IEC 61223-3-7:2021

IEC 61223-3-7 ®
Edition 1.0 2021-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Evaluation and routine testing in medical imaging departments –
Part 3-7: Acceptance and constancy tests – Imaging performance of X-ray
equipment for dental cone beam computed tomography

Essais d'évaluation et de routine dans les services d'imagerie médicale –
Partie 3-7: Essais d'acceptation et de constance – Performance d'imagerie des
appareils à rayonnement X pour la tomodensitométrie dentaire à faisceau
conique
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 18 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Découvrez notre puissant moteur de recherche et consultez
webstore.iec.ch/advsearchform gratuitement tous les aperçus des publications. Avec un
La recherche avancée permet de trouver des publications IEC abonnement, vous aurez toujours accès à un contenu à jour
en utilisant différents critères (numéro de référence, texte, adapté à vos besoins.
comité d’études, …). Elle donne aussi des informations sur les
projets et les publications remplacées ou retirées. Electropedia - www.electropedia.org

Le premier dictionnaire d'électrotechnologie en ligne au monde,
IEC Just Published - webstore.iec.ch/justpublished
avec plus de 22 000 articles terminologiques en anglais et en
Restez informé sur les nouvelles publications IEC. Just
français, ainsi que les termes équivalents dans 16 langues
Published détaille les nouvelles publications parues.
additionnelles. Egalement appelé Vocabulaire
Disponible en ligne et une fois par mois par email.
Electrotechnique International (IEV) en ligne.

Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC online collection - oc.iec.ch

IEC 61223-3-7 ®
Edition 1.0 2021-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Evaluation and routine testing in medical imaging departments –

Part 3-7: Acceptance and constancy tests – Imaging performance of X-ray

equipment for dental cone beam computed tomography

Essais d'évaluation et de routine dans les services d'imagerie médicale –

Partie 3-7: Essais d'acceptation et de constance – Performance d'imagerie des

appareils à rayonnement X pour la tomodensitométrie dentaire à faisceau

conique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 11.040.50 ISBN 978-2-8322-1032-4

– 2 – IEC 61223-3-7:2021 © IEC 2021
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope and object . 8
2 Normative references . 9
3 Terms and definitions . 9
4 General aspects of ACCEPTANCE TESTS and CONSTANCY TESTS . 11
4.1 Preconditions . 11
4.2 General conditions to be considered in testing . 11
4.2.1 PHANTOM . 11
4.2.2 AIR KERMA . 12
4.3 Documents and data for the tests in the ACCOMPANYING DOCUMENTS . 12
4.4 Measuring INSTRUMENTS . 12
4.5 MAJOR SERVICE ACTION . 12
4.6 Record and establishment of BASELINE VALUES and TEST frequencies . 12
5 Performance tests for DENTAL CBCT EQUIPMENT . 13
5.1 Visual inspection . 13
5.2 Functional test . 13
5.3 Relationship between X-RAY FIELD and EFFECTIVE IMAGE RECEPTION AREA . 13
5.3.1 Requirement . 13
5.3.2 Test . 13
5.4 Reproducibility of the AIR KERMA . 13
5.4.1 Requirement . 13
5.4.2 Test . 14
5.5 Geometric accuracy . 14
5.5.1 General . 14
5.5.2 Requirement . 14
5.5.3 Test . 14
5.6 * Spatial resolution . 14
5.6.1 General . 14
5.6.2 Requirement . 14
5.6.3 Test . 15
5.7 * CONTRAST TO NOISE RATIO . 15
5.7.1 General . 15
5.7.2 Requirement . 15
5.7.3 Test . 15
5.8 * Acceptance index . 15
5.8.1 General . 15
5.8.2 Requirement . 15
5.8.3 Test . 15
5.9 * Homogeneity . 16
5.9.1 General . 16
5.9.2 Requirement . 16
5.9.3 Test . 16
5.10 ARTEFACTS . 17
5.10.1 General . 17
5.10.2 Requirement . 17

