1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA NU 4-2008Performance Measurements of Small Animal Positron Emission TomographsNEMA Standards Publication NU 4-2008 Performance Measurements of Small Animal Positron Emission Tomographs Published by: National Electrical Manuf
2、acturers Association 1300 N. 17th Street, Suite 1752 Rosslyn, VA 22209 www.nema.org Contains December 22, 2011 Errata Copyright 2008 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Ber
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10、r her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may w
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12、Any certification or other statement of compliance with any health or safety-related information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. NU 4-2008 Page i Copyright 2008 by the National Electrical Manufacturers As
13、sociation. CONTENTS Page Foreword iii Scope . iii Section 1 DEFINITIONS 1 1.1 Definitions 1 1.2 Standard Symbols . 1 Section 2 GENERAL . 4 2.1 Purpose . 4 2.2 Purview 4 2.3 Units of Measure . 4 2.4 Consistency . 4 2.5 Equivalency . 5 Section 3 SPATIAL RESOLUTION . 6 3.1 General 6 3.2 Purpose . 6 3.3
14、 Method . 6 3.3.1 Symbols . 6 3.3.2 Radionuclide 6 3.3.3 Source Distribution 6 3.3.4 Data Collection 7 3.3.5 Data Processing 7 3.4 Analysis . 7 3.5 Report 8 Section 4 SCATTER FRACTION, COUNT LOSSES, AND RANDOM COINCIDENCE MEASUREMENTS 9 4.1 General 9 4.2 Purpose . 9 4.3 Method . 10 4.3.1 Symbols . 1
15、0 4.3.2 Radionuclide 10 4.3.3 Source Distribution 11 4.3.4 Data Collection 11 4.3.5 Data Processing 12 4.4 Analysis . 12 4.4.1 Scatter Fraction . 13 4.4.2 Total Event Rate Measurement 13 4.4.3 True Event Rate Measurement . 14 4.4.4 Random Event Rate Measurement . 14 4.4.5 Scattered Event Rate Measur
16、ement . 14 4.4.6 Noise Equivalent Count Rate Measurement . 14 4.5 Report 15 4.5.1 Count Rate Plot . 15 4.5.2 Peak Count Rate Values . 15 4.5.3 System Scatter Fraction 15 Section 5 SENSITIVITY . 16 5.1 General 16 5.2 Purpose . 16 5.3 Method . 16 5.3.1 Symbols . 16 5.3.2 Radionuclide 17 NU 4-2008 Page
17、 ii Copyright 2008 by the National Electrical Manufacturers Association. 5.3.3 Source Distribution 17 5.3.4 Data Collection 17 5.4 Calculations and Analysis 17 5.4.1 System Sensitivity . 17 5.5 Report 18 Section 6 IMAGE QUALITY, ACCURACY OF ATTENUATION, AND SCATTER CORRECTIONS. 19 6.1 General 19 6.2
18、 Purpose . 19 6.3 Method . 19 6.3.1 Symbols . 19 6.3.2 Radionuclide 19 6.3.3 Source Distribution 20 6.3.4 Data Collection 21 6.3.5 Data Processing 21 6.4 Analysis . 22 6.4.1 Uniformity 22 6.4.2 Recovery Coefficients . 22 6.4.3 Accuracy of Corrections 22 6.5 Report 22 Tables 3-1 Resolution Values Rep
19、orted . 8 6-1 Report for Uniformity Test . 23 6-2 Report for Recovery Coefficient Test 23 6-3 Report for Accuracy of Corrections . 23 Figures 3-1 Positions of Source for Resolution Measurement . 7 3-2 A Typical Response Function With FWHM and FWTM Determined by Interpolation . 8 4-1 Positioning of P
20、hantom 11 4-2 Integration of Background Counts Inside and Outside 14 mm Strip . 13 6-1 Image Quality Phantom. Coronal and Transverse Sections through the Main Phantom Body, Top Cover, and Bottom Cover 21 NU 4-2008 Page iii Copyright 2008 by the National Electrical Manufacturers Association. FOREWORD
21、 SCOPE The scope of this document is to propose a standardized methodology for evaluating the performance of positron emission tomographs (PET) designed for animal imaging. The objective is to establish a baseline of system performance in typical imaging conditions, and a concerted effort has been m
22、ade to develop a procedure that is independent of camera design and applicable to a wide range of camera models and geometries. Camera designs such as circular ring geometry of discrete crystal or continuous block detectors, planar detector (rotating or stationary), continuous crystals, gas avalanch
23、e detectors, time-of-flight or non time-of-flight, single slice or multi-slice dedicated PET tomographs and other coincidence-capable imaging systems are covered by this procedure. It is understood that every system to be tested under this standard is able to create transverse sinograms and transver
