SIST EN 61267:2006

SLOVENSKI SIST EN 61267:2006

STANDARD
junij 2006
Medicinska diagnostična rentgenska oprema - Sevalni pogoji pri ugotavljanju
karakteristik (IEC 61267:2005)
Medical diagnostic X-ray equipment - Radiation conditions for use in the
determination of characteristics (IEC 61267:2005)
ICS 11.040.50 Referenčna številka
SIST EN 61267:2006(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD
EN 61267

NORME EUROPÉENNE
January 2006
EUROPÄISCHE NORM

ICS 11.040.50 Supersedes EN 61267:1994


English version


Medical diagnostic X-ray equipment –
Radiation conditions for use in the determination of characteristics
(IEC 61267:2005)


Equipement de diagnostic médical  Medizinische diagnostische
à rayonnement X – Röntgeneinrichtung –
Conditions de rayonnement Bestrahlungsbedingungen zur
pour utilisation dans la détermination Bestimmung von Kenngrößen
des caractéristiques (IEC 61267:2005)
(CEI 61267:2005)




This European Standard was approved by CENELEC on 2005-12-01. 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, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and 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


© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61267:2006 E

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EN 61267:2006 - 2 -
Foreword
The text of document 62C/391/FDIS, future edition 2 of IEC 61267, prepared by SC 62C, Equipment for
radiotherapy, nuclear medicine and radiation dosimetry, of IEC TC 62, Electrical equipment in medical
practice, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61267
on 2005-12-01.
This European Standard supersedes EN 61267:1994.
The main changes compared to EN 61267:1994 include:
a) introduction of “practical peak voltage” for measuring X-ray tube voltage;
b) introduction of a new procedure for establishing the radiation qualities;
c) inserting of an informative Annex B “Determination of the amount of additional filtration” and a
normative Annex C “Measurement of the practical peak voltage”;
d) revision of radiation qualities and radiation conditions;
e) addition of term definitions.
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) 2006-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-12-01
This European Standard makes reference to International Standards. Where the International Standard
referred to has been endorsed as a European Standard or a home-grown European Standard exists, this
European Standard shall be applied instead. Pertinent information can be found on the CENELEC web
site.
In this standard, the following print types are used:
– requirements proper: roman type;
– test specifications: italic type;
– notes and explanatory matter: small roman type;
– TERMS USED THROUGHOUT THIS PARTICULAR STANDARD THAT ARE DEFINED IN CLAUSE 3, OR IN OTHER
STANDARDS: SMALL CAPITALS.
__________
Endorsement notice
The text of the International Standard IEC 61267:2005 was approved by CENELEC as a European
Standard without any modification.
__________

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NORME CEI
INTERNATIONALE
IEC



61267
INTERNATIONAL


Deuxième édition
STANDARD

Second edition

2005-11


Equipement de diagnostic médical
à rayonnement X –
Conditions de rayonnement pour utilisation dans
la détermination des caractéristiques

Medical diagnostic X-ray equipment –
Radiation conditions for use in the
determination of characteristics

 IEC 2005 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
X
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61267  IEC:2005 – 3 –
CONTENTS

FOREWORD.5
INTRODUCTION.9

1 Scope and object.13
2 Normative references .19
3 Terms and definitions .19
4 Common aspects − Adjustment procedures .23
5 RQR – RADIATION QUALITIES in RADIATION BEAMS emerging from the X-RAY SOURCE
ASSEMBLY.25
6 RQA – RADIATION QUALITIES based on a PHANTOM made up of an aluminium ADDED
FILTER.31
7 RQC – RADIATION QUALITIES based on copper ADDED FILTER .35
8 RQT – RADIATION QUALITIES based on copper ADDED FILTER .37
9 Standard RADIATION CONDITIONS RQN.41
10 Standard RADIATION CONDITIONS RQB.45
11 Standard RADIATION CONDITION RQR-M .47
12 Standard RADIATION CONDITION RQA-M.49
13 Standard RADIATION CONDITIONS RQN-M.51
14 Standard RADIATION CONDITION RQB-M.53

