SIST EN 62220-1-3:2008

Medical electrical equipment - Characteristics of digital X-ray imaging devices -- Part 1-3: Determination of the detective quantum efficiency - Detectors used in dynamic imaging

This part of IEC 62220 specifies the method for the determination of the DETECTIVE QUANTUM EFFICIENCY (DQE) of DIGITAL 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 1-3 is restricted to DIGITAL X-RAY IMAGING DEVICES that are used for dynamic imaging such as, but not exclusively, direct and indirect flat panel-detector based systems. It is not recommended to use this part of IEC 62220 for digital X-RAY IMAGE INTENSIFIER-based systems. This part of IEC 62220 is not applicable to: - DIGITAL X-RAY IMAGING DEVICES intended to be used in mammography or in dental radiography; - COMPUTED TOMOGRAPHY; and - systems in which the X-ray field is scanned across the patient.

Medizinische elektrische Geräte - Merkmale digitaler Röntgenbildgeräte - Teil 1-3: Bestimmung der detektiven Quanten-Ausbeute - Bildempfänger für dynamische Bildgebung

Appareils électromédicaux - Caractéristiques des dispositifs d'imagerie numérique à rayonnement X -- Partie 1-3: Détermination de l'efficacité quantique de détection - Détecteurs utilisés en imagerie dynamique

La CEI 62220-1-3:2008 spécifie la méthode de la détermination de l'efficacité quantique de détection (EQD) des dispositifs d'imagerie numérique à rayonnement X en fonction du kerma dans l'air et de la fréquence spatiale pour les conditions de fonctionnement dans la gamme des applications médicales, suivant les spécifications du fabricant. Les utilisateurs prévus de la présente partie de la CEI 62220 sont les fabricants et les laboratoires d'essai bien équipés.La présente partie 1-3 se limite aux dispositifs d'imagerie numérique à rayonnement X qui sont utilisés pour l'imagerie dynamique telle que, mais pas exclusivement, des systèmes à base de détecteurs plans direct ou indirect. Il n'est pas recommandé d'utiliser cette partie de la CEI 62220 pour des systèmes basés sur un intensificateur d'image radiologique.

Medicinska električna oprema - Karakteristike digitalnih naprav za rentgensko slikanje - 1-3. del: Ugotavljanje kvantne učinkovitosti odkrivanja - Detektorji pri dinamičnem slikanju (IEC 62220-1-3:2008)

General Information

• Status: Published
• Publication Date: 22-Sep-2008
• ICS: 11.040.50 - Radiographic equipment
• Technical Committee: IEMO - Electrical equipment in medical practice
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 15-Sep-2008
• Due Date: 20-Nov-2008
• Completion Date: 23-Sep-2008
• Directive: 93/42/EEC - Council Directive 93/42/EEC of 14 June 1993 concerning medical devices
• Ref Project: EN 62220-1-3:2008 - Medical electrical equipment - Characteristics of digital X-ray imaging devices - Part 1-3: Determination of the detective quantum efficiency - Detectors used in dynamic imaging

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 62220-1-3:2008
01-november-2008
0HGLFLQVNDHOHNWULþQDRSUHPD.DUDNWHULVWLNHGLJLWDOQLKQDSUDY]DUHQWJHQVNR
VOLNDQMHGHO8JRWDYOMDQMHNYDQWQHXþLQNRYLWRVWLRGNULYDQMD'HWHNWRUMLSUL
GLQDPLþQHPVOLNDQMX,(&
Medical electrical equipment - Characteristics of digital X-ray imaging devices - Part 1-3:
Determination of the detective quantum efficiency - Detectors used in dynamic imaging
(IEC 62220-1-3:2008)
Medizinische elektrische Geräte - Merkmale digitaler Röntgenbildgeräte - Teil 1-3:
Bestimmung der detektiven Quanten-Ausbeute - Bildempfänger für dynamische
Bildgebung (IEC 62220-1-3:2008)
Appareils électromédicaux - Caractéristiques des dispositifs d'imagerie numérique à
rayons X - Partie 1-3: Détermination de l'efficacité quantique de détection - Détecteurs
utilisés en imagerie dynamique (CEI 62220-1-3:2008)
Ta slovenski standard je istoveten z: EN 62220-1-3:2008
ICS:
11.040.50 Radiografska oprema Radiographic equipment
SIST EN 62220-1-3:2008 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 62220-1-3:2008

