1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationUltrasonics Pulse-echo scannersPart 2: Measurement of maximum depth of penetration and local dynamic rangeBS EN 61391-2:2010National forewordThis British Standard is the UK imple
2、mentation of EN 61391-2:2010. It isidentical to IEC 61391-2:2010.The UK participation in its preparation was entrusted to Technical CommitteeEPL/87, Ultrasonics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to inclu
3、de all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2010ISBN 978 0 580 58266 0ICS 17.140.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy a
4、nd Strategy Committee on 31 July 2010.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 61391-2:2010EUROPEAN STANDARD EN 61391-2 NORME EUROPENNE EUROPISCHE NORM April 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation
5、 Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61391-2:2010 E ICS 17.140.50 English version Ultrasonic
6、s - Pulse-echo scanners - Part 2: Measurement of maximum depth of penetration and local dynamic range (IEC 61391-2:2010) Ultrasons - Scanners impulsion et cho - Partie 2 : Mesure de la profondeur maximale de pntration et de la plage dynamique locale (CEI 61391-2:2010) Ultraschall - Impuls-Echo-Scann
7、er - Teil 2: Messung der maximalen Eindringtiefe und des lokalen Dynamikbereichs (IEC 61391-2:2010) This European Standard was approved by CENELEC on 2010-04-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Stan
8、dard 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 CENELEC member. This European Standard exists in three official versions (English, Fre
9、nch, 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 versions. CENELEC members are the national electrotechnical committees of Austria, Belgium,
10、 Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, 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. BS EN
11、 61391-2:2010EN 61391-2:2010 - 2 - Foreword The text of document 87/400/CDV, future edition 1 of IEC 61391-2, prepared by IEC TC 87, Ultrasonics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61391-2 on 2010-04-01. Attention is drawn to the possibility that some of
12、 the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national
13、 standard or by endorsement (dop) 2011-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-04-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61391-2:2010 was approved by CENELEC as a Europea
14、n Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60601-1:2005 NOTE Harmonized as EN 60601-1:2006 (not modified). IEC 61161:1992 NOTE Harmonized as EN 61161:1994 (not modified). _ BS EN 61391-2:2010-
15、3 - EN 61391-2:2010 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refe
16、rences, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 61391-1 2006 Ultrasonics - Pulse-echo scan
17、ners - Part 1: Techniques for calibrating spatial measurement systems and measurement of system point spread function response EN 61391-1 2006 IEC 62127-1 2007 Ultrasonics - Hydrophones - Part 1: Measurement and characterization of medical ultrasonic fields up to 40 MHz EN 62127-1 2007 BS EN 61391-2
18、:2010 2 61391-2 IEC:2010(E) CONTENTS INTRODUCTION.61 Scope.82 Normative references .83 Terms and definitions .84 General requirement.135 Environmental conditions136 Equipment and data required146.1 General .146.2 Phantoms146.2.1 Phantoms required 146.2.2 Phantom for maximum depth of penetration.146.
19、2.3 Phantoms to estimate local dynamic range 156.3 Test equipment for measuring local dynamic range .156.4 Digitized image data177 Measurement methods .197.1 System sensitivity: maximum depth of penetration.197.1.1 Scanning system settings 197.1.2 Image acquisition 197.1.3 Analysis.207.2 Local dynam
20、ic range .227.2.1 Scanning system settings 227.2.2 Measurement method 227.2.3 Type II testing for measuring local dynamic range .237.2.4 Estimating local dynamic range using backscatter contrast24Annex A (informative) Phantom for determining maximum depth of penetration .26Annex B (informative) Loca
21、l dynamic range using acoustical test objects.28Bibliography35Figure 1 Arrangement for measuring local dynamic range using an acoustic-signal injection technique16Figure 2 Arrangement for measuring local dynamic range using an acoustically-coupled burst generator 17Figure 3 Image of the penetration
22、phantom20Figure 4 Mean digitized image data value vs. depth for the phantom image data (A(j) and for the noise image data (A(j) 21Figure 5 Digitized-image data vs. attenuator setting during local dynamic range measurements using acoustic signal injection.23Figure 6 Image of phantom with inclusions (
23、circles) .24Figure 7 Ensemble-average mean pixel value vs. backscatter contrast of inclusions25Figure A.1 Phantom for maximum depth of penetration tests26Figure B.1 Possible arrangement of reflectors for determining local dynamic range .29Figure B.2 Displayed intensity (or image pixel value) vs. ref
24、lector reflection coefficient .30Figure B.3 Flat ended wire test object for determining local dynamic range32BS EN 61391-2:201061391-2 IEC:2010(E) 3 Figure B.4 The experimentally observed backscattering cross section of flat-ended stainless-steel wires as a function of diameter for three frequencies
25、: U 9.6 MHz; :4.8 MHz; : 2.4 MHz 33.33BS EN 61391-2:2010 6 61391-2 IEC:2010(E) INTRODUCTION An ultrasonic pulse-echo scanner produces images of tissue in a scan plane by sweeping a narrow pulsed beam of ultrasound through the section of interest and detecting the echoes generated by reflection at ti
26、ssue boundaries and by scattering within tissues. Various transducer types are employed to operate in a transmit/receive mode to generate/detect the ultrasonic signals. Ultrasonic scanners are widely used in medical practice to produce images of soft-tissue organs throughout the human body. This sta
27、ndard is being published in two or more parts: Part 1 deals with techniques for calibrating spatial measurement systems and measurement of system point spread function response; Part 2 deals with measurement of system sensitivity (maximum depth of penetration) and local dynamic range. This standard
28、describes test procedures for measuring the maximum depth of penetrationand the local dynamic range of these imaging systems. Procedures should be widely acceptable and valid for a wide range of types of equipment. Manufacturers should use the standard to prepare their specifications; users should e
