1、BRITISH STANDARDBS EN 61391-1:2006Ultrasonics Pulse-echo scanners Part 1: Techniques for calibrating spatial measurement systems and measurement of system point-spread function responseThe European Standard EN 61391-1:2006 has the status of a British StandardICS 17.140.50g49g50g3g38g50g51g60g44g49g4
2、2g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 61391-1:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 J
3、anuary 2007 BSI 2007ISBN 978-0-580-49923-4National forewordThis British Standard was published by BSI. It is the UK implementation of EN 61391-1:2006. It is identical with IEC 61391-1:2006.The UK participation in its preparation was entrusted to Technical Committee EPL/87, Ultrasonics.A list of orga
4、nizations represented on EPL/87 can be obtained on request 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 cannot confer immunity from legal obligations.Amen
5、dments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARD EN 61391-1 NORME EUROPENNE EUROPISCHE NORM October 2006 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secr
6、etariat: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61391-1:2006 E ICS 17.140.50 English version Ultrasonics - Pulse-echo scanners Part 1: Techniques for calibrating spatial measurem
7、ent systems and measurement of system point-spread function response (IEC 61391-1:2006) Ultrasons - Scanners impulsion et cho Partie 1: Techniques pour ltalonnage des systmes de mesure spatiaux et des mesures de la rponse de la fonction de dispersion ponctuelle du systme (CEI 61391-1:2006) Ultrascha
8、ll - Impuls-Echo-Scanner Teil 1: Verfahren fr die Kalibrierung von rumlichen Messsystemen und Messung der Charakteristik der Punktverwaschungsfunktion des Systems (IEC 61391-1:2006) This European Standard was approved by CENELEC on 2006-10-01. CENELEC members are bound to comply with the CEN/CENELEC
9、 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 CENE
10、LEC 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 versions.
11、 CENELEC members are the national electrotechnical committees of Austria, Belgium, 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, Slo
12、venia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of document 87/336/FDIS, future edition 1 of IEC 61391-1, prepared by IEC TC 87, Ultrasonics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61391-1 on 2006-10-01. The following dates were f
13、ixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2007-07-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2009-10-01 Terms in bold in the text are define
14、d in Clause 3. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61391-1:2006 was approved by CENELEC as a European Standard without any modification. _ 2 EN 61391-1:2006CONTENTS INTRODUCTION.4 1 Scope.5 2 Normative references5 3 Terms and definition
15、s .5 4 Symbols .11 5 General conditions11 6 Techniques for calibrating 2D-measurement systems13 6.1 Test methods 13 6.2 Instruments .13 6.3 Test settings14 6.4 Test parameters 15 7 Methods for calibrating 3D-measurement systems.17 7.1 General .17 7.2 Types of 3D-reconstruction methods18 7.3 Test par
16、ameters associated with reconstruction problems19 7.4 Test methods for measurement of 3D-reconstruction accuracy.20 8 Measurement of point-spread and line-spread functions (high-contrast spot size) 24 8.1 General .24 8.2 Test methods 25 8.3 Instruments .25 8.4 Test settings25 8.5 Test parameters 28
17、Annex A (normative) Test objects Calibration of 2D-spatial measurement systems.33 Annex B (normative) Test objects Measurement and calibration of 3D-image reconstruction accuracy 36 Annex C (normative) Test objects Measurement of point-spread function response39 Bibliography44 3 EN 61391-1:2006Annex
18、 ZA (normative) Normative references to international publications with their corresponding European publications.46 INTRODUCTION An ultrasonic pulse-echo scanner produces images of tissue in an ultrasonic scan plane by sweeping a narrow pulsed beam of ultrasound through the section of interest and
19、detecting the echoes generated at tissue boundaries. A variety of ultrasonic transducer types are employed to operate in a transmit/receive mode for the ultrasonic signals. Ultrasonic scanners are widely used in medical practice to produce images of many soft-tissue organs throughout the human body.
20、 This standard describes test procedures that should be widely acceptable and valid for a wide range of types of equipment. Manufacturers should use the standard to prepare their specifications; the users should employ the standard to check specifications. The measurements can be carried out without
21、 interfering with the normal working conditions of the machine. Typical test objects are described in the annexes. The structures of the test objects have not been specified in detail, rather suitable types of overall and internal structures are described. The specific structure of a test object sho
22、uld be reported with the results obtained using it. Similar commercial versions of these test objects are available. The performance parameters specified and the corresponding methods of measurement have been chosen to provide a basis for comparison with the manufacturers specification and between s
23、imilar types of apparatus of different makes, intended for the same kind of diagnostic application. The manufacturers specification should allow comparison with the results obtained from the tests in this standard. Furthermore, it is intended that the sets of results and values obtained from the use
24、 of the recommended methods will provide useful criteria for predicting the performance of equipment in appropriate diagnostic applications. This standard concentrates on measurements of images by digital techniques. Methods suitable for inspection by eye are covered here as well. Discussion of othe
25、r visual techniques can be found in IEC 61390 11). Where a diagnostic system accommodates more than one option in respect of a particular system component, for example the ultrasonic transducer, it is intended that each option be regarded as a separate system. However, it is considered that the perf
26、ormance of a machine is adequately 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. _ 1
27、)Figures in square brackets refer to the Bibliography. 4 EN 61391-1:2006ULTRASONICS PULSE-ECHO SCANNERS Part 1: Techniques for calibrating spatial measurement systems and measurement of system point-spread function response 1 Scope This International Standard describes methods of calibrating the spa
