核技术
覈技術
핵기술
Nuclear Techniques
2015年
9期
090101-1-090101-7
,共1页
鲍园%王研%朱佩平%吴自玉
鮑園%王研%硃珮平%吳自玉
포완%왕연%주패평%오자옥
衍射增强成像%噪声分析%余弦曲线拟合%蒙特卡罗仿真
衍射增彊成像%譟聲分析%餘絃麯線擬閤%矇特卡囉倣真
연사증강성상%조성분석%여현곡선의합%몽특잡라방진
Diffraction enhanced imaging%Noise analysis%Cosine fitting radiography%Monte Carlo simulations
衍射增强成像是一种功能强大的相位衬度成像技术,其信息分离研究一直都是研究热点。提出了一种简便的信息分离方法——余弦曲线拟合法(Cosine Fitting Radiography, CFR),该方法具有简便、样品所受辐射剂量低等优点。利用同步辐射实验和蒙特卡罗仿真方法,从角度信号成像模型出发解释了此方法,同时从噪声传递角度分析了该方法的性能和给出定量的评价指标,建立了衍射增强成像和光栅微分干涉成像之间更直观的联系。对理解衍射增强成像系统的噪声行为和提高信噪比具有一定的参考意义。
衍射增彊成像是一種功能彊大的相位襯度成像技術,其信息分離研究一直都是研究熱點。提齣瞭一種簡便的信息分離方法——餘絃麯線擬閤法(Cosine Fitting Radiography, CFR),該方法具有簡便、樣品所受輻射劑量低等優點。利用同步輻射實驗和矇特卡囉倣真方法,從角度信號成像模型齣髮解釋瞭此方法,同時從譟聲傳遞角度分析瞭該方法的性能和給齣定量的評價指標,建立瞭衍射增彊成像和光柵微分榦涉成像之間更直觀的聯繫。對理解衍射增彊成像繫統的譟聲行為和提高信譟比具有一定的參攷意義。
연사증강성상시일충공능강대적상위츤도성상기술,기신식분리연구일직도시연구열점。제출료일충간편적신식분리방법——여현곡선의합법(Cosine Fitting Radiography, CFR),해방법구유간편、양품소수복사제량저등우점。이용동보복사실험화몽특잡라방진방법,종각도신호성상모형출발해석료차방법,동시종조성전체각도분석료해방법적성능화급출정량적평개지표,건립료연사증강성상화광책미분간섭성상지간경직관적련계。대리해연사증강성상계통적조성행위화제고신조비구유일정적삼고의의。
Background: Diffraction enhanced imaging (DEI) is a powerful phase contrast imaging technique. Purpose: This study aims to investigate the noise properties of a new simple cosine fitting radiography for DEI based on the angular signal response imaging prototype. Methods: The rocking curve can be treated as a angular signal response and a simple multi-information retrieval algorithm based on the cosine function fitting. A comprehensive analysis of noise properties in DEI, based on a noise model including the fluctuation of the photon source, and a bias of the analyzer crystal are also given. The validations have been performed with Monte Carlo simulations based on the Geant4 toolkit combined with the refractive process of X-ray and synchrotron radiation experimental data. Results: The cosine fitting radiography (CFR) has been verified by Monte Carlo simulations and experimental data which are in good agreement with each other. The noise penalty is drastically reduced with high photon flux, high visibility and high angular precision. Conclusions: Based on the angular signal response function prototype, we analyze and calculate the noise properties of DEI. In addition, the analytical method can build a strong connection between DEI and grating-based phase contrast imaging (GDPCI) and widely suitable for all kinds of measurement noises in angular signal response imaging prototype. The analysis is useful to understand the noise characteristics of DEI images and improve the signal-noise-ratio of the extracted information for biomedical imaging and material science.