5.10.3 Test . 17
Annex A (informative) Rationales . 18
A.1 General conditions to be considered in PHANTOM based test procedures. 18
A.2 HOMOGENEITY . 18
A.3 Simplified determination of the MODULATION TRANSFER FUNCTION . 18
A.4 Spatial resolution . 18
A.5 CONTRAST TO NOISE RATIO . 19
A.6 AIR KERMA . 19
A.7 ACCEPTANCE INDEX . 21
Annex B (informative) Particular guidance and rationale . 23
B.1 Execution of the performance tests . 23
B.2 MODULATION TRANSFER FUNCTION . 23
B.2.1 General . 23
B.2.2 Scan geometries for the air kerma index . 24
B.2.3 HOMOGENEITY. 25
Annex C (normative) PHANTOM – Design . 26
Annex D (normative) Determination of the MODULATION TRANSFER FUNCTION . 29
D.1 MTF method 1: Simplified determination of the MODULATION TRANSFER
FUNCTION . 29
D.1.1 General . 29
D.1.2 Calculation procedure . 29
D.2 MTF method 2: Determination of the MODULATION TRANSFER FUNCTION . 30
Annex E (normative) Calculation of the CONTRAST TO NOISE ratio . 32
E.1 Overview. 32
E.1.1 General . 32
E.1.2 Procedure 1 . 32
E.1.3 Procedure 2 . 32
E.2 Calculation procedure . 33
E.2.1 General . 33
E.2.2 Procedure 1 . 33
E.2.3 Procedure 2 . 34
Annex F (informative) Examples of ARTEFACTS seen in ACCEPTANCE and CONSTANCY
TESTS . 35
F.1 General . 35
F.2 Ring ARTEFACTS . 35
F.3 Geometry ARTEFACTS . 36
F.3.1 General . 36
F.3.2 Blurred edges visible at the interface between PVC and air region . 36
F.3.3 Shading close to the edge of the PHANTOM . 37
Annex G (informative) AIR KERMA in DENTAL CBCT EQUIPMENT . 38
G.1 Background. 38
G.2 Conditions for the measurement of AIR KERMA in DENTAL CBCT EQUIPMENT . 38
G.2.1 Imaged volume . 38
G.2.2 Scanning geometry . 38
G.2.3 Measurement devices . 38
G.3 Summary . 39
Bibliography . 40
Index of defined terms . 41

– 4 – IEC 61223-3-7:2021 © IEC 2021

Figure A.1 – Geometry (example 1) . 20
Figure A.2 – Geometry (example 2) . 21
Figure B.1 – Example of the position and borders of the ROI for determination of the
MODULATION TRANSFER FUNCTION . 23
Figure B.2 – Example for the representation of the MODULATION TRANSFER FUNCTION . 24
Figure B.3 – Horizontal slice through a scan geometry (example 1) . 24
Figure B.4 – Horizontal slice through a scan geometry (example 2) . 25
Figure B.5 – Example for the position and borders of the fields for the determination of
HOMOGENEITY . 25
Figure C.1 – Structure and example of placement of the PHANTOM including the optional
parts (2a and 2d) within the path of the RADIATION BEAM . 26
Figure C.2 – Homogeneous parts of the PHANTOM . 27
Figure C.3 – Structure elements of the PHANTOM, axial and sagittal sections . 28
Figure E.1 – Placement of a REGION OF INTEREST (ROI) . 32
Figure E.2 – Example of the placement of REGION OF INTEREST (ROI) . 33
Figure F.1 – Axial slice illustrating a ring ARTEFACT at PMMA region of the PHANTOM . 35
Figure F.2 – Axial slice illustrating a ring ARTEFACT at PMMA/PVC region of the
PHANTOM . 36
Figure F.3 – Reference image without geometry ARTEFACTS . 36
Figure F.4 – Blurred edges visible at the interface between PVC and air region . 37
Figure F.5 – Shading close to the edge of the PHANTOM . 37

