1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA NU 1-2012Performance Measurements of Gamma CamerasNEMA Standards Publication NU 1-2012 Performance Measurements of Gamma Cameras Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 R
2、osslyn, Virginia 22209 www.nema.org www.medicalimaging.org 2013 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the In
3、ternational and Pan American copyright conventions. NOTICE AND DISCLAIMER The information in this publication was considered technically sound by a consensus among persons engaged in its development at the time it was approved. Consensus does not necessarily mean there was unanimous agreement among
4、every person participating in the development process. The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document herein is one, are developed through a voluntary standards development process. This process brings together volunteers and/or s
5、eeks out the views of persons who have an interest in the topic covered by this publication. Although NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the documents, nor does it independently test, evaluate, or verify the accur
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8、 will fulfill any particular purpose(s) or need(s). NEMA does not undertake to guarantee the performance of any individual manufacturers or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render profession
9、al or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in de
10、termining the exercise of reasonable care in any given circumstance. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power
11、, nor does it undertake to police or enforce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health- or safety-related information in
12、this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. NU 1-2012 Page i 2013 National Electrical Manufacturers Association CONTENTS Page SECTION 1 SCOPE 1 1.1 DEFINITIONS 1 1.2 REFERENCES 4 1.3 TEST EQUIPMENT, CONDITIONS, AND RESU
13、LTS . 4 1.3.1 Source Holders and Test Fixtures . 4 1.3.2 Radiation Sources . 4 1.3.3 Test Conditions 5 1.3.4 Reporting . 5 SECTION 2 TESTS OF GAMMA CAMERA DETECTORS . 6 2.1 INTRINSIC SPATIAL RESOLUTION 6 2.1.1 Test Conditions 6 2.1.2 Test Equipment . 7 2.1.3 Measurement Procedure . 7 2.1.4 Calculati
14、ons and Analysis 8 2.1.5 Reporting . 10 2.2 INTRINSIC SPATIAL LINEARITY . 10 2.2.1 Test Conditions 10 2.2.2 Test Equipment . 10 2.2.3 Measurement Procedure . 10 2.2.4 Calculations and Analysis 11 2.2.5 Reporting . 11 2.3 INTRINSIC ENERGY RESOLUTION 11 2.3.1 Test Conditions 12 2.3.2 Test Equipment .
15、12 2.3.3 Measurement Procedure . 12 2.3.4 Calculations and Analysis 12 2.3.5 Reporting . 13 2.4 INTRINSIC FLOOD FIELD UNIFORMITY 13 2.4.1 Test Conditions 13 2.4.2 Test Equipment . 13 2.4.3 Measurement Procedure . 13 2.4.4 Calculations and Analysis 14 2.4.5 Reporting . 15 2.5 MULTIPLE WINDOW SPATIAL
16、REGISTRATION 15 2.5.1 Test Conditions 16 2.5.2 Test Equipment . 16 2.5.3 Measurement Procedure . 16 2.5.4 Calculations and Analysis 17 2.5.5 Reporting . 18 2.6 INTRINSIC COUNT RATE PERFORMANCE IN AIR . 18 2.6.1 Decaying Source Method 18 2.6.2 Intrinsic Count Rate Performance in AirCopper Plates Meth
17、od 21 2.7 INTRINSIC SPATIAL RESOLUTION AT 75,000 COUNTS PER SECOND . 25 2.8 INTRINSIC FLOOD FIELD UNIFORMITY AT 75,000 COUNTS PER SECOND . 25 SECTION 3 TESTS OF GAMMA CAMERA DETECTORS WITH COLLIMATORS . 26 3.1 SYSTEM SPATIAL RESOLUTION WITHOUT SCATTER 26 3.1.1 Test Conditions 26 3.1.2 Test Equipment
18、 . 26 NU 1-2012 Page ii 2013 National Electrical Manufacturers Association 3.1.3 Measurement Procedure . 26 3.1.4 Calculations and Analysis 27 3.1.5 Reporting . 27 3.2 SYSTEM SPATIAL RESOLUTION WITH SCATTER . 27 3.2.1 Test Conditions 27 3.2.2 Test Equipment . 27 3.2.3 Measurement Procedure . 27 3.2.
19、4 Calculations and Analysis 28 3.2.5 Reporting . 28 3.3 SYSTEM PLANAR SENSITIVITY AND COLLIMATOR PENETRATION AND SCATTER . 28 3.3.1 Test Conditions 28 3.3.2 Test Equipment . 29 3.3.3 Measurement Procedure . 29 3.3.4 Calculations and Analysis 29 3.3.5 Reporting . 31 3.3.6 Referenced Documents . 31 3.
