| Project/Area Number |
14580844
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Japan Synchrotron Radiation Research Institute |
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Principal Investigator |
UMETANI Keiji Japan Synchrotron Radiation Research Institute, Life and Environmental Science Div., Senior Scientist, 利用研究促進部門II・医学チーム, 主幹研究員 (50344396)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASAKI Katsuhito Japan Synchrotron Radiation Research Institute, Life and Environmental Science Div., Associate Chief Scientist, 利用研究促進部門II・医学チーム, チームリーダー・副主席研究員 (50210381)
YAGI Naoto Japan Synchrotron Radiation Research Institute, Life and Environmental Science Div., Chief Scientist, 利用研究促進部門II・生物-医学グループ, グループリーダー・主席研究員 (80133940)
SUGIMURA Kazuro Kobe University, School of Medicine, Professor, 医学部, 教授 (00136384)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Microangiography / Coronary artery / Contrast agent / Synchrotron radiation / Monochromatic X-ray / X-ray SATICON / Vasoactive agent / Vasoconstriction and vasodilatation / 血管拡張反応 / 血管収縮反応 / 心疾患 |
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| Research Abstract |
A microangiography system with spatial resolution in the micrometer range was developed to depict coronary vascular response in a rat heart under Langendorff perfusion using a high-speed imaging system and a third generation synchrotron radiation source at SPring-8. The imaging system was composed of an X-ray direct-conversion type detector incorporating an X-ray SATICON pickup tube and a high-speed X-ray shutter using a galvanometer based scanner. Microangiographic images were obtained without image blur and stored in a digital frame memory system with a 1024_×1024-pixel, 10-bit format.
An X-ray imaging system needs to have high shutter speed (short exposure time) to make sharp and blur-free images of objects. For high-speed imaging, we developed an X-ray shutter system using a moving-coil galvanometer-based optical scanner. An optical scanner is a high-accuracy mirror positioning motor for laser optics. After an optical mirror was removed from the galvanometer-based scanner, a rotatin
… More
g X-ray chopper was attached to a center shaft of the scanner. Twin tantalum blades on each side of the chopper move in a seesaw-like manner. By about 9° rotation of the chopper, the shutter opens or closes a route for the X-ray beam.
The shutter system was located between the monochromator and the object. Since thickness of each tantalum blade is 3 mm, the shutter can be used at X-ray energies of 30-50 keV. The chopper rotates to synchronize timing with synchronous signals of a video camera. The shortest shutter open time was 2 ms. X-ray exposure time is thereby proportional to the shutter open time and each X-ray image is detected in 2 ms by the X-ray direct-conversion type detector.
Visualization of vasoconstriction and vasodilatation of coronary arteries with vasoactive agents is a useful research tool for evaluation of coronary vascular reserve. In imaging experiments, the isolated rat heart was mounted on a steel cannula and per fused with oxygenated per fusion fluid. After iodine contrast agent injection into the ascending aorta, small cardiac blood vessels of less than 50 μm diameter were visualized at heart rates of 300-400 per minute under Langendorff per fusion, and vasodilatation in small arteries was visualized in response to vasoactive agents. This synchrotron radiation high-speed imaging system is a useful tool for depicting large and small coronary arteries in fast-moving hearts and for quantifying actual change in their diameter by vasoactive agents. Less
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