1、BRITISH STANDARD BS EN 61953:1998 IEC 61953: 1997 Diagnostic X-ray imaging equipment Characteristics of mammographic anti-scatter grids The European Standard EN 61953:1997 has the status of a British Standard ICS 11.040.50BSEN61953:1998 This British Standard, having been prepared under the direction
2、 of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15April1998 BSI 05-1999 ISBN 0 580 28451 4 Amendments issued since publication Amd. No. Date CommentsBSEN61953:1998 BSI05-1999 i Contents Page National foreword ii Foreword
3、2 Text of EN 61953 3BSEN61953:1998 ii BSI05-1999 National foreword This British Standard is the English language version of EN61953:1998. It is identical with IEC61953:1997. The UK participation in its preparation was entrusted to Technical Committee CH/73, Radiation protection dose control and util
4、ization, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and pr
5、omulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC60027-1. For a period of time during th
6、e change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references Attention is drawn to the fact that CEN and CENELEC standards normally include an annex which lists normative references to international publications with their correspondi
7、ng European publications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standa
8、rds Electronic Catalogue. Additional information. The following print types are used in this standard. Requirements, with which compliance can be tested, and definitions: in roman type. Explanations, advice, general statements, exceptions and references: in small roman type. Test procedures: in ital
9、ic type. Terms defined in BS5724-1 or in BS6641: SMALL CAPITALS. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity
10、from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 18 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendm
11、ent table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61953 January 1998 ICS 11.040.50 English version Diagnostic X-ray imaging equipment Characteristics of mammographic anti-scatter grids (IEC 61953:1997) Appareils dimagerie de diagnostic rayonnement X Caractristi
12、ques des grilles antidiffusantes pour la mammographie (CEI 61953:1997) Bildgebende Gerte fr die Rntgendiagnostik Kenngren von Streustrahler-Rastern fr die Mammographie (IEC61953:1997) This European Standard was approved by CENELEC on 1997-07-01. CENELEC members are bound to comply with the CEN/CENEL
13、EC 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 bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CE
14、NELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made 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 version
15、s. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotec
16、hnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1998 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61
17、953:1998 EEN61953:1998 BSI05-1999 2 Foreword The text of document 62B/297/FDIS, future edition1 of IEC61953, prepared by SC 62B, Diagnostic imaging equipment, of IECTC62, Electrical equipment in medical practice, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN61953 o
18、n1997-07-01. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In this standard, Annex A, Annex B and Annex ZA are normative and Annex C is informative. Annex ZA has been added by CENE
19、LEC. Endorsement notice The text of the International Standard IEC61953:1997 was approved by CENELEC as a European Standard without any modification. Contents Page Foreword 2 Introduction 3 1 Scope and object 3 2 Normative references 3 3 Terminology 4 3.1 Degree of requirements 4 3.2 Use of terms 4
20、3.3 Defined terms 4 4 Structure of MAMMOGRAPHIC ANTI-SCATTER GRIDS 6 5 Measurement and determination of physical characteristics 7 5.1 Method and arrangement for measurement 7 5.2 Physical characteristics 8 6 Requirements for MAMMOGRAPHIC ANTI-SCATTER GRIDS 9 6.1 Manufacturing tolerances 9 6.2 Deter
21、mination of the APPLICATION LIMITS 9 6.3 Accuracy of characteristics 9 6.4 Marking and ACCOMPANYING DOCUMENTS 10 6.5 Statement of compliance 11 Annex A (normative) Calculation of the APPLICATION LIMITS 15 Annex B (normative) Terminology Index of defined terms 15 Annex C (informative) Bibliography 17
22、 Annex ZA (normative) Normative references to international publications with their corresponding European publications 18 Figure 1 Structure of MAMMOGRAPHIC ANTI-SCATTER GRIDS 11 Figure 2 RADIATION DETECTOR 12 Figure 3 Measurement arrangement for MAMMOGRAPHIC ANTI-SCATTER GRIDS with NARROW BEAM CON
23、DITION 13 Figure 4 Measurement arrangement for MAMMOGRAPHIC ANTI-SCATTER GRIDS with BROAD BEAM CONDITION 14 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1998-07-01 latest date by which the national standa
24、rds conflicting with the EN have to be withdrawn (dow) 1998-07-01EN61953:1998 BSI05-1999 3 Introduction X-ray mammography is an examination which is technically demanding because of the need to achieve high contrast and excellent resolution whilst limiting the absorbed dose to the female breast. Low
25、 energy X-rays, compression and a special geometry are needed to achieve these objectives. Therefore, only dedicated X-RAY EQUIPMENT should be used. While most of such equipment incorporates an ANTI-SCATTER GRID, the MAMMOGRAPHIC ANTI-SCATTER GRIDS used are not covered by IEC60627. ANTI-SCATTER GRID
26、S used in general radiology are covered by IEC 60627, and this standard follows the same outline. During the writing of this standard, it became clear that a revision of IEC 60627 was necessary, and work on this has started. It is intended that the two standards covering ANTI-SCATTER GRIDS will be m
27、erged together. To facilitate this, some subclauses are not used here and extra subclauses have been introduced. Some of the differences between IEC 60627 and this standard are outlined below. The concept of a reference grid is now omitted. It was found that such grids were little used. It should be
