In this Letter,we propose a simple structure of an orthogonal type double Michelson interferometer.The orthogonal detection method overcomes the problems of uneven ranging sensitivity and the inability of traditional ...In this Letter,we propose a simple structure of an orthogonal type double Michelson interferometer.The orthogonal detection method overcomes the problems of uneven ranging sensitivity and the inability of traditional interferometers to determine the displacement direction.The displacement measurement principle and signal processing method of the orthogonal double interferometer are studied.Unlike the arctangent algorithm,the displacement analysis uses the arc cosine algorithm,avoiding any pole limit in the distance analysis process.The minimum step size of the final experimental displacement system is 5 nm,which exhibits good repeatability,and the average error is less than 0.12 nm.展开更多
目的探讨宝石能谱CT(GE Discovery CT750,HDCT)单能量成像在提高甲状腺结节图像质量方面的临床应用价值。方法搜集临床拟诊甲状腺结节受检者20例,应用能谱(GSI)模式平扫获得最佳CNR图像,并将代表120 k Vp混合能量等效噪声的70 ke V图像(...目的探讨宝石能谱CT(GE Discovery CT750,HDCT)单能量成像在提高甲状腺结节图像质量方面的临床应用价值。方法搜集临床拟诊甲状腺结节受检者20例,应用能谱(GSI)模式平扫获得最佳CNR图像,并将代表120 k Vp混合能量等效噪声的70 ke V图像(STD)和最佳CNR单能量图像导入GE AW 4.6工作站,由2名有经验的放射科医师在4分量表上对每位受检者两组图像进行噪声和结节内外边界清晰度评分(1分最差;4分最好)。使用Wilcoxon符号秩检验比较两组图像主观评分。结果两位医生对图像噪声与细小结构显示评分均为STD图像低于最佳CNR组图像,差异有统计学意义(Z=-3.542和-3.704,P<0.05);对甲状腺结节内外边界清晰度评分也是STD组图像低于最佳CNR组图像(Z=-3.441和-3.153,P<0.05),差异有统计学意义。结论 GSI最佳单能量能可明显改善由于颈部噪声而影响的甲状腺结节图像质量并能更清晰显示结节边界,可提高甲状腺结节小病变的检出率并对结节性质鉴别诊断具有一定的临床价值。展开更多
基金supported in part by the National Natural Science Foundation of China(No.62005194).
文摘In this Letter,we propose a simple structure of an orthogonal type double Michelson interferometer.The orthogonal detection method overcomes the problems of uneven ranging sensitivity and the inability of traditional interferometers to determine the displacement direction.The displacement measurement principle and signal processing method of the orthogonal double interferometer are studied.Unlike the arctangent algorithm,the displacement analysis uses the arc cosine algorithm,avoiding any pole limit in the distance analysis process.The minimum step size of the final experimental displacement system is 5 nm,which exhibits good repeatability,and the average error is less than 0.12 nm.
文摘目的探讨宝石能谱CT(GE Discovery CT750,HDCT)单能量成像在提高甲状腺结节图像质量方面的临床应用价值。方法搜集临床拟诊甲状腺结节受检者20例,应用能谱(GSI)模式平扫获得最佳CNR图像,并将代表120 k Vp混合能量等效噪声的70 ke V图像(STD)和最佳CNR单能量图像导入GE AW 4.6工作站,由2名有经验的放射科医师在4分量表上对每位受检者两组图像进行噪声和结节内外边界清晰度评分(1分最差;4分最好)。使用Wilcoxon符号秩检验比较两组图像主观评分。结果两位医生对图像噪声与细小结构显示评分均为STD图像低于最佳CNR组图像,差异有统计学意义(Z=-3.542和-3.704,P<0.05);对甲状腺结节内外边界清晰度评分也是STD组图像低于最佳CNR组图像(Z=-3.441和-3.153,P<0.05),差异有统计学意义。结论 GSI最佳单能量能可明显改善由于颈部噪声而影响的甲状腺结节图像质量并能更清晰显示结节边界,可提高甲状腺结节小病变的检出率并对结节性质鉴别诊断具有一定的临床价值。
