1、 INTERNATIONAL STANDARD IECCEINORME INTERNATIONALE62220-1-2First editionPremire dition2007-06Medical electrical equipment Characteristics of digital X-ray imaging devices Part 1-2: Determination of the detective quantum efficiency Detectors used in mammography Appareils lectromdicaux Caractristiques
2、 des dispositifs dimagerie numrique rayonnement X Partie 1-2: Dtermination de lefficacit quantique de dtection Dtecteurs utiliss en mammographie Reference number Numro de rfrence IEC/CEI 62220-1-2:2007 THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2007 IEC, Geneva, Switzerland All rights reserve
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15、ME INTERNATIONALE62220-1-2First editionPremire dition2007-06Medical electrical equipment Characteristics of digital X-ray imaging devices Part 1-2: Determination of the detective quantum efficiency Detectors used in mammography Appareils lectromdicaux Caractristiques des dispositifs dimagerie numriq
16、ue rayonnement X Partie 1-2: Dtermination de lefficacit quantique de dtection Dtecteurs utiliss en mammographie U Commission Electrotechnique InternationaleInternational Electrotechnical Commission PRICE CODE CODE PRIX For price, see current cataloguePour prix, voir catalogue en vigueur 2 62220-1-2
17、IEC:2007 CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.6 2 Normative references .6 3 Terminology and definitions7 4 Requirements .9 4.1 Operating conditions .9 4.2 X-RAY EQUIPMENT .9 4.3 RADIATION QUALITY .9 4.4 TEST DEVICE .10 4.5 Geometry 11 4.6 IRRADIATION conditions.12 5 Corrections of RAW DATA .15
18、 6 Determination of the DETECTIVE QUANTUM EFFICIENCY.16 6.1 Definition and formula of DQE(u,v) 16 6.2 Parameters to be used for evaluation 16 6.3 Determination of different parameters from the images17 7 Format of conformance statement 21 8 Accuracy 21 Annex A (normative) Determination of LAG EFFECT
19、S22 Annex B (informative) Calculation of the input NOISE POWER SPECTRUM.25 Bibliography26 Terminology Index of defined terms .28 62220-1-2 IEC:2007 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ MEDICAL ELECTRICAL EQUIPMENT CHARACTERISTICS OF DIGITAL X-RAY IMAGING DEVICES Part 1-2: Determination of t
20、he detective quantum efficiency Detectors used in mammography FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international c
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30、cation may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 62220-1-2 has been prepared by subcommittee 62B: Diagnostic imaging equipment, of IEC technical committee 62: Electrical equipment in medical practi
31、ce. The text of this standard is based on the following documents: FDIS Report on voting 62B/649/FDIS 62B/656/RVDFull information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with th
32、e ISO/IEC Directives, Part 2. 4 62220-1-2 IEC:2007 A list of all parts of the IEC 62220 series, published under the general title Medical electrical equipment Characteristics of digital X-ray imaging devices, can be found on the IEC website. In this standard, terms printed in SMALL CAPITALS are used
33、 as defined in IEC 60788, in Clause 3 of this standard or other IEC publications referenced in the Index of defined terms. Where a defined term is used as a qualifier in another defined or undefined term it is not printed in SMALL CAPITALS, unless the concept thus qualified is defined or recognized
34、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 publications listed above, a corresponding term is printed in lower-case letters. In this standard, certain terms that
35、 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 mandatory for compliance; “may“ indicates a permitted manner of complying with a requirement or of avoidin
36、g 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 arrangements or values connected with compliance; “specified“ is used to indicate definitive information stat
37、ed 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 conditions associated with its use or with testing to determine compliance. The committee has decided that the cont
38、ents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. 62220
39、-1-2 IEC:2007 5 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 IMAGE INTENSIFIER television systems in the future. It is necessary, therefore, to defin
40、e 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 DETECTIVE QUANTUM EFFICIENCY (DQE) is the most suitable parameter for describing the i
41、maging 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 imaging, the NOISE in the radiation field is intimately coupled to the AIR KERMA level
42、, DQE values can also be considered to describe the dose efficiency of a given DIGITAL X-RAY IMAGING DEVICE. NOTE In spite of the fact that the DQE is widely used to describe the performance of imaging devices, the connection between this physical parameter and the decision performance of a human ob
43、server is not yet completely understood 1, 3.1)The DQE is already widely used by manufacturers to describe the performance of their DIGITAL X-RAY IMAGING DEVICES. The specification of the DQE is also required by regulatory agencies (such as the Food and Drug Administration (FDA) for admission proced
44、ures. 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 standard has therefore been developed in order to specify the measurement procedure together with
45、 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 measured for objects that attenuate all energies equally (task-independent) 5. This standard will b
46、e beneficial for manufacturers, users, distributors and regulatory agencies. It is the second document out of a series of three related standards: Part 1, which is intended to be used in RADIOGRAPHY, excluding MAMMOGRAPHY and RADIOSCOPY; the present Part 1-2, which is intended to be used for MAMMOGR
47、APHY; 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 62220 standards describing the relevant parameters of DIGITAL X-RAY IMAGING DEVICES. 1)Figures in square brackets refer to the bibliography. 6 62220-1-2 IEC:
48、2007 MEDICAL ELECTRICAL EQUIPMENT CHARACTERISTICS OF DIGITAL X-RAY IMAGING DEVICES Part 1-2: Determination of the detective quantum efficiency Detectors used in mammography 1 Scope This part of IEC 62220 specifies the method for the determination of the DETECTIVE QUANTUM EFFICIENCY (DQE) of DIGITAL
49、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 manufacturers and well equipped test laboratories. This Part 1-2 is restricted to DIGITAL X-RAY IMAGING