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SIST EN 62220-1-3:2008

EUROPEAN STANDARD
EN 62220-1-3

NORME EUROPÉENNE
September 2008
EUROPÄISCHE NORM

ICS 11.040.50


English version


Medical electrical equipment -
Characteristics of digital X-ray imaging devices -
Part 1-3: Determination of the detective quantum efficiency -
Detectors used in dynamic imaging
(IEC 62220-1-3:2008)


Appareils électromédicaux -  Medizinische elektrische Geräte -
Caractéristiques des dispositifs d'imagerie Merkmale digitaler Röntgenbildgeräte -
numérique à rayonnement X - Teil 1-3: Bestimmung der
Partie 1-3: Détermination de detektiven Quanten-Ausbeute -
l'efficacité quantique de détection - Bildempfänger für
Détecteurs utilisés en imagerie dynamique dynamische Bildgebung
(CEI 62220-1-3:2008) (IEC 62220-1-3:2008)




This European Standard was approved by CENELEC on 2008-07-01. 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 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, 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.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, 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.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62220-1-3:2008 E

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SIST EN 62220-1-3:2008
EN 62220-1-3:2008 - 2 -
Foreword
The text of document 62B/694/FDIS, future edition 1 of IEC 62220-1-3, 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 62220-1-3 on 2008-07-01.
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) 2009-04-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-07-01
In this standard, terms printed in SMALL CAPITALS are used as defined in IEC/TR 60788, in Clause 3 of this
standard or in 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 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 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 avoiding 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 stated 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.
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directive MDD (93/42/EEC). See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________

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SIST EN 62220-1-3:2008
- 3 - EN 62220-1-3:2008
Endorsement notice
The text of the International Standard IEC 62220-1-3:2008 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 62220-1 NOTE  Harmonized as EN 62220-1:2004 (not modified).
IEC 62220-1-2 NOTE  Harmonized as EN 62220-1-2:2007 (not modified).
IEC 61262-5 NOTE  Harmonized as EN 61262-5:1994 (not modified).
__________

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SIST EN 62220-1-3:2008
EN 62220-1-3:2008 - 4 -
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 references, 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

1) 2)
IEC 60336 - Medical electrical equipment - X-ray tube EN 60336 2005
assemblies for medical diagnosis -
Characteristics of focal spots


IEC/TR 60788 2004 Medical electrical equipment - - -
Glossary of defined terms


3)
IEC 61267 1994 Medical diagnostic X-ray equipment - EN 61267 1994
Radiation conditions for use in the
determination of characteristics


ISO 12232 1998 Photography - Electronic still-picture - -
cameras - Determination of ISO speed



1)
Undated reference.
2)
Valid edition at date of issue.
3)
IEC 61267:2005 is harmonised as EN 61267:2006 (not modified).

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SIST EN 62220-1-3:2008
- 5 - EN 62220-1-3:2008
Annex ZZ
(informative)

Coverage of Essential Requirements of EC Directives

This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers all
relevant essential requirements as given in Annex I of the EC Directive 93/42/EEC

Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive concerned.

WARNING: Other requirements and other EC Directives may be applicable to the products falling within
the scope of this standard.

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SIST EN 62220-1-3:2008

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SIST EN 62220-1-3:2008
IEC 62220-1-3
Edition 1.0 2008-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Medical electrical equipment – Characteristics of digital X-ray imaging devices –
Part 1-3: Determination of the detective quantum efficiency – Detectors used in
dynamic imaging

Appareils électromédicaux – Caractéristiques des dispositifs d’imagerie
numérique à rayonnement X –
Partie 1-3: Détermination de l'efficacité quantique de détection – Détecteurs
utilisés en imagerie dynamique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
V
CODE PRIX
ICS 11.040.50 ISBN 2-8318-9826-9

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SIST EN 62220-1-3:2008
– 2 – 62220-1-3 © IEC:2008
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms and definitions .8
4 Requirements .10
4.1 Operating conditions .10
4.2 X-RAY EQUIPMENT .10
4.3 RADIATION QUALITY .10
4.4 TEST DEVICE.11
4.5 Geometry .12
4.6 IRRADIATION conditions .14
4.6.1 General conditions .14
4.6.2 AIR KERMA measurement .15
4.6.3 LAG EFFECTS.16
4.6.4 IRRADIATION to obtain the CONVERSION FUNCTION .16
4.6.5 IRRADIATION for determination of the NOISE POWER SPECTRUM and LAG
EFFECTS .16
4.6.6 IRRADIATION with TEST DEVICE in the RADIATION BEAM.17
4.6.7 Overview of all necessary IRRADIATIONS .18
5 Corrections of RAW DATA .18
6 Determination of the DETECTIVE QUANTUM EFFICIENCY .19
6.1 Definition and formula of DQE(u,v).19
6.2 Parameters to be used for evaluation .19
6.3 Determination of different parameters from the images.20
6.3.1 Linearization of data .20
6.3.2 The LAG EFFECTS corrected NOISE POWER SPECTRUM (NPS) .20
6.3.3 Determination of the MODULATION TRANSFER FUNCTION (MTF).24
7 Format of conformance statement .24
8 Accuracy .25
Annex A (informative) Determination of LAG EFFECTS.26
Annex B (informative) Calculation of the input NOISE POWER SPECTRUM .29
Bibliography.30
Index of defined terms .32