Annex A (informative) Rationale.69
Annex B (informative) Determination of the amount of additional filtration.71
ANNEX C (normative) Measurement of the PRACTICAL PEAK VOLTAGE .75
Annex D (informative) Overview of radiation qualities and radiation conditions .79

Bibliography.81

Index of defined terms .83

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61267  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________

MEDICAL DIAGNOSTIC X-RAY EQUIPMENT –
RADIATION CONDITIONS FOR USE IN THE
DETERMINATION OF CHARACTERISTICS


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 61267 has been prepared by subcommittee 62C: EQUIPMENT for
RADIOTHERAPY, nuclear medicine and RADIATION dosimetry, of IEC technical committee 62:
Electrical EQUIPMENT in medical practice.
This second edition cancels and replaces the first edition published in 1994. It constitutes a
technical revision. The main changes of the second edition of this standard include:
a) introduction of “practical peak voltage” for measuring X-ray tube voltage;
b) introduction of a new procedure for establishing the radiation qualities;
c) inserting of an informative Annex B “Determination of the amount of additional filtration”
and a normative Annex C “Measurement of the practical peak voltage”;
d) revision of radiation qualities and radiation conditions;
e) addition of term definitions.

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61267  IEC:2005 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
62C/391/FDIS 62C/393/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.
In this standard, the following print types are used:
– requirements proper: roman type;
– test specifications: italic type;
– notes and explanatory matter: small roman type;
– TERMS USED THROUGHOUT THIS PARTICULAR STANDARD THAT ARE DEFINED IN CLAUSE 3, OR IN
OTHER STANDARDS: SMALL CAPITALS.
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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61267  IEC:2005 – 9 –
INTRODUCTION
To establish characteristics, aspects or properties of ASSOCIATED EQUIPMENT or to have
available RADIATION BEAMS for physical and medical investigations, sets of well-defined
RADIATION CONDITIONS can offer an important tool in many situations.
From a regulation and standardization point of view there is a need:
− to have available well-defined RADIATION CONDITIONS that can be used internationally to
specify standards of operation of X-RAY EQUIPMENT;
− to provide a basis for the harmonization of existing national standards;
− to provide uniform sets of RADIATION CONDITIONS (a dictionary of RADIATION CONDITIONS) to
describe and judge the performance of X-RAY EQUIPMENT for the benefit of
MANUFACTURERS, USERS, PATIENTS and health protection authorities;
− to solve communication problems between MANUFACTURERS, USERS and regulatory
authorities, stemming from a lack of internationally accepted definitions and test methods.
From an application point of view, commonly accepted sets of RADIATION CONDITIONS would in
general find use in:
− QUALITY CONTROL tests by MANUFACTURERS;
− installation and ACCEPTANCE TESTS;
− calibration of test instrumentation;
− type approval tests (where required);
− inspection and tests by regulatory authorities and testing institutes;
− physical and medical studies in physical laboratories and medical facilities;
− determination of characteristics of ASSOCIATED EQUIPMENT.
Standard RADIATION CONDITIONS can benefit a number of potential users, such as:
MANUFACTURERS of X-RAY EQUIPMENT;
−
− MANUFACTURERS of X-ray test instrumentation;
− research laboratories;
− testing institutes;
− USERS;
− government regulatory authorities;
− service organizations;
− standardization organizations.
Some provisions and statements in the body of this International Standard require additional
information. Such information is presented in Annex A called "Rationale". An asterisk in the
left-hand margin of a clause or subclause indicates the presence of such additional
information.