28、tial measurement facilities and point-spread function of ultrasonic imaging equipment in the ultrasonic frequency range 0,5 MHz to 15 MHz. This standard is relevant for ultrasonic scanners based on the pulse-echo principle of the types listed below: mechanical sector scanners; electronic phased-arra
29、y sector scanners; electronic linear-array scanners; electronic curved-array sector scanners; water-bath scanners based on any of the above four scanning mechanisms; 3D-volume reconstruction systems. 2 Normative references The following referenced documents are indispensable for the application of t
30、his document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61102:1991, Measurement and characterisation of ultrasonic fields using hydrophones in the frequency range 0,5 MHz to 15 M
31、Hz IEC 61685:2001, Ultrasonics Flow measurement systems Flow test object3 Terms and definitions For the purposes of this document, the following terms and definitions apply. See also related standards and technical reports for definitions and explanations. 1-5 3.1 A-scan class of data acquisition ge
32、ometry in one dimension, in which echo strength information is acquired from points lying along a single beam axis and displayed as amplitude versus time of flight or distance 5 EN 61391-1:20063.2 acoustic coupling agent (also, coupling agent) a material, usually a gel or other fluid, that is used t
33、o ensure acoustic contact between the transducer and the patients skin, or between the transducer and the surface of a sealed test object 3.3 acoustic working frequency arithmetic mean of the frequencies f1and f2at which the amplitude of the acoustic pressure spectrum is 3 dB below the peak amplitud
34、e (See 3.4.2 of IEC 61102) 3.4 automatic time-gain compensation ATGC automatic working time gain control based on the observed decrease in echo amplitudes due to the attenuation in ultrasonic pulse amplitude with depth 3.5 axial resolution minimum separation along the beam axis of two equally scatte
35、ring volumes or targets at a specified depth for which two distinct echo signals can be displayed 3.6 backscatter coefficient mean acoustic power scattered in the 180 direction by a specified object with respect to the direction of the incident beam, per unit solid angle per unit volume, divided by
36、the incident beam intensity. For a volume filled with many scatterers, the scatterers are considered to be randomly distributed. The mean power is obtained from different spatial realisations of the scattering volume NOTE Backscatter coefficient is commonly referred to as the differential scattering
37、 cross-section per unit volume in the 180 direction 3.7 backscatter contrast (normalized) difference between the backscatter coefficients from two defined regions divided by the square root of the product of the two backscatter coefficients 3.8 beam axis the longitudinal axis of the pulse-echo respo
38、nse pattern of a given B-mode scan line, a pulse-echo equivalent to the transmitted beam axis of IEC 61828 2 3.9 B-scan class of data acquisition geometry in which echo information is acquired from points lying in an ultrasonic scan plane containing interrogating ultrasonic beams. See B-mode below.
39、NOTE B-scan is a colloquial term for B-mode scan or image. (See 3.10) 6 EN 61391-1:20063.10 Brightness-modulated display B-mode method of presentation of B-scan information in which a particular section through an imaged object is represented in a conformal way by the scan plane of the display and e
40、cho amplitude is represented by local brightness or optical density of the display IEC 60854: definition 3.18, modified 3.11 displayed dynamic range ratio, expressed in decibels, of the amplitude of the maximum echo that does not saturate the display to the minimum echo that can be distinguished in
41、the display under the scanner test settings 3.12 elevational resolution minimum separation perpendicular to the ultrasonic scan plane of two equally scattering targets at a specified depth for which two distinct echo signals can be displayed. Often used here informally for slice thickness for purpos
42、es of 3D-scanning 3.13 field-of-view area in the ultrasonic scan plane which is insonated by the ultrasound beam during the acquisition of echo data to produce one image frame 3.14 frame rate number of sweeps comprising the full-frame refresh rate that the ultrasonic beam makes per second through th
43、e field-of-view 3.15 gain ratio of the output to the input of a system, generally an amplifying system, usually expressed in decibels 3.16 grey scale range of values of image brightness, being either continuous between two extreme values or, if discontinuous, including at least three discrete values
44、 IEC 60854: definition 3.14 3.17 lateral resolution minimum separation of two line targets at a specified depth in a test object made of tissue-mimicking material for which two distinct echo signals can be displayed. The line targets should be perpendicular to the scanned plane; the separation betwe
45、en the targets should be perpendicular to the beam-alignment axis 3.18 line-spread function LSF characteristic response in three dimensions of an imaging system to a high-contrast line target 7 EN 61391-1:20063.19 line target cylindrical reflector whose diameter is so small that the reflector cannot
46、 be distinguished by the imaging system from a cylindrical reflector with diameter an order of magnitude smaller, except by signal amplitude. The backscatter from a standard line target should be a simple function of frequency over the range of frequencies studied 3.20 M-mode time-motion mode method
47、 of presentation of M-scan information in which the motion of structures along a fixed beam axis is depicted by presenting their positions on a line which moves across a display to show the variation with time of the echo 3.21 M-scan time-motion scan class of acquisition geometry in which echo infor
48、mation from moving structures is acquired from points lying along a single beam axis. The echo strength information is presented using an M-mode display 3.22 nominal frequency (of a transducer) intended acoustic working frequency of a transducer as quoted by the designer or manufacturer adapted from
49、 definition 3.7 of IEC 60854 3.23 pixel picture element smallest spatial unit or cell size of a digitized 2-dimensional array representation of an image. Each pixel has an address (x-and y-coordinates corresponding to its position in the array) and a specific brightness level NOTE Pixel is a contraction of picture element. 3.24 point target reflector whose scattering surface dimensions are so small that it cannot be distinguished (except by signal amplitude) by the imaging