Figure 1 – TEST DEVICE .12
Figure 2 – Geometry for exposing the DIGITAL X-RAY IMAGING DEVICE in order to
determine the CONVERSION FUNCTION, the NOISE POWER SPECTRUM and the MODULATION
TRANSFER FUNCTION behind the TEST DEVICE.14
Figure 3 – Image acquisition sequence to determine the NOISE POWER SPECTRUM and
LAG EFFECTS.17
Figure 4 – Geometric arrangement of the ROIs .21
Figure A.1 – Power spectral density of white noise s and correlated signal g (only
positive frequencies are shown).27

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SIST EN 62220-1-3:2008
62220-1-3 © IEC:2008 – 3 –
Table 1 – RADIATION QUALITY (IEC 61267:1994) for the determination of DETECTIVE
QUANTUM EFFICIENCY and corresponding parameters .11
Table 2 – Necessary IRRADIATIONS .18
Table 3 – Parameters mandatory for the application of this standard .20

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SIST EN 62220-1-3:2008
– 4 – 62220-1-3 © IEC:2008
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MEDICAL ELECTRICAL EQUIPMENT –
CHARACTERISTICS OF DIGITAL X-RAY IMAGING DEVICES –

Part 1-3: Determination of the detective quantum efficiency –
Detectors used in dynamic imaging


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 co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62220-1-3 has been prepared by subcommittee 62B: Diagnostic
imaging equipment, of IEC technical committee 62: Electrical equipment in medical practice.
The text of this standard is based on the following documents:
FDIS Report on voting
62B/694/FDIS 62B/702/RVD

Full 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 the ISO/IEC Directives, Part 2.

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SIST EN 62220-1-3:2008
62220-1-3 © IEC:2008 – 5 –
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 as defined in IEC 60788, in Clause
3 of this standard or in 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 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 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 avoiding 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 stated 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 contents 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.

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SIST EN 62220-1-3:2008
– 6 – 62220-1-3 © IEC:2008
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 define
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 imaging 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, DQE values can
also be considered to describe the dose efficiency of a given DIGITAL X-RAY IMAGING DEVICE.
NOTE 1 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 observer is not yet
1)
completely understood [1], [3].
NOTE 2 IEC 61262-5 specifies a method to determine the DQE of X-RAY IMAGE INTENSIFIERS at nearly zero
SPATIAL FREQUENCY. It focuses only on the electro-optical components of X-RAY IMAGE INTENSIFIERS, not on the
imaging properties as this standard does. As a consequence, the output is measured as an optical quantity
(luminance), and not as digital data. Moreover, IEC 61262-5 prescribes the use of a RADIATION SOURCE ASSEMBLY,
whereas this standard prescribes the use of an X-RAY TUBE. The scope of IEC 61262-5 is limited to X-RAY IMAGE
INTENSIFIERS and does not interfere with the scope of this standard.
The DQE is already widely used by manufacturers to describe the performance of their
DIGITAL X-RAY IMAGING DEVICE. The specification of the DQE is also required by regulatory
agencies (such as the Food and Drug Administration (FDA)) for admission procedures.
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 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 be beneficial for manufacturers, users, distributors and regulatory agencies.
It is the third document out of a series of three related standards:
• Part 1, which is intended to be used in RADIOGRAPHY, excluding MAMMOGRAPHY and
RADIOSCOPY.
• Part 1-2, which is intended to be used for MAMMOGRAPHY.
• the present 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 IEC 62220 standards
describing the relevant parameters of DIGITAL X-RAY IMAGING DEVICES.
———————
1)
Figures in square brackets refer to the bibliography.