Table 1 – Additional requirements in ACCOMPANYING DOCUMENTS . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EVALUATION AND ROUTINE TESTING
IN MEDICAL IMAGING DEPARTMENTS –

Part 3-7: Acceptance and constancy tests – Imaging performance
of X-ray equipment for dental cone beam computed tomography

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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 61223-3-7 has been prepared by subcommittee 62B: Diagnostic
imaging equipment, of IEC technical committee 62: Electrical equipment in medical practice.
The text of this International Standard is based on the following documents:
FDIS Report on voting
62B/1249/FDIS 62B/1255/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 6 – IEC 61223-3-7:2021 © IEC 2021
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
In this document, the following print types are used:
– requirements and definitions: roman type.
– test specifications: italic type.
– informative material appearing outside of tables, such as notes, examples and references: smaller type;
normative text of tables is also in a smaller type.
– TERMS DEFINED IN CLAUSE 3 OF THIS DOCUMENT OR AS NOTED: SMALL CAPITALS.
References to clauses within this document are preceded by the term "Clause" followed by the
clause number. References to subclauses within this document are by number only.
In this document, the conjunctive "or" is used as an "inclusive or" so a statement is true if any
combination of the conditions is true.
The verbal forms used in this document conform to usage described in Clause 7 of the
ISO/IEC Directives, Part 2. For the purposes of this document, the auxiliary verb:
– "shall" means that compliance with a requirement or a test is mandatory for compliance with
this document;
– "should" means that compliance with a requirement or a test is recommended but is not
mandatory for compliance with this document;
– "may" is used to describe a permissible way to achieve compliance with a requirement or
test.
An asterisk (*) as the first character of a title or at the beginning of a paragraph or table title
indicates that there is guidance or rationale related to that item in Annex A.
A list of all parts of the IEC 61223 series, published under the general title Evaluation and
routine testing in medical imaging departments, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

INTRODUCTION
This document provides methods for acceptance testing and constancy testing for DENTAL CONE-
BEAM COMPUTED TOMOGRAPHY X-RAY EQUIPMENT.
The complete set of ACCEPTANCE TESTS is to be carried out after the EQUIPMENT has been
installed, or a subset of the tests is to be carried out after each MAJOR SERVICE ACTION that is
made to installed EQUIPMENT. This is done to facilitate verification of applicable safety and
performance standards, regulations, and published and/or contractual specifications that
influence the image quality, RADIATION OUTPUT and PATIENT positioning.
The complete set of CONSTANCY TESTS is to be carried out periodically at installed EQUIPMENT.
This is done to facilitate verification of stability of the EQUIPMENT according to the applicable
safety and performance standards, regulations, and published and/or contractual specifications
that influence the image quality, RADIATION OUTPUT and PATIENT positioning.
To maintain the homogeneity of this IEC standard with the other IEC standards addressing
DENTAL EXTRA-ORAL X-RAY EQUIPMENT, the measuring methods and the terminology are taken as
applicable from the safety standard IEC 60601-2-63:2012+AMD1:2017+AMD2:2021.
Some provisions or statements in this document require additional information, which is
presented in the annexes.
– 8 – IEC 61223-3-7:2021 © IEC 2021
EVALUATION AND ROUTINE TESTING
IN MEDICAL IMAGING DEPARTMENTS –

Part 3-7: Acceptance and constancy tests – Imaging performance
of X-ray equipment for dental cone beam computed tomography

