EN 62464-1:2007

SLOVENSKI STANDARD
01-september-2010
Oprema za magnetno resonanco za medicinsko slikanje - 1. del: Ugotavljanje
bistvenih parametrov za kakovost slike (IEC 62464-1:2007)
Magnetic resonance equipment for medical imaging - Part 1: Determination of essential
image quality parameters (IEC 62464-1:2007)
Magnetresonanzgeräte für die medizinische Bildgebung - Teil 1: Bestimmung der
wesentlichen Bildqualitätsparameter (IEC 62464-1:2007)
Appareils à résonance magnétique pour imagerie médicale - Partie 1: Détermination des
principaux paramètres de qualité d’image (CEI 62464-1:2007)
Ta slovenski standard je istoveten z: EN 62464-1:2007
ICS:
11.040.50 Radiografska oprema Radiographic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62464-1
NORME EUROPÉENNE
May 2007
EUROPÄISCHE NORM
ICS 11.040.50
English version
Magnetic resonance equipment for medical imaging -
Part 1: Determination of essential image quality parameters
(IEC 62464-1:2007)
Appareils à résonance magnétique  Magnetresonanzgeräte
pour imagerie médicale - für die medizinische Bildgebung -
Partie 1: Détermination des principaux Teil 1: Bestimmung der wesentlichen
paramètres de qualité d’image Bildqualitätsparameter
(IEC 62464-1:2007)
(CEI 62464-1:2007)
This European Standard was approved by CENELEC on 2007-04-01. 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

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62464-1:2007 E
Foreword
The text of document 62B/641/FDIS, future edition 1 of IEC 62464-1, 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 62464-1 on 2007-04-01.
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) 2008-01-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-04-01
In this standard, the following print types are used:
– requirements, compliance with which can be tested, and definitions: roman type;
– explanations, advice, notes, general statements and exceptions: smaller roman type;
– test specifications: italic type;
– terms defined in Clause 3 of EN 60601-1:2006, in this standard or in IEC/TR 60788: SMALL CAPITALS.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62464-1:2007 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 60601-1 NOTE  Harmonized as EN 60601-1:2006 (not modified).
IEC 60601-1-2 NOTE  Harmonized as EN 60601-1-2:2001 (not modified).
IEC 60601-2-33 NOTE  Harmonized as EN 60601-2-33:2002 (not modified).
IEC 61223-2-6 NOTE  Harmonized as EN 61223-2-6:2007 (not modified).
__________
- 3 - EN 62464-1:2007
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)
IEC/TR 60788 - Medical electrical equipment - Glossary of - -
defined terms
1)
Undated reference.
NORME CEI
INTERNATIONALE
IEC
62464-1
INTERNATIONAL
Première édition
STANDARD
First edition
2007-01
Appareils à résonance magnétique
pour imagerie médicale –
Partie 1:
Détermination des principaux paramètres
de qualité d'image
Magnetic resonance equipment
for medical imaging –
Part 1: Determination of essential image
quality parameters
© IEC 2007 Droits de reproduction réservés ⎯ Copyright - all rights reserved
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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.
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МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

62464-1 © IEC:2007 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11

1 Scope.13
2 Normative references .15
3 Terms, definitions and symbols .15
3.1 Terms and definitions .15
3.2 Symbols .23
4 Procedures for the determination of essential image parameters .35
4.1 General requirements for all procedures.35
4.2 SIGNAL TO NOISE RATIO .37
4.3 UNIFORMITY.43
4.4 SLICE THICKNESS in 2-D scanning .49
4.5 Two-dimensional GEOMETRIC DISTORTION.59
4.6 SPATIAL RESOLUTION.67
4.7 GHOSTING ARTEFACTS .73
5 CONSTANCY TEST.79
5.1 Objectives and rational.79
5.2 Requirements for the TEST DEVICE.81
5.3 Scan characteristics .81
5.4 Measurement procedure.81
5.5 Data analysis, reporting of results and tolerances .83

Annex A (normative) Alternative methods .85
Annex B (informative) Rationales.113

Bibliography.150
Index of defined terms .155

Figure 1 – Insertion of a homogenous TEST DEVICE into the RF COIL .45
Figure 2 – Position of the TEST DEVICE on the surface coil .45
Figure 3 – Signal intensity profile in the inclined slab method .51
Figure 4 – Correcting for rotation of TEST DEVICE .55
Figure 5 – TEST DEVICE example for a spherical SPECIFICATION VOLUME, consisting of a
polypropylene carboy (Perspex) cylinder whose internal wall defines the ROI perimeter .61
Figure 6 – TEST DEVICE example for a spherical SPECIFICATION VOLUME, consisting of a
number of vials distributed on the ROI perimeter.61
Figure 7 – Two lines passing through the centre of the TEST DEVICE .63
Figure 8 – Distances to be determined.65
Figure 9 – Periodic pattern.69
Figure 10 – Image of periodic pattern and position of ROI.71

