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The technique of computed tomography (CT) has been used in various fields, such as medical, non-destructive testing (NDT), baggage checking, etc. A 3D-CT system based on the portable synchrotron “MIRRORCLE”-series will be a novel instrument for these fields. The hard x-rays generated from the “MIRRORCLE” have a wide energy spectrum. Light and thin materials create absorption and refraction contrast in x-ray images by the lower energy component (< 60 keV), and heavy and thick materials create absorption contrast by the higher energy component. In addition, images with higher resolutions can be obtained using “MIRRORCLE” with a small source size of micron order. Thus, high resolution 3D-CT images of specimens containing both light and heavy materials can be obtained using “MIRRORCLE” and a 2D-detector with a wide dynamic range. In this paper, the development and output of a 3D-CT system using the “MIRRORCLE-6X” and a flat panel detector are reported. A 3D image of a piece of concrete was obtained. The detector was a flat panel detector (VARIAN, PAXSCAN2520) with 254 μm pixel size. The object and the detector were set at 50 cm and 250 cm respectively from the x-ray source, so that the magnification was 5x. The x-ray source was a 50 μm Pt rod. The rotation stage and the detector were remote-controlled using a computer, which was originally created using LabView and Visual Basic software. The exposure time was about 20 minutes. The reconstruction calculation was based on the Feldkamp algorithm, and the pixel size was 50 μm. We could observe sub-mm holes and density differences in the object. Thus, the “MIRRORCLE-CV” with 1MeV electron energy, which has same x-ray generation principles, will be an excellent x-ray source for medical diagnostics and NDT. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The portable synchrotron MERRORCLE-6X is a novel x-ray source suitable for hard x-ray imaging. Highly brilliant x-rays are generated by MIRRORCLE-6X in the shape of cone from a source with micron size. We obtained images with high magnification and high resolution by these x-rays, and found that they can be utilized for medical imaging. Recently, we started to perform ideal 3-dimentional computed tomography (3D-CT) based on the Feldkamp algorithm, which is the most popular reconstruction algorithm for a cone beam CT, using a flat panel detector. Therefore, we developed a magnified 3D-CT system of high quality using MIRRORCLE-6X. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Monochromatic x-ray CT at two different energies provides information about electron density without ambiguity due to the beam hardening effect. This information makes the treatment planning for heavy-ion radiotherapy more precise. We have started a feasibility study on the dual-energy x-ray CT by using synchrotron radiation. We developed a linear scanning CT system in order to evaluate what precision in the measurement was achieved. The experiments were carried out using monochromatic x-rays of 40, 70 and 80 key. Comparison of measured electron densities with the theoretical values proved that these values were in agreement in 0.9 % on average. We have developed a 2D-CT system with a two-dimensional scintillator array to take images in a short time. At present, it has been proved that the electron density is measured in the precision of about 1% with the 2D-CT system. Effective atomic numbers are obtained as well from the dual-energy x-ray CT. The CT images are reconstructed based on each of the electron density and the effective atomic number. They present different features of an object, and the contrasts in the images differ from that in a conventional CT image. The feature of the images may help distinguish more clearly tissues or organs with aid of different contrast from the conventional CT images. [ABSTRACT FROM AUTHOR]