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SIST EN 62220-1-3:2008
62220-1-3 © IEC:2008 – 7 –
MEDICAL ELECTRICAL EQUIPMENT –
CHARACTERISTICS OF DIGITAL X-RAY IMAGING DEVICES –

Part 1-3: Determination of the detective quantum efficiency –
Detectors used in dynamic imaging



1 Scope
This part of IEC 62220 specifies the method for the determination of the DETECTIVE QUANTUM
EFFICIENCY (DQE) of DIGITAL 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 1-3 is restricted to DIGITAL X-RAY IMAGING DEVICES that are used for dynamic imaging
such as, but not exclusively, direct and indirect flat panel-detector based systems.
It is not recommended to use this part of IEC 62220 for digital X-RAY IMAGE INTENSIFIER-based
systems.
NOTE 1 This negative recommendation is based on the low frequency drop, vignetting and geometrical distortion
present in these devices which may put severe limitations on the applicability of the measurement methods
described in this standard.
This part of IEC 62220 is not applicable to:
– DIGITAL X-RAY IMAGING DEVICES intended to be used in mammography or in dental
radiography;
– COMPUTED TOMOGRAPHY; and
– systems in which the X-ray field is scanned across the patient.
NOTE 2 The devices noted above are excluded because they contain many parameters (for instance, beam
qualities, geometry, time dependence, etc.) which differ from those important for dynamic imaging. Some of these
techniques are treated in separate standards (IEC 62220-1 and IEC 62220-1-2).
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 referenced document (including any amendments) applies.
IEC 60336, Medical electrical equipment – X-ray tube assemblies for medical diagnosis –
Characteristics of focal spots
IEC TR 60788:2004, Medical electrical equipment – Glossary of defined terms
2)
IEC 61267:1994, Medical diagnostic X-ray equipment – Radiation conditions for use in the
determination of characteristics
ISO 12232:1998, Photography – Electronic still-picture cameras – Determination of ISO speed
———————
2)
Although a second edition (2005) of IEC 61267 exists, reference to the first edition (IEC 61267:1994) is
expressly retained throughout this standard for reasons of harmonization within the IEC62220 family. (See 4.3,
Note 1.)

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SIST EN 62220-1-3:2008
– 8 – 62220-1-3 © IEC:2008
3 Terms and definitions
For the purpose of this document, the terms and definitions given in IEC 60788 and the
following apply.
3.1
CENTRAL AXIS
ENTRANCE PLANE passing through the centre of the entrance field
line perpendicular to the
[IEC 62220-1:2003, definition 3.1]
3.2
CONVERSION FUNCTION
plot of the large area output level (ORIGINAL DATA) of a DIGITAL X-RAY IMAGING DEVICE versus
the number of exposure quanta per unit area (Q) in the DETECTOR SURFACE plane
[IEC 62220-1:2003, definition 3.2]
NOTE 1 Q is to be calculated by multiplying the measured AIR KERMA excluding back scatter by the value given in
column 2 of Table 3.
NOTE 2 Many calibration laboratories, such as national metrology institutes, calibrate RADIATION METERS to
measure AIR KERMA.
3.3
DETECTIVE QUANTUM EFFICIENCY
DQE(u,v)
ratio of two NOISE POWER SPECTRUM (NPS) functions with the numerator being the NPS of the
input signal at the DETECTOR SURFACE of a digital X-ray detector after having gone through the
deterministic filter given by the system transfer function, and the denominator being the
measured NPS of the output signal (ORIGINAL DATA)
NOTE Instead of the two-dimensional DETECTIVE QUANTUM EFFICIENCY, often a cut through the two-dimensional
DETECTIVE QUANTUM EFFICIENCY along a specified SPATIAL FREQUENCY axis is published.
[IEC 62220-1:2003, definition 3.3]
3.4
DETECTOR SURFACE
accessible area which is closest to the IMAGE RECEPTOR PLANE
NOTE After removal of all parts (including the ANTI-SCATTER GRID and components for AUTOMATIC EXPOSURE
CONTROL, if applicable) that can be safely removed from the RADIATION BEAM without damaging the digital X-ray
detector.
[IEC 62220-1:2003, definition 3.4]
3.5
DIGITAL X-RAY IMAGING DEVICE
device consisting of a digital X-ray detector including the protective layers installed for use in
practice, the amplifying and digitizing electronics, and a computer providing the ORIGINAL DATA
(DN) of the image
[IEC 62220-1:2003, definition 3.5]
3.6
IMAGE MATRIX
arrangement of matrix elements preferentially in a Cartesian coordinate system
[IEC 62220-1:2003, definition 3.6]

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SIST EN 62220-1-3:2008
62220-1-3 © IEC:2008 – 9 –
3.7
LAG EFFECT
influence from a previous image on the current one
[IEC 62220-1:2003, definition
...