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61267  IEC:2005 – 11 –
In this standard the X-RAY TUBE VOLTAGE is measured as the PRACTICAL PEAK VOLTAGE. The
rationale behind using this quantity is given in Annex C. A description of how the quantity
PRACTICAL PEAK VOLTAGE is measured is given in Annex C.
In the development of this edition of this standard efforts were made to set up procedures that
give a high degree of equivalence of standard RADIATION QUALITIES realized on different X-ray
machines. In the first edition the RADIATION QUALITIES were established by adjusting, within
given limits the X-RAY TUBE VOLTAGE to such a value that the required HALF-VALUE LAYER was
achieved. Depending on the total INHERENT FILTRATION an X-RAY TUBE VOLTAGE had to be
selected which could differ from the nominal value by as much as ±5 %. If the INHERENT
FILTRATION of the X-RAY TUBE was relatively strong this could be compensated by choosing a
lower X-RAY TUBE VOLTAGe and vice versa. For the example of a radiation quality with a
nominal X-RAY TUBE VOLTAGE of 100 kV this procedure meant that the tube voltage could be
set as low as 95 kV for a moderately filtered RADIATION QUALITY and as high as 105 kV for a
heavily filtered X-RAY TUBE. These two RADIATION QUALITIES were considered to be equivalent
as long as they both had the required HALF-VALUE LAYER.
This solution was not considered to be an ideal one. However, due to the lack of a suitable
and agreed definition of what is usually termed peak voltage no alternative was available.
With the arrival of the PRACTICAL PEAK VOLTAGE the situation has changed: With this quantity it
is possible by means of an electrical measurement to set the tube voltage of the x-ray
generator in question with any arbitrary shape of the ripple to a value that a radiograph taken
with a tube connected to this generator has the same low level contrast as a radiograph taken
with the same x-ray tube connected to a true constant potential generator operating at the
'correct' voltage.
Given the possibility of setting the tube voltage of any generator to the 'correct' value,
irrespective of the shape of the ripple, it becomes difficult to justify the deliberate selection of
a 'wrong' tube voltage to compensate for a below or an above average filtration of the x-ray
tube. The procedure, by which the radiation qualities are realized in this second edition,
consists of setting the X-RAY TUBE VOLTAGE to the 'correct' value and determining the amount
of filtration needed to produce the required HALF-VALUE LAYER. The nature of this process
implies that there is a certain maximum total INHERENT FILTRATION beyond which a given X-RAY
TUBE may no longer be used to produce a given RADIATION QUALITY. This is not new in
principle, but it is clearly expressed in this edition. In order not to exclude what are
considered as standard X-RAY TUBES, the HALF-VALUE LAYERS of some of the RADIATION
QUALITIES have been increased. The new HALF-VALUE LAYERS have been chosen in such a way
that it is possible to establish all RADIATION QUALITIES in this standard with an X-RAY TUBE with
2,5 mm Al hardening-equivalent filtration and with ANODE ANGLES down to 9°.
The procedure to be followed according to this edition for producing the RADIATION QUALITIES
of the RQR series does require a certain amount of additional effort. This additional effort is
largely compensated when the more heavily filtered radiation qualities are realized. The great
advantage of the new method lies in a much higher degree of equivalence of a given
RADIATION QUALITY with X-RAY TUBES having different INHERENT FILTRATIONS.

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61267  IEC:2005 – 13 –
MEDICAL DIAGNOSTIC X-RAY EQUIPMENT −
RADIATION CONDITIONS FOR USE IN THE
DETERMINATION OF CHARACTERISTICS