1 Scope and object
This part of IEC 61223 applies to DENTAL CONE-BEAM COMPUTED TOMOGRAPHY X-RAY EQUIPMENT,
hereafter also called DENTAL CBCT EQUIPMENT, that conforms to IEC 60601-2-
63:2012+AMD1:2017+AMD2:2021.
NOTE 1 DENTAL CBCT EQUIPMENT is a subset of DENTAL EXTRA-ORAL X-RAY EQUIPMENT.
NOTE 2 DENTAL EXTRA-ORAL X-RAY EQUIPMENT can provide one or more of PANORAMIC, CEPHALOMETRIC,
tomosynthesis and DENTAL CBCT imaging modalities, all of which are in the scope of the IEC 60601-2-63 basic safety
and performance standard.
This document applies to ACCEPTANCE TESTS and CONSTANCY TESTS on DENTAL CONE-BEAM
COMPUTED TOMOGRAPHY X-RAY EQUIPMENT.
The aim of ACCEPTANCE TESTS is to verify compliance of the installation or MAJOR SERVICE ACTION
with specifications affecting the image quality, RADIATION OUTPUT and PATIENT positioning.
The requirements specified in this document are minimal requirements. The MANUFACTURER can
establish criteria for the tests described here that exceed the levels contained in this document.
CONSTANCY TESTS are performed to ensure that the functional performance of ME EQUIPMENT
meets established criteria and to enable the early recognition of changes in the properties of
components of the ME EQUIPMENT, and to verify compliance with specifications affecting the
image quality, RADIATION OUTPUT and PATIENT positioning.
This document also contains requirements for the ACCOMPANYING DOCUMENTS associated with
ACCEPTANCE AND CONSTANCY TESTING of the DENTAL CBCT EQUIPMENT.
This document does not apply to:
– aspects of thermal, EMD (electromagnetic disturbances), mechanical and electrical safety;
– aspects of mechanical, electrical and software performance, unless they are essential for
performing the ACCEPTANCE TESTS and CONSTANCY TESTS, and directly affect image quality,
RADIATION OUTPUT and PATIENT positioning.
NOTE 3 Such aspects are generally addressed by IEC 60601-1 (all parts).
Equipment in the scope of IEC 61223-3-5 is excluded from the scope of this document.
DENTAL EXTRA-ORAL X-RAY EQUIPMENT can provide modalities which are in the scope of
IEC 61223-3-4. In this case, the respective clauses of the IEC 61223-3-4 apply.
The object of this document is to establish:
– the essential parameters which describe the performance of DENTAL CBCT EQUIPMENT with
regard to the image quality, RADIATION OUTPUT and PATIENT positioning;
– methods of testing and whether measured quantities related to those parameters comply
with the specified requirements.

These methods rely on non-invasive measurements performed once the installation or a MAJOR
SERVICE ACTION is completed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 60601-1-3:2008, Medical electrical equipment–Part 1-3: General requirements for basic
safety and essential performance – Collateral Standard: Radiation protection in diagnostic X-ray
equipment
IEC 60336, Medical electrical equipment – X-ray tube assemblies for medical diagnosis –
Characteristics of focal spots
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE An index of defined terms is found on page 41.
3.1
BASELINE VALUE
reference value used for constancy testing
Note 1 to entry: BASELINE VALUES are usually established by the completed ACCEPTANCE TEST.
3.2
CONE BEAM COMPUTED TOMOGRAPHY
CBCT
imaging procedure that generates a three-dimensional volumetric representation from the
reconstruction of a number of two-dimensional, digital X-ray images
Note 1 to entry: DENTAL CBCT is a subset of DENTAL VOLUMETRIC RECONSTRUCTION (DVR) – see 201.3.203 of
IEC 60601-2-63:2012.
3.3
ORIGINAL DATASET
result of the transformation of the PROJECTION data into a volumetric dataset, including the
correction of known, reproducible inhomogeneity of the system and reconstruction
Note 1 to entry: The inhomogeneity is also referred to as "fixed-pattern-noise".
3.4
POSITIONING AIDS
feature that enables the correct positioning of the PATIENT
EXAMPLE: Scout view, presentation of the median sagittal plane, lasers, bite block, head holder, chair.