62464-1 © IEC:2007 – 5 –
Figure 11 – TEST DEVICE (circular object), ghosts (crescents),
and REGION OF INTEREST (ROI) measurement boxes for mean signal, ghost,
and noise measurements .77
Figure A.1 – Wedge TEST DEVICE.95
Figure A.2 – Measurement of SLICE PROFILE and SLICE THICKNESS using wedge TEST
DEVICE .97
Figure B.1 – Relaxation times T and T in dependency on the
1 2
concentration of CuSO × 5 H 0 .117
4 2
Figure B.2 – Centring error .137

Table B.1 – TEST DEVICE conductivity and dielectric properties. 121
Table B.2 – Comparison of company bandwidths .129
Table B.3 – Relaxation fit parameters for Gd[TMHD] concentrations ≤4 parts per
thousand by weight.131

62464-1 © IEC:2007 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC RESONANCE EQUIPMENT FOR MEDICAL IMAGING –

Part 1: Determination of essential image quality parameters

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 62464-1 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/641/FDIS 62B/646/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.

62464-1 © IEC:2007 – 9 –
In this standard, the following print types are used:
– requirements, compliance with which can be tested, and definitions: roman type;
– explanations, advice, notes, general statements and exceptions: smaller roman type;
– test specifications: italic type;
– terms defined in clause 2 of the General Standard, in this standard or in IEC 60788:
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.
62464-1 © IEC:2007 – 11 –
INTRODUCTION
This international standard is written at a moment in which MAGNETIC RESONANCE EQUIPMENT is
already present in the market place for more than 20 years. It is estimated that more then
20 000 scanners are operational and more than 0,5 billion PATIENTS have been scanned. A
number of standards on quality assurance and quality control have been developed by
national committees to address the need for quantitative addressing of system performance
and system maintenance. It is therefore felt to be necessary to introduce this IEC standard in
addition to the existing standard on MAGNETIC RESONANCE (MR) safety, because the IEC
standards have a true international character and this IEC standard is the first start to process
and combine current best practices together and provide guidance on how to address the
various questions on quality control and quality assurance testing of MAGNETIC RESONANCE
EQUIPMENT together. Having a standardized set of test methods minimizes the amount of work
for the MR MANUFACTURERS to demonstrate the performance characteristics of the MR
scanners for many different countries and in addition, these countries do not have to
formulate their own requirements for the performance testing.
Since MR scanners have been around for some time, this international standard is an attempt
to consolidate the current way of working for the quality control of the performance
characteristics concerning essential image quality parameters, and does not introduce major
new development efforts for the established MR equipment to fulfil the requirements of this
standard. This objective is achieved by introducing preferred methods in the main text of the
standard, while allowing acceptable alternative test methods, described in Annex A of the
standard. A number of the ACCEPTANCE TEST methods described in the standard have already
been described earlier, mainly as NEMA technical MR standards, while new methods have
been developed since then. For this standard, it is attempted to select the best method as the
preferred method, although for a number of specific tests good alternatives are available and
are therefore also acceptable.
Also for the quality assurance tests and the CONSTANCY TESTS, each MANUFACTURER has
developed its own test device and related test procedures and data analysis in the past years.
For the CONSTANCY TESTS it was therefore decided not to describe detailed test methods but
only prescribe the parameters to be measured and essential conditions for these
measurements in the main standard. This provides the necessary latitude to account for the
many unique MR designs (extremity scanners, whole body scanners, cylindrical versus open
scanners, various field strengths, phantom design, data analysis) and examples for possible
CONSTANCY TESTS for the required parameters in the annex. This allows the user to use as
many of the tools supplied by MR MANUFACTURERS as possible, appropriate and useful and
still fulfill the requirements for quality control and quality assurance.

