光电子技术
光電子技術
광전자기술
OPTOELECTRONIC TECHNOLOGY
2009年
4期
244-250
,共7页
X射线同轴相衬成像%成像质量%参数优化%一维高斯分布
X射線同軸相襯成像%成像質量%參數優化%一維高斯分佈
X사선동축상츤성상%성상질량%삼수우화%일유고사분포
X-ray in-line phase contrast imaging%imaging quality%optimization of parameters%one dimensional Gaussian distribution
采用图像衬度、信噪比、分辨率和探测器抽样数作为X射线同轴相衬成像质量的综合评价标准,针对具有广泛应用意义的一维高斯型分布特征的物体,建立了最大化衬度优化和信噪比优化两种参数优化方法的优化流程.通过数值模拟的方式分别对亚微焦点源、激光驱动微焦点源及同步辐射源3种不同X射线源下的成像系统相关参数进行了优化.结果表明,两种优化方法各具优势,可根据不同的相衬成像需求选择相应的优化方法.同步辐射源同轴相衬成像系统采用信噪比优化方法较为合适,而亚微焦点源和激光驱动微焦点源则需根据不同的需求来选择优化方法,必要时还可对优化方法进行一定的修正.研究为不同条件下有着不同要求的优质X射线同轴相衬成像实验提供了保证.
採用圖像襯度、信譟比、分辨率和探測器抽樣數作為X射線同軸相襯成像質量的綜閤評價標準,針對具有廣汎應用意義的一維高斯型分佈特徵的物體,建立瞭最大化襯度優化和信譟比優化兩種參數優化方法的優化流程.通過數值模擬的方式分彆對亞微焦點源、激光驅動微焦點源及同步輻射源3種不同X射線源下的成像繫統相關參數進行瞭優化.結果錶明,兩種優化方法各具優勢,可根據不同的相襯成像需求選擇相應的優化方法.同步輻射源同軸相襯成像繫統採用信譟比優化方法較為閤適,而亞微焦點源和激光驅動微焦點源則需根據不同的需求來選擇優化方法,必要時還可對優化方法進行一定的脩正.研究為不同條件下有著不同要求的優質X射線同軸相襯成像實驗提供瞭保證.
채용도상츤도、신조비、분변솔화탐측기추양수작위X사선동축상츤성상질량적종합평개표준,침대구유엄범응용의의적일유고사형분포특정적물체,건립료최대화츤도우화화신조비우화량충삼수우화방법적우화류정.통과수치모의적방식분별대아미초점원、격광구동미초점원급동보복사원3충불동X사선원하적성상계통상관삼수진행료우화.결과표명,량충우화방법각구우세,가근거불동적상츤성상수구선택상응적우화방법.동보복사원동축상츤성상계통채용신조비우화방법교위합괄,이아미초점원화격광구동미초점원칙수근거불동적수구래선택우화방법,필요시환가대우화방법진행일정적수정.연구위불동조건하유착불동요구적우질X사선동축상츤성상실험제공료보증.
Contrast, signal-to-noise ratio (SNR), resolution and sampling are used as an integrated evaluation standard for the imaging quality of the X-ray in-line phase contrast imaging system. Two kinds of parameters optimized flows for Maximum contrast and SNR optimized methods are erected for the object of one dimensional Gaussian distribution which is widely applied to many fields. The correlative parameters of the imaging systems under the radiation of sub-micrometer focus X-ray source, laser-based micrometer focus X-ray source and synchrotron radiation X-ray source are optimized by the means of numerical simulation. The outcome shows that each optimized method has its advantages and disadvantages. The optimized method can be chosen by different requirements of the in-line phase contrast imaging. The SNR optimized method is available to the synchrotron radiation X-ray source, while the optimized methods of the sub-micrometer focus X-ray source and laser-based micrometer focus X-ray source should be chosen according to different requirements and may be corrected if necessary. The research can provide sustain for high quality X-ray in-line phase contrast imaging of different conditions and requirements.