– 10 – IEC 61223-3-7:2021 © IEC 2021
3.5
ARTEFACT
apparent structure, visible in the image, which does not represent a structure within the object
[SOURCE: IEC 61223-3-4:2000, 3.3.1]
3.6
RAY FIELD
X-
surface of the field irradiated by X-rays at the plane of the image receptor, limited by the decay
of the AIR KERMA to 25 % of the value present in the centre of the X-RAY FIELD
3.7
RESOLUTION INDEX 10
SPATIAL FREQUENCY at which the MODULATION TRANSFER FUNCTION takes the 10 % value
Note 1 to entry: MTF 10 term can also be used.
3.8
RESOLUTION INDEX 50
SPATIAL FREQUENCY at which the MODULATION TRANSFER FUNCTION takes the 50 % value
Note 1 to entry: MTF 50 term can also be used.
3.9
ACCEPTANCE INDEX
AI
index that describes the performance of the device in relation to image quality and AIR KERMA
3.10
HOMOGENEITY
H
consistency of voxel values across one tomographic slice of a specified uniformly dense
material
3.11
CONTRAST TO NOISE RATIO
CNR
quantity describing the ability to distinguish the contrast of selected objects in the presence of
noise
3.12
MODULATION TRANSFER FUNCTION
MTF
dimensional estimation of the three-dimensional modulation properties of the system
3.13
ACCEPTANCE TEST
test carried out after new ME EQUIPMENT has been installed, or a MAJOR SERVICE ACTION has
been performed on existing ME EQUIPMENT, in order to verify compliance with MANUFACTURER’s
specifications or established requirements
3.14
CONSTANCY TEST
test carried out periodically in order to verify continued compliance with MANUFACTURER’s
specifications or established requirements