28、 sufficient to unambiguously define the RADIATION DETECTOR and procedure. The geometry used here simulates a typical mammography examination. Only one PHANTOM is used for measurements of TRANSMISSION OF PRIMARY RADIATION and TRANSMISSION OF SCATTERED RADIATION. The FLUORESCENT SCREEN used for the me
29、asurements employs a thinner calcium tungstate phosphor. This is not a standard mammography phosphor, but this material is well defined, resulting in better uniformity of performance between different screens. The APPLICATION LIMITS needed to be reduced for mammography. The production tolerances hav
30、e been narrowed, compared to the grids used in general radiology, in order to have meaningful characteristic data which allow the distinction between different grid types used in mammography. Consequently, the measuring tolerances have also been narrowed. Special laboratory equipment and carefully c
31、ontrolled test conditions are needed for the measurements described here. 1 Scope and object This International Standard deals with the definitions, determinations and indication of characteristics of MAMMOGRAPHIC ANTI-SCATTER grids used in diagnostic X-ray imaging equipment, in order to reduce the
32、incidence of SCATTERED RADIATION, produced particularly in the body of the PATIENT, upon the IMAGE RECEPTION area and thus to improve the contrast of the X-RAY PATTERN. At present only focused ANTI-SCATTER grids are used in mammography. The scope of this standard is therefore restricted to FOCUSED G
33、RIDS. This standard is not intended to be applied for ACCEPTANCE TESTS. This standard does not cover the homogeneity of performance over the area of a grid. This standard is not intended to be applied for the determination of the characteristics of MAMMOGRAPHIC ANTI-SCATTER GRIDS under conditions wh
34、ich can normally be found in installations of X-RAY EQUIPMENT at the USERS site. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated
35、 were valid. All normative documents are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents listed below. Members of IEC and ISO maintain registers of curren
36、tly valid International Standards. IEC 60417:1973, Graphical symbols for use on equipment. Index, survey and compilation of the single sheets. IEC 60417N:(1995), Thirteenth supplement. EN61953:1998 4 BSI05-1999 IEC 60601-1:1988, Medical electrical equipment Part 1: General requirements for safety. A
37、mendment 1 (1991) Amendment 2 (1995) IEC 60627:1978, Characteristics of anti-scatter grids used in X-ray equipment. IEC 60788:1984, Medical radiology Terminology. IEC 61223-1:1993, Evaluation and routine testing in medical imaging departments Part 1: General aspects. IEC 61267:1994, Medical diagnost
38、ic X-ray equipment Radiation conditions for use in the determination of characteristics. 3 Terminology 3.1 degree of requirements in this standard, certain terms which are not printed in SMALL CAPITALS have particular meanings, as follows: 3.2 use of terms in this standard, terms printed in SMALL CA
39、PITALS are used as defined in IEC60601-1, in IEC60788, in clause3 of this standard or in other standards referenced in Annex B 3.3 Defined terms For the purpose of this International Standard, the following definitions apply. NOTESome of the defined terms given in this standard deviate from those gi
40、ven in the current edition (1984) of IEC 60788. 3.3.1 ANTI-SCATTER GRID device with a fixed periodic arrangement of materials with different X-ray ATTENUATION properties to be placed in front of the IMAGE RECEPTION AREA in order to reduce the incidence of SCATTERED RADIATION upon that area and thus
41、increase the contrast in the X-RAY PATTERN 3.3.2 LINEAR GRID ANTI-SCATTER GRID composed of highly absorbing strips and highly transmitting interspaces which are parallel in their longitudinal direction 3.3.3 not used 3.3.4 FOCUSED GRID LINEAR GRID in which the planes of the absorbing strips converge
42、 to a straight line at the FOCUSING DISTANCE “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 avoiding the need to comply; “speci
43、fic” 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 stated by the MANUFACTURER in AC
44、COMPANYING 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.EN61953:1998 BSI05-1999 5 3.3.5 not used 3.3.6 not used 3.3.7 STATIO
45、NARY GRID ANTI-SCATTER GRID used in such a way that it does not move in relation to the RADIATION BEAM 3.3.8 MOVING GRID ANTI-SCATTER GRID used in an ACCESSORY that enables the ANTI-SCATTER GRID to be moved, when irradiated by a RADIATION BEAM, in order to avoid the imaging of the absorbing strips a
46、nd the consequent loss of information 3.3.9 MAMMOGRAPHIC ANTI-SCATTER GRID FOCUSED GRID specially designed for mammography 3.3.10 Geometric characteristics 3.3.10.1 STRIP FREQUENCY letter symbol: N, unit: cm 1 . Number of absorbing strips per unit length of a LINEAR GRID NOTEThis term replaces the p
47、revious term “STRIPS PER CENTIMETRE”. 3.3.10.2 GRID RATIO letter symbol: r. Ratio between the height of the absorbing strips and the distance between the absorbing strips in the centre of a LINEAR GRID 3.3.10.3 FOCUSING DISTANCE letter symbol: f 0,unit: cm. Distance between the incident face of a FO
48、CUSED GRID and the line into which the planes of the absorbing strips of the grid converge NOTEAttention is drawn to the differences between “FOCUSING DISTANCE”, “FOCAL SPOT to grid distance” and “FOCAL SPOT to film distance”. 3.3.10.4 APPLICATION LIMITS letter symbols: f 1 , f 2 , unit: cm. Lower,
49、f 1 , and upper, f 2 , limits of the distance from the FOCAL SPOT to the incident face of a FOCUSED GRID between which the obtained radiological information can generally be expected to be acceptable 3.3.10.5 TRUE CENTRAL LINE perpendicular projection onto the incident face of a FOCUSED GRID of the line into which the planes of the absorbing strips converge 3.3.10.6 CENTRAL LINE INDICATION on the incident face of a FOCUSED GRID, marking which is intended to indicate the position and direction of the TRU
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