm.

Figure 6. DE material decomposition straight projection images. The DE material decomposition projections for CaCO3, epoxy, and PMMA were window level = 0.59 and window width = 0.26, window level = 0.69 and window width = 0.33, and window level = 0.21 and window width = 0.24, respectively.

Figure 8. Comparisons among the polychromatic (P) and virtual monochromatic (VM) images with each IR algorithm (P MLEM: Window level = 0.32, window width = 0.17; VM MLEM: Window level = 0.25, window width = 0.12; P&VM SART:

State-Of-The-Art X-Ray Digital Tomosynthesis Imaging http://dx.doi.org/10.5772/intechopen.81667 81

Figure 9. Comparisons of the CNR of the in-focus plane images obtained by using each reconstruction algorithm with

polychromatic and virtual monochromatic image processing (CaCO3; 15 mm ϕ, 175 mg/ml).

Window level = 0.22, window width = 0.37; P&VM SART-TV: Window level = 0.24, window width = 0.34).

Figure 7. Comparisons among the polychromatic (P) and virtual monochromatic (VM) images acquired by using the FBP reconstruction algorithm (window level = 0.05, window width = 0.11).

State-Of-The-Art X-Ray Digital Tomosynthesis Imaging http://dx.doi.org/10.5772/intechopen.81667 81

photon statistics, the electronic noise from the results, and the structural noise that could obscure the object. The sizes of all regions of interest (ROIs) used to measure the CNR were

Figure 6 shows each density projection image generated by the material decomposition process. A novel DE virtual monochromatic image processing is performed from a density projection image, and Figures 7 and 8 show the image generated by each reconstruction algorithm.

Figure 6. DE material decomposition straight projection images. The DE material decomposition projections for CaCO3, epoxy, and PMMA were window level = 0.59 and window width = 0.26, window level = 0.69 and window width = 0.33,

Figure 7. Comparisons among the polychromatic (P) and virtual monochromatic (VM) images acquired by using the FBP

adjusted to an internal signal (ROI diameter; eight pixels).

80 Medical Imaging and Image-Guided Interventions

and window level = 0.21 and window width = 0.24, respectively.

reconstruction algorithm (window level = 0.05, window width = 0.11).

8. Results

Figure 8. Comparisons among the polychromatic (P) and virtual monochromatic (VM) images with each IR algorithm (P MLEM: Window level = 0.32, window width = 0.17; VM MLEM: Window level = 0.25, window width = 0.12; P&VM SART: Window level = 0.22, window width = 0.37; P&VM SART-TV: Window level = 0.24, window width = 0.34).

Figure 9. Comparisons of the CNR of the in-focus plane images obtained by using each reconstruction algorithm with polychromatic and virtual monochromatic image processing (CaCO3; 15 mm ϕ, 175 mg/ml).

on the desired final images and DT imaging conditions, of this novel DE virtual monochromatic

State-Of-The-Art X-Ray Digital Tomosynthesis Imaging http://dx.doi.org/10.5772/intechopen.81667 83

We wish to thank Mr. Kazuaki Suwa and Yuuki Watanabe at Department of Radiology

This article does not contain any studies with human participants or animals performed by

[1] Ziedses des Plante BG. Eine neue methode zur differenzierung in der roentgenographie

[2] Grant DG. Tomosynthesis. A three-dimensional radiographic imaging technique. IEEE

Dokkyo Medical University Koshigaya Hospital for support on experiment.

image-processing algorithm may be beneficial to users.

The authors declare that they have no conflict of interest.

Acknowledgements

Conflict of interest

Ethical approval

any of the authors.

Informed consent

Author details

Tsutomu Gomi

References

This articles does not contain patient data.

Kitasato University, Sagamihara, Japan

Address all correspondence to: gomi@kitasato-u.ac.jp

(planigraphie). Acta Radiologica. 1932;13:182-192

Transactions on Biomedical Engineering. 1972;19:20-28

Figure 10. Comparisons of the CNR of in-focus plane images obtained by using each reconstruction algorithm with polychromatic and virtual monochromatic image processing (CaCO3; 15 mm ϕ, 100 mg/ml).

In the novel DE virtual monochromatic image processing performed according to Eq. 17, an image with decreased noise can be obtained as the photon energy was increased. In the conventional polychromatic image, noise is reduced in the high-voltage image. With regard to the contrast extraction capability of high-density objects, the novel DE virtual monochromatic images showed high CNRs. In particular, the SART-TV algorithm provided highcontrast extraction capability (Figure 9). Along with the decrease in the concentration of the object, the contrast extraction ability was almost the same for both monochromatic and virtual monochromatic imaging (Figure 10).