3.15
MAJOR SERVICE ACTION
action that may significantly affect RADIATION OUTPUT, image quality, or PATIENT positioning
EXAMPLE Replacement of the X-RAY GENERATOR, installation of a new BEAM LIMITING DEVICE, installation of a new
image receptor, and reinstalling the DENTAL CBCT equipment.
Note 1 to entry: The MANUFACTURER may provide a list of MAJOR SERVICE ACTIONS.
Note 2 to entry: See IEC 61223-3-5:2019, 3.13.
3.16
DENTAL
related to structures in the dento-maxillo-facial region of the PATIENT, including dentition
[SOURCE: IEC 60601-2-63:2012, 201.3.202]
3.17
DOSE AREA PRODUCT
DAP
product of the area of the cross-section of an X-RAY BEAM and the averaged AIR KERMA over that
cross-section
Note 1 to entry: An alternative term for "DOSE AREA PRODUCT" (DAP) is "AIR KERMA AREA PRODUCT" (KAP) as used in
ICRP 135.
[SOURCE: IEC 60601-2-54:2009, 201.3.203, modified – The abbreviated term "DAP" has been
added, and the unit deleted.]
3.18
RADIATION OUTPUT
AIR KERMA per CURRENT TIME PRODUCT at a given distance from the FOCAL SPOT in the primary
X-RAY BEAM
[SOURCE: IEC 61223-3-4:2000, 3.3.4, modified – The unit has been deleted from the
definition.]
4 General aspects of ACCEPTANCE TESTS and CONSTANCY TESTS
4.1 Preconditions
ACCEPTANCE TESTS shall be performed on EQUIPMENT which has been installed, or received a
MAJOR SERVICE ACTION, according to the ACCOMPANYING DOCUMENTS.
4.2 General conditions to be considered in testing
4.2.1 PHANTOM
The ACCEPTANCE and CONSTANCY TESTS are based on the evaluation of images acquired with
the PHANTOM such as described in the Annex C.
The PHANTOM shall be positioned in such a way that the tests from 5.5 to 5.10 can be performed.
Means for mounting the PHANTOM to the EQUIPMENT shall be made available by the
MANUFACTURER.
The PHANTOM image data shall be acquired and reconstructed using standard parameters
appropriate for a PATIENT. The same parameters established in ACCEPTANCE TESTS shall be used
in CONSTANCY TESTS.
– 12 – IEC 61223-3-7:2021 © IEC 2021
Means for analysing the ORIGINAL DATASET of the PHANTOM shall be made available by the
MANUFACTURER.
NOTE 1 The MANUFACTURER can provide these parameters in the ACCOMPANYING DOCUMENTS.
NOTE 2 For finding issues before use, it is enough to perform this testing at just one volume/setting.
4.2.2 AIR KERMA
The AIR KERMA exposure conditions shall be the same as the parameters used for the PHANTOM
based testing.
4.3 Documents and data for the tests in the ACCOMPANYING DOCUMENTS
Additional requirements for PROCEDURES in ACCOMPANYING DOCUMENTS (which include
instructions for use and technical description) are found in the subclauses listed in Table 1.
The ACCOMPANYING DOCUMENTS shall contain quality control PROCEDURES to be performed on
the ME EQUIPMENT by the RESPONSIBLE ORGANIZATION. These shall include ACCEPTANCE TEST and
CONSTANCY TEST criteria for the tests.
Table 1 – Additional requirements in ACCOMPANYING DOCUMENTS
Title Subclause
Preconditions 4.1
General conditions to be considered in testing 4.2
Establishment of BASELINE VALUES and TEST frequencies 4.6
Visual inspection 5.1
ACCEPTANCE INDEX 5.8
ARTEFACTS 5.10
4.4 Measuring INSTRUMENTS
The DIAGNOSTIC DOSIMETER used for ACCEPTANCE or CONSTANCY TESTS shall be calibrated to
applicable regulatory requirements.
NOTE There might be local regulations regarding calibration requirements.
4.5 MAJOR SERVICE ACTION
After a MAJOR SERVICE ACTION, an ACCEPTANCE TESt shall be performed.
4.6 Record and establishment of BASELINE VALUES and TEST frequencies
The testing conditions and results of performed ACCEPTANCE and CONSTANCY TESTS shall be
recorded. The records shall be maintained by the RESPONSIBLE ORGANISATION.
For the AIR KERMA, CNR and RESOLUTION INDEX 50 tests, the baseline values shall be established
during the ACCEPTANCE TESTS.
The ACCOMPANYING DOCUMENTS shall provide recommended frequencies for CONSTANCY TESTS.
The minimum frequency for CONSTANCY TESTS of CNR, RESOLUTION INDEX 10 and 50,
HOMOGENEITY and geometric accuracy shall be every 6 months. The minimum frequency for
CONSTANCY TESTS of AIR KERMA and alignment of X-RAY FIELD and EFFECTIVE IMAGE RECEPTION
AREA shall be every 5 years.
NOTE It is possible national regulations specify a different frequency of testing.
5 Performance tests for DENTAL CBCT EQUIPMENT
5.1 Visual inspection
The presence of the following declarations shall be checked as part of the visual inspection of
the marking on the outside of the ME EQUIPMENT and ACCOMPANYING DOCUMENTS:
– characteristics such as X-RAY TUBE VOLTAGE (kV), X-RAY TUBE CURRENT (mA), IRRADIATION
TIME (s);
