ASTM E1695-1995(2006)e1 计算机层析X射线摄影(CT)系统性能测量的标准试验方法
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【英文标准名称】:StandardTestMethodforMeasurementofComputedTomography(CT)SystemPerformance
【原文标准名称】:计算机层析X射线摄影(CT)系统性能测量的标准试验方法
【标准号】:ASTME1695-1995(2006)e1
【标准状态】:现行
【国别】:
【发布日期】:1995
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E07.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:计算机层析X射线摄影CT;计算机层析X射线;对照物辨别力;对照物的敏感度;几何非锐聚焦;模传送函数;随机噪声;射线层析摄影;射线层析摄影CT系统性能;Y;空间分辨率;图像分析;X射线;测量;试验
【英文主题词】:computedtomography;contrastdiscrimination;contrastsensitivity;CT;geometricalunsharpness;spatialresolution
【摘要】:TwofactorsaffectingthequalityofaCTimagearegeometricalunsharpnessandrandomnoise.GeometricalunsharpnesslimitsthespatialresolutionofaCTsystem,thatis,itsabilitytoimagefinestructuraldetailinanobject.RandomnoiselimitsthecontrastsensitivityofaCTsystem,thatis,itsabilitytodetectthepresenceorabsenceoffeaturesinanobject.Spatialresolutionandcontrastsensitivitymaybemeasuredinvariousways.ASTMspecifiesspatialresolutionbequantifiedintermsofthemodulationtransferfunction(MTF)andcontrastsensitivitybequantifiedintermsofthecontrastdiscriminationfunction(CDF)(seeGuideE1441andPracticeE1570).ThistestmethodallowsthepurchaserortheproviderofCTsystemsorservices,orboth,tomeasureandspecifyspatialresolutionandcontrastsensitivity.1.1ThistestmethodprovidesinstructionfordeterminingthespatialresolutionandcontrastsensitivityinX-rayand-raycomputedtomography(CT)images.ThedeterminationisbasedonexaminationoftheCTimageofauniformdiskofmaterial.Thespatialresolutionmeasurementisderivedfromanimageanalysisofthesharpnessattheedgeofthedisk.Thecontrastsensitivitymeasurementisderivedfromanimageanalysisofthestatisticalnoiseatthecenterofthedisk.1.2Thistestmethodismorequantitativeandlesssusceptibletointerpretationthanalternativeapproachesbecausetherequireddiskiseasytofabricateandtheanalysisisimmunetocuppingartifacts.Thistestmethodmaynotyieldmeaningfulresultsifthediskimageoccupieslessthanasignificantfractionofthefieldofview.1.3Thistestmethodmayalsobeusedtoevaluateotherperformanceparameters.AmongthosecharacteristicsofaCTsystemthataredetectablewiththistestmethodare:themid-frequencyenhancementofthereconstructionkernel,thepresence(orabsence)ofdetectorcrosstalk,theundersamplingofviews,andtheclippingofunphysical(thatis,negative)CTnumbers(seeAirForceTechnicalReportWL-TR-94-4021).Itishighlylikelythatothercharacteristicsaswellcanbedetectedwiththistestmethod.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Inch-poundunitsareprovidedforinformationonly.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:C43
【国际标准分类号】:35_240_80
【页数】:5P.;A4
【正文语种】:
【原文标准名称】:计算机层析X射线摄影(CT)系统性能测量的标准试验方法
【标准号】:ASTME1695-1995(2006)e1
【标准状态】:现行
【国别】:
【发布日期】:1995
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E07.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:计算机层析X射线摄影CT;计算机层析X射线;对照物辨别力;对照物的敏感度;几何非锐聚焦;模传送函数;随机噪声;射线层析摄影;射线层析摄影CT系统性能;Y;空间分辨率;图像分析;X射线;测量;试验
【英文主题词】:computedtomography;contrastdiscrimination;contrastsensitivity;CT;geometricalunsharpness;spatialresolution
【摘要】:TwofactorsaffectingthequalityofaCTimagearegeometricalunsharpnessandrandomnoise.GeometricalunsharpnesslimitsthespatialresolutionofaCTsystem,thatis,itsabilitytoimagefinestructuraldetailinanobject.RandomnoiselimitsthecontrastsensitivityofaCTsystem,thatis,itsabilitytodetectthepresenceorabsenceoffeaturesinanobject.Spatialresolutionandcontrastsensitivitymaybemeasuredinvariousways.ASTMspecifiesspatialresolutionbequantifiedintermsofthemodulationtransferfunction(MTF)andcontrastsensitivitybequantifiedintermsofthecontrastdiscriminationfunction(CDF)(seeGuideE1441andPracticeE1570).ThistestmethodallowsthepurchaserortheproviderofCTsystemsorservices,orboth,tomeasureandspecifyspatialresolutionandcontrastsensitivity.1.1ThistestmethodprovidesinstructionfordeterminingthespatialresolutionandcontrastsensitivityinX-rayand-raycomputedtomography(CT)images.ThedeterminationisbasedonexaminationoftheCTimageofauniformdiskofmaterial.Thespatialresolutionmeasurementisderivedfromanimageanalysisofthesharpnessattheedgeofthedisk.Thecontrastsensitivitymeasurementisderivedfromanimageanalysisofthestatisticalnoiseatthecenterofthedisk.1.2Thistestmethodismorequantitativeandlesssusceptibletointerpretationthanalternativeapproachesbecausetherequireddiskiseasytofabricateandtheanalysisisimmunetocuppingartifacts.Thistestmethodmaynotyieldmeaningfulresultsifthediskimageoccupieslessthanasignificantfractionofthefieldofview.1.3Thistestmethodmayalsobeusedtoevaluateotherperformanceparameters.AmongthosecharacteristicsofaCTsystemthataredetectablewiththistestmethodare:themid-frequencyenhancementofthereconstructionkernel,thepresence(orabsence)ofdetectorcrosstalk,theundersamplingofviews,andtheclippingofunphysical(thatis,negative)CTnumbers(seeAirForceTechnicalReportWL-TR-94-4021).Itishighlylikelythatothercharacteristicsaswellcanbedetectedwiththistestmethod.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Inch-poundunitsareprovidedforinformationonly.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:C43
【国际标准分类号】:35_240_80
【页数】:5P.;A4
【正文语种】:
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