The qualitative and quantitative assessment of gas flow has become increasingly relevant in the use of everyday systems. The micro flow sensor, developed by Innovative Sensor Technology AG （Switzerland）, is by princ...The qualitative and quantitative assessment of gas flow has become increasingly relevant in the use of everyday systems. The micro flow sensor, developed by Innovative Sensor Technology AG （Switzerland）, is by principle a calorimetric flow sensor produced as a micro system on a glass substrate by means of photolithography and glass etching technology. These structures are arranged as a platinum micro heater and sensor in a Wheatstone bridge. The subsequent etching process produces an exposed area of polyimide membrane that is only a few microns thick and includes the resistive sensor structure as the active area. In addition, the RTD （resistance temperature detector） technology included on the sensor allows for the implementation of a variety of electronic biasing and signal processing modes. Since the sensor can be powered and the bridge can be measured in both CTA （constant temperature anemometer） and calorimetric mode, new possibilities are presented for both low and high flow rates with regard to temperature compensation, self-calibration and self-monitoring.展开更多
目的:评估双源CT(dual-source CT,DSCT)双球管模式超低管电压(70 k V)下肢CTA检查的图像质量、辐射剂量。方法:收集90例腹主动脉及下肢动脉CTA的患者随机分为3组:A组:70 k V管电压,双球管模式,SAFIRE-3;B组:100 k V管电压,单球管模式,...目的:评估双源CT(dual-source CT,DSCT)双球管模式超低管电压(70 k V)下肢CTA检查的图像质量、辐射剂量。方法:收集90例腹主动脉及下肢动脉CTA的患者随机分为3组:A组:70 k V管电压,双球管模式,SAFIRE-3;B组:100 k V管电压,单球管模式,滤波反投影(filtered back projection,FBP);C组:70 k V管电压,单球管模式,SAFIRE-3。测量腹主动脉、髂总动脉、股动脉、腘动脉的4个血管感兴趣区(region of interest,ROI)的CT值,信噪比(signal to noise ratio,SNR)和对比噪声比(contrast to noiseratio,CNR)及图像质量主观评分,并比较3组间辐射剂量。结果:①双球管70 k V组(A组)和单源70 k V组(C组)腹主动脉、髂总动脉、股动脉的3个血管ROI的CT值高于单源100 k V组(B组),双球管70 k V组SNR及CNR明显高于B、C组,差异有统计学意义(P<0.05)。②远端细小分支的显示双球管70 k V组(A组)明显优于B、C组,而B、C组间差异无统计学意义(P>0.05)。③3组CT剂量指数(CT dose index volume,CTDIvol)、剂量长度乘积(dose length product,DLP)差异均有统计学意义(P<0.05),B>A>C,双球管70 k V组(A组)较单源70 k V组(C组)辐射剂量升高约24%,但较单源100 k V组(B组)辐射剂量降低约18%。结论:大螺距双球管模超低管电压70 k V联合迭代重建技术下肢CTA检查,可降低辐射剂量,明显提高图像质量,并有利于远端细小血管分支的显示。展开更多
探讨双源CT低管电压联合迭代重建在非心电门控大螺距(Flash)扫描主动脉CTA的图像质量及可行性。将60例行主动脉CTA检查的患者随机分成A、B两组,A组采用100k V Flash扫描,B组采用80k V Flash扫描,分别进行FBP重建(A_1、B_1组)和迭代重建(...探讨双源CT低管电压联合迭代重建在非心电门控大螺距(Flash)扫描主动脉CTA的图像质量及可行性。将60例行主动脉CTA检查的患者随机分成A、B两组,A组采用100k V Flash扫描,B组采用80k V Flash扫描,分别进行FBP重建(A_1、B_1组)和迭代重建(A_2、B_2组);对4组主动脉图像质量进行主观及客观评价。分析A、B组的有效辐射剂量,A_1、A_2组,B_1、B_2组及A_1、B_2组的图像质量是否有统计学差异。A_1、A_2和B_1、B_2组不同测量层面的CT值均无统计学差异,噪声、SNR及CNR均有显著统计学差异(P<0.01);A_1、B_2组不同测量层面的CT值和噪声均有显著统计学差异(P<0.01),SNR和CNR均无统计学差异(P>0.05);A_1、A_2组及A_1、B_2组图像质量评分无统计学差异(P=0.557/P=0.643),B_1、B_2组图像质量评分有统计学差异(P=0.030)。双源CT Flash扫描低管电压联合迭代重建主动脉CTA成像,能在获得满足诊断要求图像质量的同时显著降低辐射剂量。展开更多
