Development of X-ray optics for medical imaging systems using synchrotron monochromatic X-ray

在PF-AR上利用偏转磁铁产生的同步辐射进行了开发适用于使用同步辐射单色X射线的二维静脉冠状动脉造影系统的单色器的初步实验，KEK.研制该成像系统的目的是建立一种比常规动脉内冠状动脉造影安全、简便的诊断缺血性心脏病的方法。在33 keV（高于碘的K边能量）和52 keV（高于钆的K边能量）下，由表面研磨1200个SiC的硅单色器产生的X射线辐射比由蚀刻的硅单色器产生的辐射增加约5至10倍。这种方法可以为我们提供一种简单的方法来增加光子通量密度。在筑波大学和材料结构科学研究所的合作下，在PF-AR的二维静脉内冠状动脉血管造影系统的临床应用中使用了表面研磨了1200个SiC的非对称切割Si（311）晶体。单色仪的光子通量密度为10^<10>光子/平方毫米/秒，足以用于临床检查。多层单色器反射X射线的积分强度比叠层单色器提高约5倍，但辐射场强度不均匀，进一步的研究将需要开发一种多层单色器，三维静脉冠状动脉造影系统。这些单色器将是有用的，为未来的紧凑型同步辐射源，专门用于临床应用。

Preliminary experiments on developing a suitable monochromator for the two-dimensional intravenous coronary angiography system using synchrotron monochromatic X-ray were done using synchrotron radiation produced by a bending magnet at the PF-AR, KEK.The purpose of developing the imaging system is to establish a safe and simple diagnostic method for the ischemic heart disease than the conventional intra-arterial coronary angiography.The integral intensity of reflected X-rays by a silicon monochromator which surface was lapped by the number of 1200 SiC, was increased about 5 to 10 times than that by a etched silicon monochromator at 33 keV (above the K-edge energy of Iodine) and 52 keV (above the K-edge energy of Gadolinium). This method can provide us a easy way to increase the photon flux density. An asymmetrical cut Si(311) crystal which surface was lapped by the number of 1200 SiC was used for clinical applications of the two-dimensional intravenous coronary angiography system at PF-AR under the collaboration between The University of Tsukuba and Institute of Materials Structure Science. The photon flux density available from the monochromator was 10^<10> photons/mm^2/sec, which was enough for clinical examinations. The integral intensity of reflected X-rays by a multi-layer monochromator was increased about 5 times than that by a lapped silicon monochromator, however, the intensity of the radiation field was not uniform, and the further investigations will be need to develop a multi-layer monochromator for the two-dimensional intravenous coronary angiography system.These monochromators will be useful for the future compact synchrotron radiation source dedicated to clinical applications.