1 Scope and object
This International Standard applies to test procedures which, for the determination of
characteristics of systems or components of medical diagnostic X-RAY EQUIPMENT, require
well-defined RADIATION CONDITIONS.
Except for mammography, this standard does not apply to conditions where discontinuities in
radiation absorption of elements are deliberately used to modify properties of the RADIATION
BEAM (for example by rare earth filters).
RADIATION CONDITIONS as used for screen-film sensitometry are not covered in this standard.
NOTE Screen-film sensitometry is the subject of the ISO 9236 series.
This standard deals with methods for generating RADIATION BEAMS with RADIATION CONDITIONS
which can be used under test conditions typically found in test laboratories or in
manufacturing facilities for the determination of characteristics of medical diagnostic X-RAY
EQUIPMENT.
Examples of such RADIATION QUALITIES are RADIATION BEAMS emerging through the filtration
from the X-RAY SOURCE ASSEMBLY. RADIATION CONDITIONS represent the more general case,
where SCATTERED RADIATION emerges from an EXIT SURFACE of a PATIENT or a PHANTOM. This
requires a well defined geometrical arrangement.
The most complete specification of RADIATION FIELDS is given by the spectral distribution of the
photon fluence. Since the measurement of X-RAY SPECTRA is a demanding task, this standard
expresses RADIATION QUALITIES in terms of the X-RAY TUBE VOLTAGE, the first and second HALF-
VALUE LAYER. In the case of RADIATION CONDITIONS, specifications are performed additionally in
terms of PHANTOM properties and geometry.
The attempt to characterize a spectral distribution just by means of the X-RAY TUBE VOLTAGE,
the first and possibly the second HALF-VALUE LAYER is thus a compromise between the
mutually conflicting requirements of avoiding excessive efforts for establishing a RADIATION
QUALITY and of the complete absence of any ambiguity in the definition of a RADIATION
QUALITY. Due to differences in the design and the age of X-RAY TUBES in terms of anode angle,
anode roughening and INHERENT FILTRATION, two RADIATION QUALITIES produced at a given X-
RAY TUBE VOLTAGE having the same first HALF-VALUE LAYER can still have quite different
spectral distributions. Given the inherent ambiguity in the characterization of RADIATION
QUALITY, it is essential that further tolerances introduced by allowing certain ranges of values,
e.g. for X-RAY TUBE VOLTAGE and first HALF-VALUE LAYER, must be sufficiently small not to
jeopardise the underlying objective of this standard. This standard is to ensure that
measurements of the properties of medical diagnostic equipment should produce consistent
results if RADIATION QUALITIES or RADIATION CONDITIONS in compliance with this standard are
used.

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61267  IEC:2005 – 15 –
To achieve this objective, certain degrees of freedom in the way in which a RADIATION
CONDITION could be established in the framework of the first edition of this standard have been
removed. The essential restriction introduced in this second edition is that the X-RAY TUBE
VOLTAGE is measured and set to its 'correct' value. The second step is to attempt to establish
the prescribed first HALF-VALUE LAYER by adding into the beam the necessary amount of
ADDITIONAL FILTRATION. If the INHERENT FILTRATION provided by the X-RAY TUBE alone is so
strong that the HALF-VALUE LAYER of the RADIATION BEAM emerging from the X-RAY TUBE
ASSEMBLY as such is larger than that to be established, the X-RAY TUBE ASSEMBLY used is not
suited for producing the desired RADIATION CONDITION. This may occur if the anode angle of
the X-RAY TUBE ASSEMBLY is too small and/or in the case of excessive anode roughening due
to tube ageing.
In the approach outlined in the two preceding paragraphs the X-RAY TUBE VOLTAGE plays a
decisive role. It is therefore essential that the ‘correct’ X-ray tube voltage is chosen
irrespective of the type of high voltage generator connected to the X-RAY TUBE. The way in
which this is realized in this standard is by measuring the X-RAY TUBE VOLTAGE in terms of the
PRACTICAL PEAK VOLTAGE. This quantity is a weighted mean of all values of the X-RAY TUBE
VOLTAGE occurring during an exposure. The weighting is done in such a way that identical
values of the PRACTICAL PEAK VOLTAGE give identical values of the low level contrast on a
radiograph irrespective of the waveform supplied by the generator.
Although the PRACTICAL PEAK VOLTAGE can be measured non-invasively, the level of
uncertainty required in this standard demands the use of invasive techniques. The design and
age of the X-RAY TUBE ASSEMBLY influence the result of non-invasive measurements. When
PRACTICAL PEAK VOLTAGE is measured invasively, tube design and age have no influence on
the result of such a measurement.
In the framework of what is physically feasible, differences in tube design and ageing are
taken into account by adding the appropriate amount of ADDITIONAL FILTRATION.
In Annex C further explanations with regard to the PRACTICAL PEAK VOLTAGE are given.
This standard describes both primary RADIATION QUALITIES, which to a good approximation are
free of SCATTERED RADIATION (RQR, RQA, RQC, RQT, RQR-M and RQA-M) and, for PATIENT
simulation, RADIATION CONDITIONS containing SCATTERED RADIATION (RQN, RQB, RQN-M and
RQB-M).
It is crucial to be aware that in the presence of SCATTERED RADIATION the characteristics of X-
radiation in terms of fractions of AIR KERMA associated with the PRIMARY RADIATION and the
SCATTERED RADIATION depend on the position and nature of any ADDED FILTER or PHANTOM. It is
therefore obvious that AIR KERMA measurements in such RADIATION BEAMS need careful
consideration.
Clauses 5 to 9 deal with RADIATION CONDITIONS which are essentially free of SCATTERED
RADIATION. Due to the spatial homogeneity of these RADIATION CONDITIONS, the APPLICATION
DISTANCE does not influence the RADIATION CONDITIONS to a significant extent. These RADIATION
CONDITIONS are called RADIATION QUALITIES.
RADIATION QUALITIES of the RADIATION BEAM emerging from the X-RAY
• Clause 5 deals with
SOURCE ASSEMBLY. Such RADIATION QUALITIES can be used for determining ATTENUATION
properties of ASSOCIATED EQUIPMENT.
• Clause 6 deals with RADIATION QUALITIES of the RADIATION BEAM emerging from an irradiated
object, that simulates a PATIENT under the conditions that:

