X-ray imaging systems capable of evaluating the lesion of interest for biomedical and industrial samples using the capability of synchrotron radiation
分離型干渉計を用いた位相コントラストＸ線CTシステム (BL-14C)
Synchrotron radiation provides a new source of X-rays for imaging to visualize a sample, which is difficult to visualize using the conventional X-ray sources. Because synchrotron radiation is the nearly parallel and intense beam, one can get the nearly parallel monochromatic X-rays, which can increase the contrast and the resolution of X-ray images.
- Absorption-contrast imaging:
Micro-angiography
Conventional angiographic system cannot identify the peripheral artery at less than 200 microns in diameter. However, applying a new angiographic system using monochromatic synchrotron X-rays with a high-resolution two-dimensional detector system, it is possible to identify the smaller arteries up to 50 microns so far.
- Phase-contrast imaging :
Phase-contrast X-ray imaging is capable of providing improved information from weakly absorbing features in a sample. When X-rays propagate through a sample, the wave front of the X-rays is deformed due to the phase-shifts caused by the object. X-ray phase-contrast imaging detects these phase-shifts for observing the inner structures of various objects non-destructively. Because the sensitivity of the X-ray phase-contrast imaging is much higher than that of the absorption-contrast imaging, worldwide efforts have been made for R&D of this innovative technique. At the Photon Factory, X-ray interferometry, X-ray diffraction enhanced imaging (DEI), X-ray dark-field imaging (DFI), X-ray coherent diffraction microscopy (XCD), X-ray Talbot interferometry, X-ray Talbot-Lau interferometry and so on, have been pursued intensively.
- X-ray phase-contrast CT using an X-ray interferometer:
X-ray phase-contrast CT using an X-ray interferometer was, for the first time, developed at BL-14B in 1996. At that time, the view field was about 15mm (V) x 10 mm (H) in size due to the limited size of the beam and interferometer. To enlarge the view-field, the activity was moved from BL-14B to BL-14C and large-size X-ray interferometers were produced. Figure 1 shows an X-ray imaging system with a two-crystal interferometer. The size of the view field is more than 50mm (V) x 50mm (H) for 35 keV X-rays. One can get a vertically polarized synchrotron radiation beam at BL-14, therefor it is suitable to develop a large-size X-ray interferometer with large-size Laue-type silicon crystals. The cross-section of phase-shift of light elements in the hard X-ray region is about 1000 times larger than that of absorption, therefor this imaging method provides a way to perform detailed evaluation of samples such as biological soft tissues and organic materials.
Beam Lines
BL-14B, BL-14C, AR-NE7A
