An x-ray scintillator screen with a special structure, functioning as detector and analyser grating, was proposed for collecting the interferogram of differential phase contrast imaging without absorption grating and ...An x-ray scintillator screen with a special structure, functioning as detector and analyser grating, was proposed for collecting the interferogram of differential phase contrast imaging without absorption grating and difficulty of fabrication by a state of the art technique. On the basis of phase grating diffraction, a detecting model of the scintillator screen was built for analysing the phase and absorption information of objects. According to the analysis, a new method of phase retrievals based on two-images and the optimal structure of screen were presented.展开更多
目的探讨DW-MRI(diffusion-weighted magnetic resonance imaging,DW-MRI)作为乳腺X线摄影(mammography,MMG)筛查乳腺癌的补充方式在致密性乳腺中的诊断效能,并对比分析与动态增强磁共振成像(dynamic contrast-enhanced magnetic resona...目的探讨DW-MRI(diffusion-weighted magnetic resonance imaging,DW-MRI)作为乳腺X线摄影(mammography,MMG)筛查乳腺癌的补充方式在致密性乳腺中的诊断效能,并对比分析与动态增强磁共振成像(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)诊断价值的差异。方法回顾性分析病理确诊的82例乳腺癌患者及41例健康或病理证实为良性病变的阴性病例作为模拟筛查人群,分析其MMG及DWI、MMG/DWI、DCE-MRI影像学资料,比较4种检查技术对乳腺疾病诊断的敏感性和特异性。结果MMG、DWI、MMG/DWI及DCE-MRI诊断的敏感性分别为52.44%、76.83%、85.37%、93.90%;特异性分别为51.22%、65.85%、78.05%、85.36%。MMG与DWI联合检查的敏感性及特异性显著高于MMG单独检查(P<0.01),但仍低于DCE-MRI(P>0.05)。MMG/DWI的受试者工作特性(receiver operating characteristic,ROC)曲线下面积(AUC)(AUC 0.817)虽然低于DCE-MRI(AUC 0.896),但与单独的MMG(AUC 0.518)相比,MMG和DWI-MRI的组合具有更高的敏感度(85.37%)。结论在乳腺组织致密的女性中,DWI和MMG相结合可明显提高诊断的敏感性和特异性。DW-MRI可作为一种快速辅助筛查乳腺癌的工具。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 60232090 and 10774102)the Science & Technology Project from Shenzhen Government of China (Grant Nos. 2008340 and 200717)
文摘An x-ray scintillator screen with a special structure, functioning as detector and analyser grating, was proposed for collecting the interferogram of differential phase contrast imaging without absorption grating and difficulty of fabrication by a state of the art technique. On the basis of phase grating diffraction, a detecting model of the scintillator screen was built for analysing the phase and absorption information of objects. According to the analysis, a new method of phase retrievals based on two-images and the optimal structure of screen were presented.