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61267  IEC:2005 – 17 –
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite
• Clauses 7 and 8 deal with RADIATION QUALITIES derived from those dealt with in Clause 6 in
view of special applications like automatic exposure and automatic brightness control
systems and computed tomographs. The radiation transmitted through the irradiated object
has properties similar to those of the radiation transmitted through a PATIENT under the
conditions that:
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite.
• Clauses 9 and 10 deal with RADIATION CONDITIONS where SCATTERED RADIATION is taken into
account. This is done either by limiting the amount of SCATTERED RADIATION by appropriate
means and/or providing specific additional information.
• Clause 9 deals with measuring arrangements primarily intended in combination with
RADIATION CONDITIONS RQB of Clause 10 to be used for those measurements where the
contribution of SCATTERED RADIATION to the detected signal is minimal and is known as
NARROW BEAM CONDITION.
• Clause 10 deals with RADIATION CONDITIONS to be used for measurements where the
contribution of SCATTERED RADIATION to the detected signal is significant and is known as
BROAD BEAM CONDITION.
For the RADIATION QUALITIES specified in Clauses 5 to 10 it is assumed that an X-RAY TUBE is
available with an anode angle of not less than about 9 degrees. For x-ray tubes with smaller
anode angles it may not be possible to realize some or all RADIATION QUALITIES of Clause 5. If
some or all RADIATION QUALITIES of the RQR series cannot be realized with a given X-RAY TUBE
due to a too strong INHERENT FILTRATION, some special provisions have been made to
establish nevertheless the more heavily filtered RADIATION QUALITIES in Clauses 6 to 10 which
are in principle based on the RADIATION QUALITIES of the RQR series.
In order to make allowance for the use of X-RAY TUBES with ANODE ANGLES down to 9°, the
HALF-VALUE LAYERS of RADIATION QUALITIES RQR 4 to RQR 10 have been increased with
respect to the values specified in the first edition of this standard (1994).
Clauses 11 to 14 deal with RADIATION CONDITIONS applicable to mammography.
• Clause 11 deals with RADIATION QUALITIES of the RADIATION BEAM emerging from the X-RAY
SOURCE ASSEMBLY. Such RADIATION QUALITIES can be used for determining ATTENUATION
properties of ASSOCIATED EQUIPMENT.
• Clause 12 deals with RADIATION QUALITIES transmitted through an irradiated object, that
simulates a PATIENT under the conditions that:
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite.
• CLAUSE 13 deals with RADIATION CONDITIONS to be used for studies in mammography
under NARROW BEAM CONDITION. These RADIATION CONDITIONS are achieved by applying a
special tissue-equivalent PHANTOM.

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