1、The Institute of Electrical 3 Park Avenue, New York, NY 10016-Copyright 1999 by the InstituAll rights reserved. PublishedIEEE is a registered trademarEngineers, Incorporated.Print: ISBN 0-7381-PDF: ISBN 0-7381-No part of this publication may be written permission of the publisherAmerican National St
2、andard for Determination of Uniformity of Solid Gamma-Emitting Flood SourcesSponsorNational CommitteAccredited by theAmerican National SecretariatThe Institute of ElectricaReaffirmed DecemIEEE-SA Standards BoardApproved 12 May 19American National Abstract: Minimumes used with scintillation camerasuc
3、h information is oogy. In addition, it is characteristics or correcKeywords: flood source, nucTest and MeasuremCopyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,
4、-,-and Electronics Engineers, Inc.5997, USAte of Electrical and Electronics Engineers, Inc.28 May 1999. Printed in the United States of America.k in the U.S. Patent (978) 750-8400. Permission to photocopyportions of any individual standard for educational classroom use can also be obtained through t
5、he Copy-right Clearance Center.Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright The Institute of Electrical and Electronics Engineers, Inc. Provide
6、d by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Introduction(This introduction is not part of ANSI N42.27-1999, American National Standard for Determination of Uniformity ofSolid Gamma-Emitting Flood Sources.)This standard is the res
7、ponsibility of the Accredited Standards Committee N42 on Radiation Instrumenta-tion. Committee N42 delegated the development of this standard to its subcommittee N42.RM. Drafts werereviewed by Committee N42, Subcommittee N42.RM, and other interested parties, and the commentsreceived were utilized in
8、 producing the standard as finally approved. At the time it approved this standard, the Accredited Standards Committee on Radiation Instrumentation,N42, had the following members:Louis Costrell, Chair Sue Vogel, Administrative SecretaryOrganization Represented Name of RepresentativeAmerican Conferen
9、ce of Governmental Industrial Hygienists Jesse LiebermanApplied Safety Technology Edward J. Vallario*Battelle Pacific Northwest Laboratories Joseph C. McDonaldBicron. Joseph G. BellianChew, M. H. . Jack M. SelbyEberline Instrument Company . James K. HeschEG&G ORTEC Sanford WagnerGamma-Metrics . Erne
10、sto A. CorteHealth Physics Society. George CampbellJoseph R. Stencel (Alt.)Institute of Electrical and Electronics Engineers. Louis CostrellJulian Forster (Alt.)Anthony J. Spurgin (Alt.)Lawrence Berkeley Laboratory Edward J. LampoLawrence Livermore National Laboratory. Gary JohnsonLovelace RR Instit
11、ute. Morgan CoxMassachusetts Institute of Technology, Bates Linear Accelerator Center . Frank X. MasseNASA/GSFC, U.S Donald E. Stilwell*Nuclear Standards Unlimited. Al N. TschaecheOak Ridge National Laboratory. Charles L. BrittonSwinth Associates Kenneth L. SwinthU.S. Army Center for EW/RSDA Edward
12、GroeberU.S. Department of Commerce, National Institute of Standards and Technology Louis CostrellMichael Unterweger (Alt.)U.S. Department of Energy/PCSRD Natesh VarmaU.S. Federal Emergency Management Agency . Carl R. SiebentrittMembers-at-Large Paul L. PhelpsLee J. Wagner* DeceasedAt the time this s
13、tandard was approved, Subcommittee N42.RM had the following members:Frank X. Masse, Chair J. M. R. Hutchinson, SecretaryRobert AyresJoseph G. BellianJohn D. BuchananR. F. ColeyBert M. CourseyMichael DevineRoger FerrisRobert J. GehrkeY. KobayshiMarkku KoskeloJoel L. LazewatskyDavid E. McCurdyD. M. Mo
14、ntgomeryCarl W. SeidelJohn SonewaldMichael UnterwegerCopyright 1999 IEEE. All rights reserved. iiiCopyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-The workin
15、g group for this standard had the following members:Joel L. Lazewatsky, Chair and project leader The following persons were on the balloting committee that approved this document for submission to theAmerican National Standards Institute:*DeceasedCatherine K.N. BergerIEEE Standards Project EditorLou
16、 EdmondFrederic FaheyMarvin FriedmanL. Stephen GrahamThomas KumpurisCarl W. SeidelDavid WeberJoseph G. BellianCharles L. BrittonGeorge CampbellErnesto A. CorteLouis CostrellMorgan CoxJulian ForsterJohn M. GallagherGerald GoldsteinEdward GroeberJames K. HeschGary JohnsonEdward J. LampoJesse Lieberman
17、Frank X. MasseJoseph C. McDonaldPaul L. PhelpsJack M. SelbyCarl R. SiebentrittDonald E. Stilwell*Anthony J. SpurginJoseph R. StencelKenneth L. SwinthAl N. TschaecheMichael UnterwegerEdward J. Vallario*Natesh VarmaLee J. WagnerSanford Wagneriv Copyright 1999 IEEE. All rights reserved.Copyright The In
18、stitute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Contents1. Introduction 11.1 Scope 11.2 Special word usage 12. References 23. Definitions 24. Procedure requirements . 34.1
19、Test and Measurement Report . 34.2 Required reportable parameters . 34.3 Methodological requirements 44.4 Constancy of system response . 54.5 Detailed method of measurement 65. Precautions and sources of error 65.1 Dependence upon measurement orientation 65.2 Backscatter and surrounding geometry 65.