62464-1 © IEC:2007 – 13 –
MAGNETIC RESONANCE EQUIPMENT FOR MEDICAL IMAGING –

Part 1: Determination of essential image quality parameters

1 Scope
This international standard specifies measurement procedures for the determination of many
essential medical MR EQUIPMENT image quality parameters. Measurement procedures as
addressed in this standard are suitable for:
- quality assessment in the ACCEPTANCE TEST;
- quality assurance in the CONSTANCY TEST.
In addition, the measurement procedures specified in this standard may also be useful for
type tests, although that is not an objective of this standard.
This standard does not address:
- required levels of performance for ACCEPTANCE TEST and CONSTANCY TEST;
- image quality assessment of high field MR EQUIPMENT greater than 4 T, if not otherwise
stated;
- image quality affected by MR-compatibility issues;
- special diagnostic procedures such as flow imaging, perfusion, diffusion, radiotherapy and
image-guided therapy applications;
- type tests.
The scope of this standard is also limited to measuring image quality characteristics in TEST
DEVICES, not in PATIENT images.
The measurement procedures specified in this standard are directed to:
a) MANUFACTURERS, who can demonstrate compliance by performing acceptance and
constancy methods as described by this standard,
b) test houses, which can confirm performance of MR EQUIPMENT using methods described in
this standard,
c) regulatory authorities, who can reference this standard, and
d) RESPONSIBLE ORGANISATIONS who want to perform ACCEPTANCE and CONSTANCY TESTS
using methods described in this standard.
The essential image quality parameters and measurement methodologies defined in this
standard are:
- SIGNAL-TO-NOISE RATIO,
- UNIFORMITY,
- SLICE THICKNESS and SLICE PROFILE,
- GEOMETRIC DISTORTION,
- SPATIAL RESOLUTION, and
- ghosting.
62464-1 © IEC:2007 – 15 –
This standard describes the preferred measurement procedures. It also describes alternative
methods in Annex A. The preferred test methods may be substituted with the alternative
methods. If necessary, other methods not described in this standard may be used, provided
these other test methods are documented and validated against the methods described in the
standard. Validation of other test methods requires an analysis of test sensitivity to the same
parameter of interest and an analysis of the insensitivity of the test to other unrelated
parameters and should demonstrate a similar, or better, level of sensitivity to the same
parameter of interest and a similar, or better, level of robustness against unrelated
parameters. All methods shall produce quantitative results.
The rationale to the preferred and alternate methods, and their pitfalls, are described in
Annex B.
This standard also presents requirements for CONSTANCY TESTS suitable for MR EQUIPMENT
quality assurance programs concerning essential image quality parameters. There are no
preferred CONSTANCY TEST methods, to provide flexibility in using existing automated
procedures where available, but suggested examples of test methods are found in Annex A. If
necessary, other CONSTANCY TEST methods not described in this standard may be used. Since
the needs of RESPONSIBLE ORGANISATIONS' quality assurance programs may vary, RESPONSIBLE
ORGANISATIONS are encouraged to determine the necessary scope of tests, quality of the
tests, and the sensitivity of the data analysis etc. This standard places an emphasis on
consistently repeatable, automated measuring tools that facilitate trend analysis and the
frequent quick testing of a small set of important parameters which are sensitive to the overall
operating characteristics of the MR EQUIPMENT.
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 60788, Medical electrical equipment – Glossary of defined terms
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
acceptance test
test carried out after new EQUIPMENT has been installed, or major modifications have been
made to existing EQUIPMENT, in order to verify compliance with contractual specifications
[IEC 61223-1, definition 3.2.4]

62464-1 © IEC:2007 – 17 –
3.1.2
accompanying document
document accompanying ME EQUIPMENT, an ME SYSTEM, EQUIPMENT or an ACCESSORY and
containing information for the RESPONSIBLE ORGANIZATION or OPERATOR, particularly regarding
BASIC SAFETY and ESSENTIAL PERFORMANCE
[IEC 60601-1:2005, definition 3.4]
3.1.3
artefact
apparent structure visible in the image that does not represent a structure at the
corresponding position within the object and that cannot be explained by noise
3.1.4
bandwidth per pixel
reciprocal of the duration of the sampling window
NOTE Instead of BANDWIDTH PER PIXEL, equivalent values may be stated on the control console.
3.1.5
body test device
TEST DEVICE representing the PATIENT’S body
3.1.6
constancy test
each of a series of tests, carried out:
– to ensure that the functional performance of EQUIPMENT meets ESTABLISHED CRITERIA; or
– to enable the early recognition of changes in the properties of components of the
EQUIPMENT.
[IEC 61223-1:1993, definition 3.2.6]
3.1.7
extremity test device
TEST DEVICE representing the PATIENT’s extremities
3.1.8
field of view
FOV
size of the imaging area requested by OPERATOR
NOTE To be specified with one or two linear measures (in mm), if imaging area is square or rectangular
respectively.
3.1.9
geometric distortion
spatial position deviation of the imaged structure from expected position of real object
structure
3.1.10
ghosting artefact
ARTEFACT showing a replica or part of the replica of an existing structure in a wrong position
3.1.11
head test device
TEST DEVICE representing the PATIENT’s head