24、se slice images with a standard, filtered backprojection, image reconstruction algorithm. The software provided or recommended by the manufacturer should be able to accomplish basic functions such as defining and manipulating two-dimensional regions-of-interest (with circular and rectangular profile
25、s), the ability to define linear profiles, and permit extraction of data such as coincidence event counts detected within specified intervals of acquisition time. Tomographs must have a transverse field of view of at least 33.5 mm in diameter to be tested against all standards. It is assumed that th
26、e isotope 18F (and/or 11C) is available in sufficient quantity and concentration to perform the tests as described in the standard, and the site performing the test has access to a dose-calibrator, or similar device, calibrated against a standard reference radioactive source. These specifications re
27、present a subset of measurements that characterize the performance of positron emission tomographs for specific imaging tasks typically encountered in small laboratory animal imaging facilities. This subset is deemed to be common across all tomographs existing at the time of writing. This standards
28、publication was developed by the Animal PET Standard Task Force chartered by the Nuclear Section. Committee approval of the standard does not necessarily imply that all committee members voted for its approval or participated in its development. At the time it was approved, the Task Force was compos
29、ed of the following members: Nicola Belcari Universita di Pisa, Pisa, Italy Michael Britton GE Healthcare, Waukesha, Wisconsin Peter Bruyndonckx Vrije Universiteit Brussel, Brussels, Belgium Arion Chatziioannou UCLA, Los Angeles, California John Clark University of Cambridge, Cambridge, U.K. Andrea
30、Cremoncini I.S.E. srl, Pisa, Italy Margaret Daube-Witherspoon Research Consultant, Fairfax Station, Virginia Alberto Del Guerra University of Pisa, Pisa, Italy Mary Anne Dell-Yusko Capintec, Inc., Pittsburgh, Pennsylvania Gunter Dietzel Raytest, Straubenhardt, Germany Tim Fryer Cambridge University,
31、 Cambridge, U.K. Alan Jeavons Oxford Positron Systems Ltd., Oxfordshire, U.K. Joel Karp University of Pennsylvania, Philadelphia, Pennsylvania Raffi Kayayan Philips Medical Systems, Cleveland, Ohio David Keating Varian Medical Systems, South Elgin, Illinois Jeffrey Kolthammer Philips Medical Systems
32、, Cleveland, Ohio Richard Laforest Washington University, St. Louis, Missouri Marco Lazzarotti I.S.E. srl, Pisa, Italy Jose Maria Ortega Jimenez SUINSA SLL, Madrid, Spain Robert Miyaoka University of Washington, Seattle, Washington Bradley Patt Gamma Medica-Ideas, Inc., Northridge, California Bernd
33、Pichler Klinikum reachts derisar TechniUniversiteit, Munich, Germany NU 4-2008 Page iv Copyright 2008 by the National Electrical Manufacturers Association. Paul Picot GE Healthcare, Waukesha, Wisconsin Gilberto Prudencio GE Healthcare, Waukesha, Wisconsin Juergen Seidel Johns Hopkins University, Bet
34、hesda, Maryland Vitali Selivanov Gamma Medica-Ideas, Inc., Northridge, California Yiping Shao M.D. Anderson Cancer Center, Houston, Texas Stefan Siegel Siemens Molecular Imaging Knoxville, Tennessee Vilim Simcic Hologic, Inc., Santa Clara, California Terry Spinks Imaging Research Solutions Limited,
35、London, U.K. Suleman Surti University of Pennsylvania, Philadelphia, Pennsylvania Yuan-Chuan Tai Washington University, St. Louis, Missouri Jorge Uribe GE Global Research, Niskayuna, New York Juan Jose Vaquero Hospital General Universitario Gregorio Maranon, Madrid, Spain Phil Vernon GE Healthcare,
36、Aurora, Ohio Stefan Vollmar Max Planck Institute for Neurological Research, Cologne, Germany Douglas Wagenaar Gamma Medica-Ideas, Inc., Northridge, California Simone Weber Central Electronics Laboratory, Juelich, Germany Gary Wong University of Texas, M.D. Anderson Cancer Center, Houston, Texas Shup
