1、Designation:E164709Standard Practice forDetermining Contrast Sensitivity in Radiology1This standard is issued under the fixed designation E1647;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 par
2、entheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the design and material selection ofa contrast sensitivity measuring gauge used to determine theminimum change in material thicknes
3、s or density that may beimaged without regard to spatial resolution limitations.1.2 This practice is applicable to transmitted-beam radio-graphic and radioscopic imaging systems utilizing X-ray andgamma ray radiation sources.1.3 The values stated in inch-pound units are to be regardedas standard.The
4、 SI units given in parentheses are for informa-tion only.1.4 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
5、of regulatory limitations prior to use.For specific safetystatements,see NIST/ANSI Handbook 114 Section 8,Code ofFederal Regulations 21 CFR 1020.40 and 29 CFR 1910.96.2.Referenced Documents2.1 ASTM Standards:2B139/B139M Specification for Phosphor Bronze Rod,Bar,and ShapesB150/B150M Specification for
6、 Aluminum Bronze Rod,Bar,and ShapesB161 Specification for Nickel Seamless Pipe and TubeB164 Specification for Nickel-Copper Alloy Rod,Bar,andWireB166 Specification for Nickel-Chromium-Iron Alloys(UNSN06600,N06601,N06603,N06690,N06693,N06025,N06045,andN06696),Nickel-Chromium-Cobalt-Molybdenum Alloy(U
7、NS N06617),and Nickel-Iron-Chromium-Tungsten Alloy(UNS N06674)Rod,Bar,andWireE747 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 Classifi
8、cation of Hole-Type Image Quality In-dicators(IQI)Used for RadiologyE1255 Practice for RadioscopyE1316 Terminology for Nondestructive ExaminationsE1411 Practice for Qualification of Radioscopic SystemsE2002 Practice for Determining Total Image Unsharpness inRadiologyE2445 Practice for Performance Ev
9、aluation and Long-TermStability of Computed Radiography Systems2.2 Federal Standards:321 CFR 1020.40 Safety Requirements for Cabinet X-raySystems29 CFR 1910.96 Ionizing Radiation2.3 NIST/ANSI Standards:NIST/ANSI Handbook 114 General Safety Standard forInstallations Using Non-Medical X-ray and Sealed
10、Gamma Ray Sources,Energies to 10 MeV42.4 Other Standard:5EN 462 5 Duplex Wire Image Quality IndicatorEN 130681 Radioscopic Testing-Part 1:Qualitative Mea-surement of Imaging Properties3.Terminology3.1 DefinitionsDefinitions of terms applicable to this testmethod may be found in Terminology E1316.4.S
11、ummary of Practice4.1 It is often useful to evaluate the contrast sensitivity of apenetrating radiation imaging system separate and apart fromspatial resolution measurements.Conventional image qualityindicators(IQIs),such as Test Method E747 wire and PracticeE1025 plaque IQIs,combine the contrast se
12、nsitivity and1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology(X and Gamma)Method.Current edition approved July 1,2009.Published August 2009.Originallyapproved in 1994.Last previous edition ap
13、proved in 2003 as E1647 03.DOI:10.1520/E1647-09.2For 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.3Available from U.
14、S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.4Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.5Available from British
15、Standards Institute(BSI),389 Chiswick High Rd.,London W4 4AL,U.K.,http:/www.bsi-.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 resolution measurements into an overall performance figure ofmerit,other methods such as included in Practice
16、 E2002 do notaddress contrast specifically.Such figures of merit are often notadequate to detect subtle changes in imaging system perfor-mance.For example,in a high contrast image,spatial resolu-tion can degrade with almost no noticeable effect upon overallimage quality.Similarly,in an application in which the imagingsystem provides a very sharp image,contrast can fade withlittle noticeable effect upon the overall image quality.Thesesituations often develop and may go unnoticed until the systemp