Three-Dimensional Monochromatic X-ray CT
Grant-in-Aid for Developmental Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||University of Tsukuba|
SAITO Tsuneo Institute of Information Sciences and Electronics University of Tsukuba, Professor, 電子・情報工学系, 教授 (70005312)
TAKEDA Tohru Institute of Clinical Medicine University of Tsukuba, Assistant Professor, 臨床医学系, 講師 (10197311)
KUDO Hiroyuki Institute of Information Sciences and Electronics University of Tsukuba, Associa, 電子・情報工学系, 助教授 (60221933)
|Project Period (FY)
1994 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥12,700,000 (Direct Cost : ¥12,700,000)
Fiscal Year 1995 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1994 : ¥11,000,000 (Direct Cost : ¥11,000,000)
|Keywords||3-D computer tomography / image reconstruction algorithm / energy subtraction / synchrotron radiation / fluorescent X-rays / 3-D imaging / コンピュータトモグラフィ(CT) / 放射光 / 画像再構成アルゴリズム|
The development of three-dimensional (3-D) monochromatic X-ray CT has been investigated as a new generation CT.Direct reconstruction in 3-D from two-dimensional (2-D) projection data can be achieved by cone-beam CT.
The following findings could be obtained through the investigation as ;
1. Based on the completeness condition for mathematically exact reconstruction, an orthogonal circle-and-line orbit has been adopted as the most promissing scanning method of X-ray source in 3-D CT system configuration.
2. The mathematically exact 3-D CT image reconstruction algorithm has been derived from the inversion formula of 3-D Radon transform in the practically implementable form.
3. Computer simulation studies have demonstrated the validity of the proposed scanning method and the derived reconstruction algorithm.
4. A proto type experimental system of 3-D monochromatic X-ray CT using fluorescent X-rays generated by synchrotron radiation was constructed in National Laboratory for High Energy Physics
in Tsukuba. The fluorescent X-rays generated by irradiating the target material with a white X-ray produce a cone-beam geometry with large beam area and spatially uniform intensity, and its energy is tunable by changing the target materials.
5. The oject is mounted on the computer controlled device which simulates the scanning of circle-and-line orbit, and 2-D projection data is acquired by the image intensifier. The complete reconstruction of 3-D structure of object could be achieved in this experimental system.
6. Using the desirable characteristic of tunable X-ray source, 3-D image of specific materials (for example contrast materials) is reconstructed by taking subtraction between images above and below K-absorption edge of materials. The 3-D structure of object can be visualized by the visualization software.
7. The most serious problem in the cone-beam data collection scheme is the scattering of photons in tissue which degrades the image quality. If we can resolve this problem, 3-D image with absolute CT value of tissue is available because of the absence of beam hardening. Less
Research Output (22results)