1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Part 2-6: Constancy tests Imaging performance of computed tomography X-ray equipmentThe European St
2、andard EN 61223-2-6:2007 has the status of a British StandardICS 11.040.50Evaluation and routine testing in medical imaging departments BRITISH STANDARDBS EN 61223-2-6:2007BS EN 61223-2-6:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30
3、 November 2007 BSI 2007ISBN 978 0 580 54783 6Amendments issued since publicationAmd. No. Date Commentsrequest to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard
4、 cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of EN 61223-2-6:2007. It is identical to IEC 61223-2-6:2006. It supersedes BS EN 61223-2.6:1995 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committ
5、ee CH/62, Electromedical equipment in medical practice, to Subcommittee CH/62/2, Diagnostic imaging equipment.A list of organizations represented on this committee can be obtained on EUROPEAN STANDARD EN 61223-2-6 NORME EUROPENNE EUROPISCHE NORM May 2007 CENELEC European Committee for Electrotechnic
6、al Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61
7、223-2-6:2007 E ICS 11.040.50 Supersedes EN 61223-2-6:1994English version Evaluation and routine testing in medical imaging departments - Part 2-6: Constancy tests - Imaging performance of computed tomography X-ray equipment (IEC 61223-2-6:2006) Essais dvaluation et de routine dans les services dimag
8、erie mdicale - Partie 2-6: Essais de constance - Performance dimagerie des quipements de tomodensitomtrie rayonnement X (CEI 61223-2-6:2006) Bewertung und routinemige Prfung in Abteilungen fr medizinische Bildgebung - Teil 2-6: Konstanzprfungen - Rntgeneinrichtungen fr die Computertomographie (IEC 6
9、1223-2-6:2006) This European Standard was approved by CENELEC on 2007-03-01. 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 any alteration. Up-to-date lists and b
10、ibliographical 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 made by translation under the responsib
11、ility 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, Estonia, Finland, France, Germany, Gr
12、eece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 61223-2-6:2007 2 Foreword The text of document 62B/629/FDIS, future edition 2 of IEC 61223-2-6,
13、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 was approved by CENELEC as EN 61223-2-6 on 2007-03-01. This European Standard supersedes EN 61223-2-6:1994. EN 61223-2-6:2007 is harmonized wit
14、h the content of EN 60601-2-44:2001 + A1:2003 and with EN 61223-3-5:2004. Instead of harmonizing test procedures for all modalities of X-ray equipment, as intended in EN 61223-2-6:1994, this EN 61223-2-6:2007 comprises part of a set of standards covering all of the particular requirements for CT sca
15、nners. 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) 2007-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-03-01 In
16、this standard, the following print types are used: requirements, compliance with which can be tested, and definitions: in roman type; explanations, advice, notes, general statements, exceptions and references: in smaller type; test specifications: in italic type; TERMS DEFINED IN EN 60601-1, IN EN 6
17、0788, IN EN 61223-1 OR IN OTHER PUBLICATIONS REFERENCED IN THE INDEX OF DEFINED TERMS: SMALL CAPITALS. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61223-2-6:2006 was approved by CENELEC as a European Standard without any modification. _ 3 EN 61
18、223-2-6:2007 CONTENTS INTRODUCTION.4 1 Scope and object5 2 Normative references .5 3 Terms and definitions .6 4 General aspects of CONSTANCY TESTS10 4.1 Preconditions 10 4.2 General conditions affecting test procedures 10 4.3 Establishment of BASELINE VALUES 11 4.4 Identification of equipment, instr
19、umentation and test conditions11 4.5 Scope of the CONSTANCY TESTS 12 4.6 Test equipment, including PHANTOMS and TEST DEVICES.12 4.7 Frequency of CONSTANCY TESTS13 5 Test methods for CT SCANNERS .13 5.1 Positioning of the PATIENT SUPPORT 13 5.2 PATIENT positioning accuracy14 5.3 TOMOGRAPHIC SECTION T
20、HICKNESS .16 5.4 Dose .18 5.5 NOISE, UNIFORMITY AND MEAN CT NUMBERS .19 5.6 SPATIAL RESOLUTION .21 Annex A (informative) Guidance on action to be taken 23 Annex B (informative) Alternate test methods for SPATIAL RESOLUTION .25 Annex C (informative) TOMOGRAPHIC SECTION THICKNESS for helical scanning.