37、ing Xie Philips Medical Systems, Cleveland, Ohio NU 4-2008 Page 1 Copyright 2008 by the National Electrical Manufacturers Association. Section 1 DEFINITIONS 1.1 DEFINITIONS The axial field-of-view (FOV) is the maximum length parallel to the long axis of a positron emission tomograph along which the
38、instrument generates transaxial tomographic images. Prompt counts represent coincidence events acquired in the standard coincidence window of a positron emission tomograph. Prompt counts include true, scattered and random coincidence events. Sinogram - A two dimensional projection space representati
39、on of a transaxial image where one dimension refers to radial distance from the center and the second dimension refers to projection angle. The transverse field-of-view (FOV) is the maximum diameter circular region perpendicular to the long axis of a positron emission tomograph within which objects
40、might be imaged. Test phantom components for each measurement are defined in the description of that measurement. 1.2 STANDARD SYMBOLS Symbolic expressions for certain quantities are used throughout this Standard. Symbols which use any one of the standard subscripts to further specify a basic quanti
41、ty are identified by the subscript string xxx. All quantities expressed as a function of some independent variable shall be symbolically represented as Q(x), where x is a lower case letter representing the variable as defined in the related text. Only those symbols which are used in multiple section
42、s of the Standard are listed in this section. Symbols which are only used in one section of the Standard are described in that section. Counts (Cxxx) the number of coincidence events: CROI events in a planar region of interest CTOT total number of events Cm maximum number of events Cr estimated rand
43、om event count Cr+s estimated random-plus-scattered event count CL event count at left edge of projection area of interest. CR event count at right edge of projection area of interest. CH counts in a hot region of interest CB counts in a background region of interest CC counts in a cold region of in
44、terest Activity (Axxx) a nuclear decay rate in units of megabecquerels, i.e., in units of 1 million disintegrations per second, and optionally expressed in units of millicuries, i.e., in units of 37 million disintegrations per second: A0 initial activity at T0 Aave,j average activity for jth acquisi
45、tion Acal activity at time Tcal NU 4-2008 Page 2 Copyright 2008 by the National Electrical Manufacturers Association. The initial activity at the beginning (T0) of an acquisition shall be found using the activity Acal as recorded in the dose calibrator or well counter at time Tcal according to: 2lne
46、 x p 2/1T TTAA ca lca l 00 , Where T1/2 is the half-life of the radioisotope. The average activity for a particular acquisition shall be found using the activity, A0, at the beginning of the acquisition, the half-life of the radionuclide, T1/2, and the duration of the acquisition, Tacq, according to
47、: 2TT1TT2AA 21 a c qa c q210a v e lne x pln /The initial activity Aj shall be determined by the dose calibrator or well counter activity measure Acal, decay corrected to the starting time, Tj of the jth acquisition, using the following equation: A j A ca l exp T ca l T jT1 / 2 ln 2 Activity concentr
48、ation (axxx) a nuclear decay rate per unit volume in units of megabecquerels per milliliter, i.e., in units of 1 million decays per second per milliliter, and optionally expressed in units of millicuries per milliliter, i.e., in units of 37 million decays per second per milliliter: at,peak activity
49、concentration at peak true event rate aeff effective average activity concentration of a line source in a solid cylinder aH activity concentration in a hot sphere aB activity concentration in the background aNEC,peak activity concentration at the peak NECR rate The activity concentration of a quantity of radioactivity distributed uniformly through a volume V shall be found by dividing the activity, Axxx, by the volume V within whic