29、mploy the standard to check performance against those specifications. The measurements can be carried out without interfering with the normal working conditions of the machine. Typical phantoms are described in Annex A. The structures of the phantoms are not specified in detail; instead, suitable ty
30、pes of overall and internal structures for phantoms are described. Similar commercial versions of these test objects are available. The specific structure of a test object selected by the user should be reported with the results obtained when using it. The performance parameters described herein and
31、 the corresponding methods of measurement have been chosen to provide a basis for comparison between similar types of apparatus of different makes but intended for the same kind of diagnostic application. The manufacturers specifications of maximum depth of penetration and local dynamic rangemust al
32、low comparison with the results obtained from the tests described in this standard. It is intended that the sets of results and values obtained from the use of the recommended methods will provide useful criteria for predicting performance with respect to these parameters for equipment operating in
33、the 1 MHz to 15 MHz frequency range. However, availability and some specifications of test objects, such that they are similar to tissue in vivo, are still under study for the frequency range 10 MHz to15 MHz. The procedures recommended in this standard are in accordance with IEC 60601-1 1 and IEC 61
34、391-1. Where a diagnostic system accommodates more than one option in respect of a particular system component, for example the transducer, it is intended that each option be regarded as a separate system. However, it is considered that the performance of a machine for a specific task is adequately
35、specified if measurements are undertaken for the most significant combinations of machine control settings and accessories. Further evaluation of equipment is obviously possible but this should be considered as a special case rather than a routine requirement. The paradigm used for the framework of
36、this standard is to consider the ultrasound imaging system to be composed architecturally of a front-end (generally consisting of the ultrasound transducer, amplifiers, digitizers and beamformer), a back-end (generally consisting of signal conditioning, image formation, image processing and scan con
37、version) and a display (generally consisting of a video monitor but also including any other output device). Under ideal conditions it would be possible for users to test performance of these components of the system independently. It is recognized, however, that some systems and lack of some labora
38、tory resources might prevent this full range of measurements. Thus, the specifications and measurement methods described in this standard refer to image data that are provided in BS EN 61391-2:201061391-2 IEC:2010(E) 7 a digitalized format by the ultrasound machine and that can be accessed by users.
39、 Some scanners do not provide access to digitized image data. For this group of scanners, tests can be done by utilizing frame grabbers to record images. Data can then be analyzed in a computer in the same manner as for image data provided directly by the scanner. BS EN 61391-2:2010 8 61391-2 IEC:20
40、10(E) ULTRASONICS PULSE-ECHO SCANNERS Part 2: Measurement of maximum depth of penetration and local dynamic range 1 Scope This part of IEC 61391 defines terms and specifies methods for measuring the maximum depth of penetration and the local dynamic range of real-time ultrasound B-MODE scanners. The
41、 types of transducers used with these scanners include: mechanical probes; electronic phased arrays; linear arrays; curved arrays; two-dimensional arrays; three-dimensional scanning probes based on a combination of the above types. All scanners considered are based on pulse-echo techniques. The test
42、 methodology is applicable for transducers operating in the 1 MHz to 15 MHz frequency range operating both in fundamental mode and in harmonic modes that extend to 15 MHz. However, testing of harmonic modes above 15 MHz is not covered by this standard. NOTE Phantom manufacturers are encouraged to ex
43、tend the frequency range to which phantoms are specified to enable tests of systems operating at fundamental and harmonic frequencies above 15 MHz. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition
44、 cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61391-1:2006, Ultrasonics Pulse-echo scanners Part 1:Techniques for calibrating spatial measurement systems and measurement of system point spread function response IEC 62127
45、-1:2007, Ultrasonics Hydrophones Part 1: Measurement and characterization of medical ultrasonic fields up to 40 MHz 3 Terms and definitions For the purposes of this document the following terms and definitions apply:3.1 A-scan class of data acquisition geometry in one dimension, in which echo streng
46、th information is acquired from points lying along a single beam axis and displayed as amplitude versus time of flight or distance IEC 61391-1:2006, definition 3.1 BS EN 61391-2:201061391-2 IEC:2010(E) 9 3.2 acoustic scan line (scan line) one of the component lines which form a B-mode image on an ul
47、trasound monitor, where each line is the envelope-detected A-scan line in which the echo amplitudes are converted to brightness values IEC 61391-1:2006, definition 3.26 3.3 acoustic working frequency arithmetic mean of the frequencies f1and f2at which the amplitude of the acoustic pressure spectrum
48、first falls 3dB below the main peak amplitude.IEC 61391-1:2006, definition 3.3, modified 3.4 attenuation coefficient at a specified frequency, the fractional decrease in plane wave amplitude per unit path length in the medium, specified for one-way propagation Units: m1(attenuation coefficient is ex
49、pressed in dB m1by multiplying the fractional decrease by 8,686 dB.) NOTE 1 When describing the attenuation properties of a material, the variation of attenuation with frequency should be given. This may be done by expressing a(f), the attenuation coefficient at frequency f, as a(f) = aofb,where f is in MHz, aois the attenuation coefficient at 1 MHz and b is a constant determined by least-squares fitting to experimental data poin