文摘The qualitative and quantitative assessment of gas flow has become increasingly relevant in the use of everyday systems. The micro flow sensor, developed by Innovative Sensor Technology AG （Switzerland）, is by principle a calorimetric flow sensor produced as a micro system on a glass substrate by means of photolithography and glass etching technology. These structures are arranged as a platinum micro heater and sensor in a Wheatstone bridge. The subsequent etching process produces an exposed area of polyimide membrane that is only a few microns thick and includes the resistive sensor structure as the active area. In addition, the RTD （resistance temperature detector） technology included on the sensor allows for the implementation of a variety of electronic biasing and signal processing modes. Since the sensor can be powered and the bridge can be measured in both CTA （constant temperature anemometer） and calorimetric mode, new possibilities are presented for both low and high flow rates with regard to temperature compensation, self-calibration and self-monitoring.
文摘目的:评估双源CT(dual-source CT,DSCT)双球管模式超低管电压(70 k V)下肢CTA检查的图像质量、辐射剂量。方法:收集90例腹主动脉及下肢动脉CTA的患者随机分为3组:A组:70 k V管电压,双球管模式,SAFIRE-3;B组:100 k V管电压,单球管模式,滤波反投影(filtered back projection,FBP);C组:70 k V管电压,单球管模式,SAFIRE-3。测量腹主动脉、髂总动脉、股动脉、腘动脉的4个血管感兴趣区(region of interest,ROI)的CT值,信噪比(signal to noise ratio,SNR)和对比噪声比(contrast to noiseratio,CNR)及图像质量主观评分,并比较3组间辐射剂量。结果:①双球管70 k V组(A组)和单源70 k V组(C组)腹主动脉、髂总动脉、股动脉的3个血管ROI的CT值高于单源100 k V组(B组),双球管70 k V组SNR及CNR明显高于B、C组,差异有统计学意义(P<0.05)。②远端细小分支的显示双球管70 k V组(A组)明显优于B、C组,而B、C组间差异无统计学意义(P>0.05)。③3组CT剂量指数(CT dose index volume,CTDIvol)、剂量长度乘积(dose length product,DLP)差异均有统计学意义(P<0.05),B>A>C,双球管70 k V组(A组)较单源70 k V组(C组)辐射剂量升高约24%,但较单源100 k V组(B组)辐射剂量降低约18%。结论:大螺距双球管模超低管电压70 k V联合迭代重建技术下肢CTA检查,可降低辐射剂量,明显提高图像质量,并有利于远端细小血管分支的显示。
文摘探讨双源CT低管电压联合迭代重建在非心电门控大螺距(Flash)扫描主动脉CTA的图像质量及可行性。将60例行主动脉CTA检查的患者随机分成A、B两组,A组采用100k V Flash扫描,B组采用80k V Flash扫描,分别进行FBP重建(A_1、B_1组)和迭代重建(A_2、B_2组);对4组主动脉图像质量进行主观及客观评价。分析A、B组的有效辐射剂量,A_1、A_2组,B_1、B_2组及A_1、B_2组的图像质量是否有统计学差异。A_1、A_2和B_1、B_2组不同测量层面的CT值均无统计学差异,噪声、SNR及CNR均有显著统计学差异(P<0.01);A_1、B_2组不同测量层面的CT值和噪声均有显著统计学差异(P<0.01),SNR和CNR均无统计学差异(P>0.05);A_1、A_2组及A_1、B_2组图像质量评分无统计学差异(P=0.557/P=0.643),B_1、B_2组图像质量评分有统计学差异(P=0.030)。双源CT Flash扫描低管电压联合迭代重建主动脉CTA成像,能在获得满足诊断要求图像质量的同时显著降低辐射剂量。