21、28 Annex D (informative) Visual method for LOW CONTRAST RESOLUTION .29 Annex ZA (normative) Normative references to international publications with their corresponding European publications34 Bibliography .30 Index of terms.32 Figure 1 Coordinate system used for CT SCANNERS.10 Table B.1 Comparison o
22、f SPATIAL RESOLUTION test procedures 25 EN 61223-2-6:2007 4 INTRODUCTION The second edition of this standard is harmonized with the content of IEC 60601-2-44:2001, Particular requirements for the safety of X-ray equipment for computed tomography and its Amendment 1 (2002), and IEC 61223-3-5, Evaluat
23、ion and routine testing in medical imaging departments Part 3-5, Acceptance tests Imaging performance of computed tomography X-ray equipment. In case the CT SCANNER does not offer an integrated, automated evaluation of the test images, attention shall be given to the proper function and setting of t
24、he IMAGE DISPLAY DEVICE. It is strongly recommended to assure its proper functioning prior to the constancy testing of the CT SCANNER, applying IEC 61223-2-5 1)1on IMAGE DISPLAY DEVICES or the related in-house procedure. Some provisions or statements in this standard require additional information,
25、which is presented in the annexes. An asterisk in the left margin of a clause or subclause indicates the presence of such additional information. With regard to the measurements, reference is made to methods described in related publications, which for practical reasons should be carried out prior t
26、o the application of the methods described in this standard. This standard forms Part 2-6 of IEC 61223, which includes the following parts of particular interest in the context of this standard: Part 1: General aspects 2Part 2-4: Constancy tests Hard copy cameras 3 Part 2-5: Constancy tests Image di
27、splay devices 1)Figures in square brackets refer to the Bibliography. 5 EN 61223-2-6:2007 EVALUATION AND ROUTINE TESTING IN MEDICAL IMAGING DEPARTMENTS Part 2-6: Constancy tests Imaging performance of computed tomography X-ray equipment 1 Scope and object This part of IEC 61223 provides assistance i
28、n performing CONSTANCY TESTS on a CT SCANNER. It applies to those components of CT SCANNERS which influence the image quality, PATIENT dose and positioning. This standard defines the essential parameters which describe the performance of CT SCANNERS with regard to image quality, PATIENT dose and pos
29、itioning; the list of parameters to be tested can be found in section 4.5; defines the methods of testing the essential parameters; provides criteria to be applied in the evaluation of data for compliance with the tolerances of the parameters specified by the ACCOMPANYING DOCUMENTS and with respect
30、to BASELINE VALUES. These methods rely on non-invasive measurements, using appropriate test equipment, performed to ensure that the functional performance of EQUIPMENT meets ESTABLISHED CRITERIA or to enable the early recognition of changes in the properties of components of the EQUIPMENT. The aim i
31、s to verify compliance with specifications affecting the image quality, PATIENT dose and PATIENT positioning. It is not intended to consider: aspects of mechanical and electrical safety nor aspects of mechanical, electrical and software performance, unless they are essential for performing the CONST
32、ANCY TESTS and directly affect image quality, PATIENT dose and positioning. 2 Normative references The following referenced 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 refere
33、nced document (including any amendments) applies. IEC 60788:2004, Medical electrical equipment Glossary of defined terms IEC 61223-3-5:2004, Evaluation and routine testing in medical imaging departments Part 3-5: Acceptance tests Imaging performance of computed tomography X-ray equipment EN 61223-2-
34、6:2007 6 IEC 60601-2-44:2001, Medical electrical equipment Part 2-44: Particular requirements for the safety of X-ray equipment for computed tomography Amendment 1 (2002) 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60788:2004 and the following ap
35、ply. NOTE 1 An index of defined terms used in this standard is given following the annexes NOTE 2 Attention is drawn to the fact that in cases where the concept addressed is not strongly confined to the definition given in IEC 61223-1 or IEC 60788, a corresponding term is printed in lower case lette
