【摘要】 主要对微焦点源X射线同轴相衬成像系统的系统参数进行了设计与讨论,并对结果进行了实验验证.根据实际选取X射线能量以及物体的折射率改变量和吸收因子来确定物体传输函数,从物体到探测面的距离、物体边缘渐变宽度等因素对图像可见度的影响进行分析,提出了改进分辨率方法并通过数值模拟得到验证.最后,在实验中对普通三角板进行相衬成像,并与其吸收衬度成像进行对比.实验结果表明,利用数值模拟的方法可以指导微焦点源相衬成像参数设计,同时验证了该实验仪器的相衬能力.更多还原

【Abstract】 This paper introduces the design,analysis and experimental verification of focal spot X-ray in-line imaging system.First of all,the object transmission function is fixed by the refractive index decrement and the absorption index of tissue according to the previously selected energy.After the factors being analyzed,such as the distance between the object and detector,and the object edge width,which can affect imaging quality,methods presented to improve image resolution are validated.In the experiment,plastic set square is irradiated with X-ray phase-contrast technique.The result is then compared with that using traditional X-ray imaging technique.The experimental results exhibit considerable consistency with former numerical simulation,which proves that the particular method can be used to determine the parameters of imaging system.更多还原