20、4 DETECTOR SHIELDING 31 3.4.1 Test Conditions 31 3.4.2 Test Equipment . 32 3.4.3 Measurement Procedure . 32 3.4.4 Calculations and Analysis 33 3.4.5 Reporting . 34 3.5 SYSTEM COUNT RATE PERFORMANCE WITH SCATTER 34 3.5.1 Test Conditions 34 3.5.2 Test Equipment . 34 3.5.3 Measurement Procedure . 35 3.
21、5.4 Calculations and Analysis 36 3.5.5 Reporting . 36 SECTION 4 TESTS SPECIFIC TO GAMMA CAMERA TOMOGRAPHIC SYSTEMS 37 4.1 SYSTEM ALIGNMENT 37 4.1.1 Test Conditions 37 4.1.2 Test Equipment . 37 4.1.3 Measurement Procedure . 38 4.1.4 Calculations and Analysis 38 4.1.5 Reporting . 40 4.2 SPECT RECONSTR
22、UCTED SPATIAL RESOLUTION WITHOUT SCATTER . 40 4.2.1 Test Conditions 40 4.2.2 Test Equipment . 40 4.2.3 Measurement Procedure . 40 4.2.4 Calculations and Analysis 40 4.2.5 Reporting . 42 4.3 SPECT RECONSTRUCTED SPATIAL RESOLUTION WITH SCATTER 42 4.3.1 Test Conditions 42 4.3.2 Test Equipment . 42 4.3.
23、3 Measurement Procedure . 43 4.3.4 Calculations and Analysis 44 4.3.5 Reporting . 44 4.4 SYSTEM VOLUME SENSITIVITY. 44 4.4.1 Test Conditions 45 4.4.2 Test Equipment . 45 4.4.3 Measurement Procedure . 45 4.4.4 Calculations and Analysis 46 4.4.4 Reporting . 46 NU 1-2012 Page iii 2013 National Electric
24、al Manufacturers Association 4.5 DETECTOR-DETECTOR SENSITIVITY VARIATION 46 4.5.1 Test Equipment . 47 4.5.2 Measurement Procedure . 47 4.5.3 Calculations and Analysis 47 4.5.4 Reporting . 47 SECTION 5 TESTS SPECIFIC TO GAMMA CAMERA WHOLE-BODY SCANNING SYSTEMS 48 5.1 WHOLE-BODY SYSTEM SPATIAL RESOLUT
25、ION WITHOUT SCATTER 48 5.1.1 Test Conditions 48 5.1.2 Test Equipment . 48 5.1.3 Measurement Procedure . 49 5.1.4 Calculation and Analysis . 49 5.1.5 Reporting . 50 5.1.6 Rationale 50 FIGURES Page Figure 21 Collimated Source Geometry 7 Figure 22 Lead Masks for Measurement of Spatial Resolution and Li
26、nearity 8 Figure 23 Determination of FWHM and FWTM 9 Figure 24 Cylindrical Source Holder for Multiple Window Spatial Registration Measurement Showing Liquid Ga-67 Source Inside . 16 Figure 25 Source Holder for Count Rate Measurements . 19 Figure 26 Example Count Rate Curve 21 Figure 31 Source Positi
27、ons for Shield Leakage Measurements . 32 Figure 32 Phantom for Measuring Count Rate Performance in Scatter . 35 Figure 41 Positions of the Three Co-Planar Point Sources for Measuring SPECT Head Alignment and Reconstructed System Resolution without Scatter . 38 Figure 42 SPECT Reconstructed Spatial R
28、esolution with Scatter 43 Figure 43 Calculating Reconstructed System Spatial Resolution with Scatter . 44 Figure 44 Volume Sensitivity Cylindrical Phantom . 45 Figure 51 Source Position for Whole Body Resolution Measurements 49 WORKSHEETS Page Worksheet 4-1 Measurements of FWHM from the Central Poin
29、t . 41 Worksheet 4-2 Measurements of FWHM from the Peripheral Points . 41 NU 1-2012 Page iv 2013 National Electrical Manufacturers Association FOREWORD Reason for Changes NEMA NU 1-2012 (hereinafter referred to as NEMA NU 1) was developed by the Molecular Imaging Section of the Medical Imaging used
30、as controlled input for measurement of Gamma camera parameters. useful field of view (UFOV): The area of the detector that is used for imaging Gamma rays and x-rays. It is defined by a dimensioned figure supplied by the manufacturer. 1.2 REFERENCES The following normative documents contain provision
31、s, which through reference in this text, constitute provisions of this Standards Publication. By reference herein, these publications are adopted, in whole or in part as indicated, in this Standards Publication. International Electrotechnical Commission 3, rue de Varembe Case postale 131 CH-1211 Gen
32、eva 20 Switzerland IEC IS 60789 Ed. 3 Medical electrical equipment characteristics and test conditions of radionuclide imaging devices anger type Gamma cameras IEC IS 61675-2 Ed. 1 Amendment 1 Radionuclide imaging devices characteristics and test conditions part 2: Single Photon Emission Computed To
33、mographs (SPECT) IEC IS 61675-3 Radionuclide imaging devices characteristics and test conditions part 3: Gamma camera based whole-body imaging systems U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Guide 10.8 Appendix C Guide for the preparation of applications for medical programs, me
34、thods for calibration of dose calibrators 1.3 TEST EQUIPMENT, CONDITIONS, AND RESULTS 1.3.1 Source Holders and Test Fixtures A number of different source holders are required for performance of the procedures. Each source holder is described in the individual procedure for which it is required. Manu