– NOMINAL VALUE of the FOCAL SPOT according to IEC 60336;
– value of the TOTAL FILTRATION according to IEC 60601-1-3.
5.2 Functional test
The following functionality shall be checked:
– positioning aids as described by the MANUFACTURER;
– display of the DOSE AREA PRODUCT.
The functionalities of the system shall be tested according to the procedure provided by the
ACCOMPANYING DOCUMENTS.
NOTE 1 Local regulatory requirements can require specific tests.
NOTE 2 Examples of functional tests can be positioning aids, display devices, mechanical movement supporting
the X-RAY TUBE ASSEMBLY and X-RAY IMAGE RECEPTOR.
5.3 Relationship between X-RAY FIELD and EFFECTIVE IMAGE RECEPTION AREA
5.3.1 Requirement
The X-RAY FIELD shall not over-radiate the EFFECTIVE IMAGE RECEPTION AREA at the surface of
the X-RAY IMAGE RECEPTOR more than 2 % of the FOCAL SPOT TO IMAGE RECEPTOR DISTANCE in
one direction or at most 3 % in both directions. In the case of the X-RAY IMAGE RECEPTOR having
an active surface side length below 8 cm, the over-RADIATION shall not be larger than 1 % of the
FOCAL SPOT TO IMAGE RECEPTOR DISTANCE in one direction or at most 2 % in two directions.
5.3.2 Test
The dimensions of a rectangular X-RAY FIELD are described in terms of the length of its intercepts
on each of two orthogonal major axes in the plane of interest.
For circular X-RAY FIELD, the dimensions are described accordingly, replacing the lengths of the
intercepts with the diameter.
The maximum size available of the X-RAY FIELD is determined by examination of at least one
appropriate image from the DENTAL CBCT EQUIPMENT or use of a test instrument at the location
of the X-RAY IMAGE RECEPTOR and compared with the EFFECTIVE IMAGE RECEPTION AREA.
NOTE Examples of test verification methods can be: the presentation of an image from the DENTAL CBCT EQUIPMENT
with collimation edges visible or measurement with a device that can detect the boundary of a RADIATION field.
5.4 Reproducibility of the AIR KERMA
5.4.1 Requirement
The deviation of any individual measurement from a set from at least three measurements of
incident AIR KERMA K from their mean K shall not exceed ±5 %.
d d
– 14 – IEC 61223-3-7:2021 © IEC 2021
NOTE The measurement of incident AIR KERMA can be performed with a DIAGNOSTIC DOSEMETER shielded from
backscatter. Alternatively, the measurement of a DIAGNOSTIC DOSEMETER sensitive to backscatter can be corrected
by the appropriate factor.
The value of at installation shall serve as a BASELINE VALUE.
K
d
For the CONSTANCY TEST, the value K shall not differ by more than ±20 % from the BASE LINE
d
VALUE .
K
d
5.4.2 Test
The measurements shall be obtained at the closest accessible surface to the IMAGE RECEPTION
PLANE without modification of the housing with standard parameters appropriate for a PATIENT
including X-RAY TUBE VOLTAGE, X-RAY TUBE CURRENT, IRRADIATION TIME and FILTRATION. The same
parameters established in ACCEPTANCE TESTS shall be used in CONSTANCY TESTS.
5.5 Geometric accuracy
5.5.1 General
The structures included in the PHANTOM are resolved differently in images from different
systems. With the help of known dimensions of appropriate structures within the PHANTOM, the
maximum resolution, which is limited by the reconstruction, can be determined.
5.5.2 Requirement
The value of measured voxel size is compared with the specifications of the MANUFACTURER.
The value shall lie within the tolerance range indicated by the MANUFACTURER.
5.5.3 Test
A structure of the PHANTOM having a length b of at least 5 mm in the direction of either the pixel
rows or columns is chosen in the dataset of one axial slice. The number of pixels p
corresponding to b is determined. The voxel size is given by Formula (1):
b
σ = (1)
f
p
NOTE 1 This test item also serves to monitor the correct length measurement of structures in axial slices.
b
NOTE 2 The ratio  refers to the deviation of a measurement in the image to a known physical dimension.
p
5.6 * Spatial resolution
5.6.1 General
The capacity of the system to image fine-structured objects with a corresponding CONTRAST is
evaluated by RESOLUTION INDEXES. These indexes are derived from the MODULATION TRANSFER
FUNCTION (MTF).
MODULATION TRANSFER FUNCTION is calculated using one of two procedures described in
The
Annex D.
5.6.2 Requirement
The RESOLUTION INDEX 50 shall be recorded as a result of the ACCEPTANCE TEST and shall serve
as a BASELINE VALUE for CONSTANCY TEST. The MEASURED VALUE resulting from the CONSTANCY
TEST shall not be less than 60 % of the BASELINE VALUE.

The RESOLUTION INDEX 10 shall be larger than 1 lp/mm unless ano
...