1、Medical electrical equipment Characteristics of digital X-rayimaging devices Part 1-3: Determination of the detective quantum efficiency Detectors used in dynamic imagingBS EN 62220-1-3:2008raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British S
2、tandardsLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSINational forewordThis British Standard is the UK implementation of EN 62220-1-3:2008. It isidentical to IEC 62220-1-3:2008.The UK participation in its preparation was entrusted by Technical Com
3、mitteeCH/62, Electromedical equipment in medical practice, to SubcommitteeCH/62/2, Diagnostic imaging equipment.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Use
4、rs are responsible for its correct application. BSI 2009ISBN 978 0 580 55495 7ICS 11.040.50BRITISH STANDARDBS EN 62220-1-3:2008Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy C
5、ommittee on 30 April 2009Amendments issued since publicationAmd. No. Date Text affectedLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSIEUROPEAN STANDARD EN 62220-1-3 NORME EUROPENNE EUROPISCHE NORM September 2008 CENELEC European Committee for Elect
6、rotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref.
7、No. EN 62220-1-3:2008 E ICS 11.040.50 English version Medical electrical equipment - Characteristics of digital X-ray imaging devices - Part 1-3: Determination of the detective quantum efficiency - Detectors used in dynamic imaging (IEC 62220-1-3:2008) Appareils lectromdicaux - Caractristiques des d
8、ispositifs dimagerie numrique rayonnement X - Partie 1-3: Dtermination de lefficacit quantique de dtection - Dtecteurs utiliss en imagerie dynamique(CEI 62220-1-3:2008) Medizinische elektrische Gerte - Merkmale digitaler Rntgenbildgerte - Teil 1-3: Bestimmung der detektiven Quanten-Ausbeute - Bildem
9、pfnger fr dynamische Bildgebung (IEC 62220-1-3:2008) This European Standard was approved by CENELEC on 2008-07-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without
10、any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language m
11、ade by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark,
12、 Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/
13、2009 03:51, Uncontrolled Copy, (c) BSIEN 62220-1-3:2008 - 2 - Foreword The text of document 62B/694/FDIS, future edition 1 of IEC 62220-1-3, prepared by SC 62B, Diagnostic imaging equipment, of IEC TC 62, Electrical equipment in medical practice, was submitted to the IEC-CENELEC parallel vote and wa
14、s approved by CENELEC as EN 62220-1-3 on 2008-07-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2009-04-01 latest date by which the national standards conflicting with th
15、e EN have to be withdrawn (dow) 2011-07-01 In this standard, terms printed in SMALL CAPITALS are used as defined in IEC/TR 60788, in Clause 3 of this standard or in other IEC publications referenced in the Index of defined terms. Where a defined term is used as a qualifier in another defined or unde
16、fined term it is not printed in SMALL CAPITALS, unless the concept thus qualified is defined or recognized as a “derived term without definition”. NOTE Attention is drawn to the fact that, in cases where the concept addressed is not strongly confined to the definition given in one of the publication
17、s listed above, a corresponding term is printed in lower-case letters. In this standard, certain terms that are not printed in SMALL CAPITALS have particular meanings, as follows: “shall“ indicates a requirement that is mandatory for compliance; “should“ indicates a strong recommendation that is not
18、 mandatory for compliance; “may“ indicates a permitted manner of complying with a requirement or of avoiding the need to comply; “specific“ is used to indicate definitive information stated in this standard or referenced in other standards, usually concerning particular operating conditions, test ar
19、rangements or values connected with compliance; “specified“ is used to indicate definitive information stated by the manufacturer in accompanying documents or in other documentation relating to the equipment under consideration, usually concerning its intended purposes, or the parameters or conditio