20、3 Interference from nearby sources. 65.4 Calculation error 6Annex A (informative) Methodological example . 7Copyright 1999 IEEE. All rights reserved. vCopyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or network
21、ing permitted without license from IHS-,-,-American National Standard for Determination of Uniformity of Solid Gamma-Emitting Flood Sources1. IntroductionNuclear medicine practitioners use solid, uniformly radioactive sources that are several millimeters thickwith areas up to 0.25 m2(called “flood”
22、sources) to characterize and correct the extrinsic flood field unifor-mity of scintillation cameras for purposes of both quality assurance and on-line operational corrections.These radioactive sources are intended to produce a uniform radiation field across the cameras usable fieldof view. Methods t
23、o evaluate camera uniformity are described in NEMA NU 1-1994.1A broad range of flood sources is available in many sizes and configurations from a number of manufactur-ers. Such diversity suggests the need for a uniform means of reporting calibration data and a common under-standing of the parameters
24、 reported. This information can permit intercomparison of sources and givepractitioners a means to determine whether a particular source is appropriate for a given task.1.1 ScopeThe scope of this standard is limited to commercially-produced, solid radioactive flood sources intended toaid in the dete
25、rmination of the system field uniformity of scintillation cameras used in nuclear medicine.This standard is intended to provide a set of minimum informational requirements for a Test and Measure-ment Report for flood sources used with scintillation cameras. It is not intended to specify the means by
26、which such information is obtained, although it does place requirements and limitations on the methodology.In addition, it is not intended to cover the use of the source in the determination of the operating characteris-tics or correction factors for a scintillation camera.1.2 Special word usageThe
27、words shall or must indicate a procedure that is necessary to meet the requirements of this standard. Thewords should or may indicate an advisory recommendation that is to be applied when practicable.1Information on references can be found in Clause 2.Copyright 1999 IEEE. All rights reserved. 1ANSIN
28、42.27-1999 AMERICAN NATIONAL STANDARD FOR DETERMINATION OFCopyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2. ReferencesThis standard shall be used in conjun
29、ction with the following publications. If the following publications aresuperseded by an approved revision, the revision shall apply.ASTM E456-96, Standard Terminology for Relating to Quality and Statistics.2NEMA NU 1-1994, Performance Measurements of Scintillation Cameras.33. DefinitionsFor the pur
30、poses of this standard, the following terms and definitions apply:3.1 accuracy: The closeness of agreement between a test result and an accepted reference value. (The word“accuracy” is to be understood as it is defined in ASTM E456-96.) 3.2 penumbra: The area over which the sensitivity of the measur
31、ement system falls from 90% of its maxi-mum value within the unit cell to 10% of that value.3.3 statistical terminology: See: accuracy and uncertainty. 3.4 uncertainty: An indication of the variability associated with a measured value that takes into accounttwo major components of error: 1) bias, an
32、d 2) the random error attributed to the imprecision of the measure-ment process. (The word “uncertainty” is to be understood as it is defined in ASTM E456-96.)3.5 uniformity: A quantitative description of the two-dimensional distribution of the photon flux emitted bya radioactive flood source, descr
33、ibing variations in that flux for specified areas.3.6 unit cell (UC): An area on the source to which a single localized measurement value applies. The UC isthe two-dimensional region (in the plane of the measured surface of a source) defined by the response of themeasurement system to a point source
34、 located in the plane of the source and of the same radioactive compo-sition as the flood source.The UC encloses all points at which the sensitivity of the system is equal to or greater than half that of themaximum value measured.NOTES:1. For this standard, the area of the UC should be 1 cm2or less,
