ASTM_E_2736_-_10.pdf

Designation:E273610Standard Guide forDigital Detector Array Radiology1This standard is issued under the fixed designation E2736;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This standard is a user guide,which is intended to serveas a tutorial for selection and use of various digital detectorarray systems nominally composed of the detector array and animaging system to perform digital radiography.This guide alsoserves as an in-detail reference for the following standards:Practices E2597,E2698,and E2737.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E94 Guide for Radiographic ExaminationE155 Reference Radiographs for Inspection of Aluminumand Magnesium CastingsE192 Reference Radiographs of Investment Steel Castingsfor Aerospace ApplicationsE747 Practice for Design,Manufacture and Material Group-ing Classification of Wire Image Quality Indicators(IQI)Used for RadiologyE1000 Guide for RadioscopyE1025 Practice for Design,Manufacture,and MaterialGrouping Classification of Hole-Type Image Quality In-dicators(IQI)Used for RadiologyE1316 Terminology for Nondestructive ExaminationsE1320 Reference Radiographs for Titanium CastingsE1742 Practice for Radiographic ExaminationE1815 Test Method for Classification of Film Systems forIndustrial RadiographyE1817 Practice for Controlling Quality of Radiological Ex-amination by Using Representative Quality Indicators(RQIs)E2002 Practice for Determining Total Image Unsharpness inRadiologyE2422 Digital Reference Images for Inspection of Alumi-num CastingsE2445 Practice for Performance Evaluation and Long-TermStability of Computed Radiography SystemsE2446 Practice for Classification of Computed RadiologySystemsE2597 Practice for Manufacturing Characterization of Digi-tal Detector ArraysE2660 Digital Reference Images for Investment Steel Cast-ings for Aerospace ApplicationsE2669 Digital Reference Images for Titanium CastingsE2698 Practice for Radiological Examination Using DigitalDetector ArraysE2737 Practice for Digital Detector Array PerformanceEvaluation and Long-Term Stability3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 digital detector array(DDA)systeman electronicdevice that converts ionizing or penetrating radiation into adiscrete array of analog signals which are subsequently digi-tized and transferred to a computer for display as a digitalimage corresponding to the radiation energy pattern impartedupon the input region of the device.The conversion of theionizing or penetrating radiation into an electronic signal maytranspire by first converting the ionizing or penetrating radia-tion into visible light through the use of a scintillating material.These devices can range in speed from many minutes perimage to many images per second,up to and in excess ofreal-time radioscopy rates(usually 30 frames per seconds).3.1.2 signal-to-noise ratio(SNR)quotient of mean valueof the intensity(signal)and standard deviation of the intensity(noise).The SNR depends on the radiation dose and the DDAsystem properties.3.1.3 normalized signal-to-noise ratio(SNRn)SNR nor-malized for basic spatial resolution(see Practice E2445).3.1.4 basic spatial resolution(SRb)basic spatial resolu-tion indicates the smallest geometrical detail,which can beresolved using the DDA.It is similar to the effective pixel size.1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.01 on Radiology(X and Gamma)Method.Current edition approved April 15,2010.Published July 2010.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.5 effciencydSNRn(see 3.1.6 of Practice E2597)di-vided by the square root of the dose(in mGy)and is used tomeasure the response of the detector at different beam energiesand qualities.3.1.6 achievable contrast sensitivity(CSa)optimum con-trast sensitivity(see Terminology E1316 for a definition ofcontrast sensitivity)obtainable using a standard phantom withan X-ray technique that has little contribution from scatter.3.1.7 specific material thickness range(SMTR)materialthickness range within which a given image quality isachieved.3.1.8 contrast-to-noise ratio(CNR)quotient of the d