36、rs. 3.1 CT CONDITIONS OF OPERATION all selectable parameters governing the operation of a CT SCANNER, for example NOMINAL TOMOGRAPHIC SECTION THICKNESS, CT PITCH FACTOR, FILTRATION, peak X-RAY TUBE VOLTAGE and either X-RAY TUBE CURRENT and LOADING TIME or CURRENT TIME PRODUCT IEC 60601-2-44:2001, de
37、finition 2.102 3.2 CT SCANNER X-RAY EQUIPMENT for COMPUTED TOMOGRAPHY (CT) diagnostic X-ray system intended to generate cross-sectional images of the body by computer reconstruction of X-ray transmission data obtained at different angles. This generic type of device may include signal analysis and d
38、isplay equipment, PATIENT SUPPORT, support parts and accessories NOTE Secondary imaging processing is not included in the scope of this standard. IEC 60601-2-44, Amend.1:2002, definition 2.101 3.3 COMPUTED TOMOGRAPHY DOSE INDEX 100 CTDI100integral of the DOSE PROFILE produced in a single axial scan
39、along a line perpendicular to the TOMOGRAPHIC PLANE from 50 mm to + 50 mm, divided by the product of the number of TOMOGRAPHIC SECTIONS N and the NOMINAL TOMOGRAPHIC SECTION THICKNESS T dz T N(z) D+-mm 50mm 50= CTDI100where D(z) is the DOSE PROFILE along a line z perpendicular to the TOMOGRAPHIC PLA
40、NE, where dose is reported as ABSORBED DOSE to air; N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of the X-ray source; T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS. NOTE 1 The term CTDI100has been introduced as a more representative value for dose than the traditional CTD
41、I integrated from 7 T to + 7 T as defined by the FDA in 21 CFR 1020.33 31. NOTE 2 The dose is reported as ABSORBED DOSE to air. This is required in order to avoid present confusion, as some MANUFACTURERS of CT SCANNERS express dose values calculated as ABSORBED DOSE to air and others as ABSORBED DOS
42、E to polymethyl-methacrylate (PMMA). 7 EN 61223-2-6:2007 Although CTDI100refers to ABSORBED DOSE to air, for practical purposes the evaluation of ABSORBED DOSE to air within a PMMA dosimetry PHANTOM is well approximated by measurement of the AIR KERMA with an ionization chamber in the PHANTOM. NOTE
43、3 This definition assumes that the DOSE PROFILE is centred on z = 0. NOTE 4 A single axial scan is typically a 360 rotation of the X-ray source. IEC 60601-2-44, Amendment 1:2002, definition 2.106 3.4 WEIGHTED CTDI100 The WEIGHTED CTDI100(CTDIw) is defined as )ral 00(periphe1) 100(centreW3231CTDICTDI
44、CTDI += where CTDI100(centre)is the value measured in the centre of the CT DOSIMETRY PHANTOM and CTDI100(peripheral)is the average value measured in the periphery of the CT DOSIMETRY PHANTOM 3.5 COMPUTED TOMOGRAPHY NUMBER (CT NUMBER) number used to represent the mean X-ray ATTENUATION associated wit
45、h each elemental area of the COMPUTED TOMOGRAPHY image NOTE The CT NUMBER is normally expressed in Hounsfield units. MEASURED VALUES of the linear ATTENUATION coefficients are transformed into CT NUMBERS using the international Hounsfield scale, using the expression: 0001waterwatermaterial=materialo
46、fnumberCT where is the linear ATTENUATION coefficient. The CT NUMBER scale is defined so that water has a value of 0 and air a value of -1000 (airis assumed to be 0). 3.6 COMPUTED TOMOGRAPHY DOSE INDEX FREE IN AIR CTDIfree airCTDI100measured at isocentre in the absence of a PHANTOM and the PATIENT S
47、UPPORT 3.7 CT PITCH FACTOR in helical scanning the ratio of the PATIENT SUPPORT travel d along the z direction per rotation of the X-RAY SOURCE divided by the product of the NOMINAL TOMOGRAPHIC SECTION THICKNESS T and the number of TOMOGRAPHIC SECTIONS N: N Tdfactor=pitchCT where d is the PATIENT SU
48、PPORT travel along the z direction per rotation of the X-RAY SOURCE; T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS; EN 61223-2-6:2007 8 N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of the X-RAY SOURCE. IEC 60601-2-44, Amend.1:2002, definition 2.107 3.8 DOSE PROFILE repres
49、entation of the dose as a function of position along a line. IEC 60601-2-44:2001, definition 2.103 3.9 MEAN CT NUMBER mean value of the CT NUMBERS of all pixels within a certain defined REGION OF INTEREST 3.10 NOISE variation of CT NUMBERS from a mean value in a defined area in the image of a uniform substance NOTE The magnitude of NOISE is indicated by the standard deviation of the CT
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