20、ns associated with its use or with testing to determine compliance. This European Standard has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association and covers essential requirements of EC Directive MDD (93/42/EEC). See Annex ZZ. Annexes ZA
21、 and ZZ have been added by CENELEC. _ BS EN 62220-1-3:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSI- 3 - EN 62220-1-3:2008 Endorsement notice The text of the International Standard IEC 62220-1-3:2008 was approved by CENELEC as a European Stan
22、dard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 62220-1 NOTE Harmonized as EN 62220-1:2004 (not modified). IEC 62220-1-2 NOTE Harmonized as EN 62220-1-2:2007 (not modified). IEC 61262-5 NOTE Harmonized as
23、 EN 61262-5:1994 (not modified). _ Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSIEN 62220-1-3:2008 - 4 - Annex ZA (normative) Normative references to international publications with their corresponding European publications The following reference
24、d documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modif
25、ications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60336 -1)Medical electrical equipment - X-ray tube assemblies for medical diagnosis - Characteristics of focal spots EN 60336 20052)IEC/TR 60788 2004 Medical electrical equipment - Glossary of defined ter
26、ms - - IEC 61267 1994 Medical diagnostic X-ray equipment - Radiation conditions for use in the determination of characteristics EN 612673) 1994 ISO 12232 1998 Photography - Electronic still-picture cameras - Determination of ISO speed - - 1)Undated reference. 2)Valid edition at date of issue. 3) IEC
27、 61267:2005 is harmonised as EN 61267:2006 (not modified). BS EN 62220-1-3:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSI- 5 - EN 62220-1-3:2008 Annex ZZ (informative) Coverage of Essential Requirements of EC Directives This European Standard
28、has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association and within its scope the standard covers all relevant essential requirements as given in Annex I of the EC Directive 93/42/EEC Compliance with this standard provides one means of con
29、formity with the specified essential requirements of the Directive concerned. WARNING: Other requirements and other EC Directives may be applicable to the products falling within the scope of this standard. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (
30、c) BSI 2 62220-1-3 IEC:2008 CONTENTS INTRODUCTION.6 1 Scope.7 2 Normative references .7 3 Terms and definitions .8 4 Requirements .10 4.1 Operating conditions .10 4.2 X-RAY EQUIPMENT .10 4.3 RADIATION QUALITY .10 4.4 TEST DEVICE.11 4.5 Geometry 12 4.6 IRRADIATION conditions 14 4.6.1 General conditio
31、ns 14 4.6.2 AIR KERMA measurement 15 4.6.3 LAG EFFECTS.16 4.6.4 IRRADIATION to obtain the CONVERSION FUNCTION 16 4.6.5 IRRADIATION for determination of the NOISE POWER SPECTRUM and LAG EFFECTS .16 4.6.6 IRRADIATION with TEST DEVICE in the RADIATION BEAM.17 4.6.7 Overview of all necessary IRRADIATION
32、S .18 5 Corrections of RAW DATA .18 6 Determination of the DETECTIVE QUANTUM EFFICIENCY 19 6.1 Definition and formula of DQE(u,v) .19 6.2 Parameters to be used for evaluation 19 6.3 Determination of different parameters from the images20 6.3.1 Linearization of data 20 6.3.2 The LAG EFFECTS corrected
33、 NOISE POWER SPECTRUM (NPS) .20 6.3.3 Determination of the MODULATION TRANSFER FUNCTION (MTF)24 7 Format of conformance statement 24 8 Accuracy 25 Annex A (informative) Determination of LAG EFFECTS26 Annex B (informative) Calculation of the input NOISE POWER SPECTRUM 29 Bibliography30 Index of defin
34、ed terms 32 Figure 1 TEST DEVICE .12 Figure 2 Geometry for exposing the DIGITAL X-RAY IMAGING DEVICE in order to determine the CONVERSION FUNCTION, the NOISE POWER SPECTRUM and the MODULATION TRANSFER FUNCTION behind the TEST DEVICE.14 Figure 3 Image acquisition sequence to determine the NOISE POWER
35、 SPECTRUM and LAG EFFECTS17 Figure 4 Geometric arrangement of the ROIs.21 Figure A.1 Power spectral density of white noise s and correlated signal g (only positive frequencies are shown)27 BS EN 62220-1-3:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy,