35、 but in no case shall it be greater than 6.5 cm2.2. This standard may not be construed as to imply any ability to determine the presence of defects smaller than one UC.3.7 useful region (UR): The region of the source within which all measurements are made and for which allare certified to be correct
36、. All measurements shall be performed and reported for the UR, recognizing thatmeasurement asymmetries are likely to be present at the edge of the source. The source may extend outsidethe UR, but no claim is made as to uniformity outside of the UR.2ASTM publications are available from the American S
37、ociety for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken,PA 19428-2959, USA (http:/www.astm.org/).3NEMA publications are available from Global Engineering Documents, 15 Inverness Way East, Englewood, Colorado 80112, USA(http:/ Copyright 1999 IEEE. All rights reserved.ANSIUNIFORMITY
38、 OF SOLID GAMMA-EMITTING FLOOD SOURCES N42.27-1999Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS4. Procedure requirements4.1 Test and Measurement ReportEach fl
39、ood source shall be accompanied by a Test and Measurement Report that shall contain the followinginformation: The primary radionuclide and all measurable radioactive impurities (as defined in 4.2) and theamount of radioactivity of each. The spatial uniformity of the emitted photon flux in terms of a
40、ll required parameters described in thisstandard. The method by which these quantities have been measured. A summary of the statistical analysis of the data sufficient to determine the bias and imprecision ofmeasurement throughout the analysis of a given source. A description of the system constancy
41、 procedure as discussed in 4.4. A statement that the measurement system is maintained, calibrated, and validated using a validatedStandard Operating Procedure (SOP). A statement that the source was evaluated using a validated SOP that conforms to the requirementsof current good manufacturing practic
42、e (cGMP) or equivalent.4.2 Required reportable parametersThe following parameters shall be reported in the Test and Measurement Report: The primary and impurity radionuclide content at the time of calibration shall be reported to an accu-racy of 10% at the 95% confidence level. All radionuclide spec
43、ies present in the source at concen-trations greater than 0.05% of the activity of the primary radionuclide shall be listed individually.Total radionuclide impurity concentration shall be reported with an accuracy of 10% (at the 95%confidence level). A calculated estimate of the primary and impurity
44、 radionuclide content at a time equal to two half-lives (from the date of manufacture) of the primary radionuclide shall be reported. This shall be inthe same form as used in the impurity report described in the previous paragraph. This will report theconcentrations of all radionuclides reported in
45、the initial impurity report as well as any other knownimpurities that are estimated to be present in concentrations greater than 0.05% of the primary radi-onuclide at the later time. The shape and dimensions of the unit cell (UC) in the normal counting geometry, including the widthof the penumbra (t
46、he area over which the sensitivity of the measurement system falls from 90% ofits maximum value within the UC to 10% of that value) shall be reported. A complete description of the cluster in terms of size, shape, and distribution within the useful region(UR).For the entire UR, the following shall b
47、e reported: The number of UC measurements, the mean, and the measured sample standard deviation of the UCcount for the entire UR. The Maximum Absolute Deviation from the Mean (MADM), defined by the largest sample differ-ence from the mean UC value, expressed as a percentage of the mean UC value. The
48、 Coefficient of Variation (CV), defined by the standard deviation of the distribution of UC valuesdivided by the mean UC value and expressed as a percentage.Copyright 1999 IEEE. All rights reserved. 3-,-,-ANSIN42.27-1999 AMERICAN NATIONAL STANDARD FOR DETERMINATION OFCopyright The Institute of Elect
49、rical and Electronics Engineers, Inc. Provided by IHS under license with IEEENot for ResaleNo reproduction or networking permitted without license from IHS-,-,- The Integral Uniformity (IU), in percent, defined as 100 (UCmax UCmin)/(UCmax + UCmin), whereUCmax represents the largest and UCmin the smallest UC measurement acquired over the UR, re