35、facturing tolerances and materials of source holders are often critical in ensuring precise and reproducible measurements. Care has been taken to make the design of the source holders as simple as possible, consistent with the requirements for precision and accuracy in the measurement procedures. Al
36、l dimensional tolerances shall be 10% unless otherwise specified. Test fixtures that mount physically to the camera may require manufacturer-specific design elements that are not covered in NEMA NU 1. It is recognized that these design elements belong to the camera manufacturer. 1.3.2 Radiation Sour
37、ces Numerous radiation sources with different shapes and amount of activities are required. Most of the tests use Tc-99m. Co-57, however, can often be substituted for Tc-99m as indicated in individual procedures. Ga-67 is required to perform the Multiple Window Spatial Registration procedures. The p
38、rocedures can generally be performed with other radionuclides, provided the radionuclide used is clearly reported with the test results. NU 1-2012 Page 5 2013 National Electrical Manufacturers Association 1.3.3 Test Conditions All measurements shall be performed using cameras in the appropriate clin
39、ical mode of operation. The energy windows utilized for the measurements also should be specified. Any additional tests at variance with the above conditions or test parameters shall be separately reported and the variances clearly indicated. If, for quality assurance or other purposes, the manufact
40、urer employs radionuclides other than those prescribed by this standard, the manufacturer shall demonstrate traceability between the radionuclide prescribed for the measurement and the radionuclide employed. If, for ease of use or other similar purposes, the manufacturer employs specific setup steps
41、 or procedures in order to augment those prescribed by this standard, the manufacturer may specify these added steps for the measurement and the procedure employed as part of the results. If the manufacturer chooses to allow a higher count rate ceiling in individual sections prescribed by this stand
42、ard in order to shorten the duration of these measurements, the manufacturer may specify these limits for the measurement. 1.3.4 Reporting For each test described, this standard specifies whether the system is expected to “meet or exceed” the manufacturers specification, or if the specification is c
43、onsidered “typical” performance. For most tests in this standard, the system shall “meet or exceed” the manufacturers specification. “Typical” specifications are used in two cases: a) When the measurement is inherently so time-consuming that measuring large numbers of units is considered unduly burd
44、ensome, such as in these tests: i.Intrinsic Count Rate Performance in AirDecaying Source Method (Section 2.6) ii.System Count Rate Performance with Scatter (Section 3.5) b) When there are inherent difficulties in obtaining a sufficiently accurate measurement in a manufacturing or hospital environmen
45、t, such as in these tests: i.Intrinsic Count Rate Performance in AirCopper Plates Method (Section 2.6.2) ii.System Planar Sensitivity and Collimator Penetration and Scatter (Section 3.3) iii.System Volume Sensitivity (Section 4.4) iv.Detector-Detector Sensitivity Variation (Section 4.5) NU 1-2012 Pa
46、ge 6 2013 National Electrical Manufacturers Association Section 2 TESTS OF GAMMA CAMERA DETECTORS 2.1 INTRINSIC SPATIAL RESOLUTION Intrinsic spatial resolution measurements shall meet or exceed the specification. NOTE: For discrete pixel detectorsThe measurement and analysis of intrinsic spatial res
47、olution as defined below for single crystal cameras is not directly applicable to that of discrete pixel detectors. The spatial resolution of these systems may be characterized using the system spatial resolution measurement described in Section 3.1. 2.1.1 Test Conditions The radionuclide employed f
48、or this test shall be Tc-99m. A source holder that shields the source from walls, ceilings and personnel without restricting the Gamma flux from the source to the camera (as shown in Figure 21) shall be employed. One or more copper plates (Figure 21) may be used to adjust the count rate. The energy
49、window for Tc-99m shall be that recommended by the manufacturer for the appropriate clinical mode. The count rate shall not exceed 20,000 cps through the energy window with the test pattern in place. NU 1-2012 Page 7 2013 National Electrical Manufacturers Association Figure 21 Collimated Source Geometry If other radionuclides are used, the energy window should be set according to the manufacturers recommendations. 2.1.2 Test Equipment The test pattern shall consist of a lead mask with 1 mmwide parallel slits. The test pattern shall be pos