36、 (c) BSI62220-1-3 IEC:2008 3 Table 1 RADIATION QUALITY (IEC 61267:1994) for the determination of DETECTIVE QUANTUM EFFICIENCY and corresponding parameters .11 Table 2 Necessary IRRADIATIONS 18 Table 3 Parameters mandatory for the application of this standard 20 BS EN 62220-1-3:2008Licensed Copy: Wan
37、g Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSI 6 62220-1-3 IEC:2008 INTRODUCTION DIGITAL X-RAY IMAGING DEVICES are increasingly used in medical diagnosis and will widely replace conventional (analogue) imaging devices such as screen-film systems or analogue X-RAY I
38、MAGE INTENSIFIER television systems in the future. It is necessary, therefore, to define parameters that describe the specific imaging properties of these DIGITAL X-RAY IMAGING DEVICES and to standardize the measurement procedures employed. There is growing consensus in the scientific world that the
39、 DETECTIVE QUANTUM EFFICIENCY (DQE) is the most suitable parameter for describing the imaging performance of an X-ray imaging device. The DQE describes the ability of the imaging device to preserve the signal-to-NOISE ratio from the radiation field to the resulting digital image data. Since in X-ray
40、 imaging, the NOISE in the radiation field is intimately coupled to the AIR KERMA level, DQE values can also be considered to describe the dose efficiency of a given DIGITAL X-RAY IMAGING DEVICE. NOTE 1 In spite of the fact that the DQE is widely used to describe the performance of imaging devices,
41、the connection between this physical parameter and the decision performance of a human observer is not yet completely understood 1, 3.1)NOTE 2 IEC 61262-5 specifies a method to determine the DQE of X-RAY IMAGE INTENSIFIERS at nearly zero SPATIAL FREQUENCY. It focuses only on the electro-optical comp
42、onents of X-RAY IMAGE INTENSIFIERS, not on the imaging properties as this standard does. As a consequence, the output is measured as an optical quantity (luminance), and not as digital data. Moreover, IEC 61262-5 prescribes the use of a RADIATION SOURCE ASSEMBLY, whereas this standard prescribes the
43、 use of an X-RAY TUBE. The scope of IEC 61262-5 is limited to X-RAY IMAGE INTENSIFIERS and does not interfere with the scope of this standard. The DQE is already widely used by manufacturers to describe the performance of their DIGITAL X-RAY IMAGING DEVICE. The specification of the DQE is also requi
44、red by regulatory agencies (such as the Food and Drug Administration (FDA) for admission procedures. However, there is presently no standard governing either the measurement conditions or the measurement procedure, with the consequence that values from different sources may not be comparable. This s
45、tandard has therefore been developed in order to specify the measurement procedure together with the format of the conformance statement for the DETECTIVE QUANTUM EFFICIENCY of DIGITAL X-RAY IMAGING DEVICES. In the DQE calculations proposed in this standard, it is assumed that system response is mea
46、sured for objects that attenuate all energies equally (task-independent) 5. This standard will be beneficial for manufacturers, users, distributors and regulatory agencies. It is the third document out of a series of three related standards: Part 1, which is intended to be used in RADIOGRAPHY, exclu
47、ding MAMMOGRAPHY and RADIOSCOPY. Part 1-2, which is intended to be used for MAMMOGRAPHY. the present Part 1-3, which is intended to be used for dynamic imaging detectors. These standards can be regarded as the first part of the family of IEC 62220 standards describing the relevant parameters of DIGI
48、TAL X-RAY IMAGING DEVICES. 1)Figures in square brackets refer to the bibliography. BS EN 62220-1-3:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/08/2009 03:51, Uncontrolled Copy, (c) BSI62220-1-3 IEC:2008 7 MEDICAL ELECTRICAL EQUIPMENT CHARACTERISTICS OF DIGITAL X-RAY IMAGING DEVICES
49、 Part 1-3: Determination of the detective quantum efficiency Detectors used in dynamic imaging 1 Scope This part of IEC 62220 specifies the method for the determination of the DETECTIVE QUANTUM EFFICIENCY (DQE) of DIGITAL X-RAY IMAGING DEVICES as a function of AIR KERMA and of SPATIAL FREQUENCY for the working conditions in the range of the medical application as specified by the MANUFACTURER. The intended users of this part of IEC 62220 are man