62464-1 © IEC:2007 – 19 –
3.1.12
image data
reconstructed acquisition data
3.1.13
image noise
random fluctuations from the expected signal values in an image
3.1.14
intended use/intended purpose
use of a product, process or service in accordance with the specifications, instructions and
information provided by the MANUFACTURER
[IEC 60601-1:2005, definition 3.44]
3.1.15
isocentre
in MR EQUIPMENT null point of the spatially encoding gradients
NOTE Typically, this also corresponds to the region of highest magnet homogeneity.
3.1.16
magnetic resonance equipment
MR equipment
MEDICAL ELECTRICAL EQUIPMENT that is intended for in-vivo MAGNETIC RESONANCE EXAMINATION
of a PATIENT. The MR EQUIPMENT comprises all parts in hardware and software from the SUPPLY
to the display monitor. The MR EQUIPMENT is a Programmable Electrical Medical System
MAINS
(PEMS)
[IEC 60601-2-33:2002, definition 2.2.101]
3.1.17
magnetic resonance system
MR system
ensemble of MR EQUIPMENT, ACCESSORIES including means for display, control, energy
supplies, and the CONTROLLED ACCESS AREA, where provided
[IEC 60601-2-33:2002, definition 2.2.102]
3.1.18
manufacturer
natural or legal person with responsibility for the design, manufacture, packaging, or labelling
of ME EQUIPMENT, assembling an ME SYSTEM, or adapting ME EQUIPMENT or an ME SYSTEM,
regardless of whether these operations are performed by that person or on that person's
behalf by a third party
[IEC 60601-1:2005, definition 3.55]
3.1.19
operator
person handling EQUIPMENT
[IEC 60601-1:2005, definition 3.73]
3.1.20
radio frequency coil
RF coil
coil or probe used to transmit and/or receive radio frequency electromagnetic fields

62464-1 © IEC:2007 – 21 –
3.1.21
reconstruction parameters
in MR EQUIPMENT ensemble of all parameters that uniquely define the transform of the digitized
signals to an image
3.1.22
reference position
predefined point within the SPECIFICATION VOLUME
NOTE Normally the REFERENCE POSITION lies on the symmetry axis of the coil and corresponds to the centre of
gravity of the SPECIFICATION VOLUME.
3.1.23
region of interest
ROI
localized part of an image, which is of particular interest at a given time
[IEC 61223-2-6, definition 3.3.9]
3.1.24
responsible organisation
entity accountable for the use and maintenance of an ME EQUIPMENT or an ME SYSTEM
NOTE 1 The accountable entity can be, for example, a hospital, an individual clinician or a layperson. In home
use applications, the PATIENT, OPERATOR and RESPONSIBLE ORGANIZATION can be one and the same
person.
NOTE 2 Education and training is included in “use.”
[IEC 60601-1:2005, definition 3.101]
3.1.25
signal to noise ratio
SNR
the quotient of the signal level divided by the noise level
3.1.26
slice profile
in MR EQUIPMENT, plot of the MAGNETIC RESONANCE signal intensity perpendicular to the
scanned slice
3.1.27
slice thickness
in MR EQUIPMENT, FULL WIDTH AT HALF MAXIMUM (FWHM) of the SLICE PROFILE
3.1.28
spatial resolution
in MR EQUIPMENT, one half of the inverse of the highest spatial frequency where the magnitude
of the MODULATION TRANSFER FUNCTION (MTF) exceeds a required threshold
3.1.29
specification area
in MR EQUIPMENT the intersection of the SPECIFICATION VOLUME and the image plane

62464-1 © IEC:2007 – 23 –
3.1.30
specification volume
in MR EQUIPMENT, imaging volume within which a MANUFACTURER guarantees image
performance specifications
NOTE Images or portions of images outside this volume will not necessarily meet performance specifications, but
can still be useful for diagnostic purposes.
3.1.31
test device
object for imaging test purposes
3.1.32
uniformity
spatial constancy of intensity in the image of a homogeneous TEST DEVICE excluding the effect
of noise or finite data collection (truncation ARTEFACT)
3.2 Symbols
For the purposes of this document, the following symbols apply.
3.2.1
a
width of the plates
3.2.2
AAD
average absolute deviation of pixel signal values
3.2.3
b
length of plates
3.2.4
|b(y)|
magnitude image of a periodic box function
3.2.5
b , b , b , and b
0 1 2 3
curve fit constants
3.2.6
B
static magnetic field
3.2.7
B
radio frequency magnetic field
3.2.8
BW
BANDWIDTH
3.2.9
BWpix
BANDWIDTH PER PIXEL
62464-1 © IEC:2007 – 25 –
3.2.10
BWim
Bandwidth of the image
3.2.11
BWGE
bandwidth defined by GE
3.2.12
BWSiemens
bandwidth defined by Siemens
3.2.13
C
mean pixel signal value of a ROI in the centre of the image
3.2.14
d
p
distance between adjacent plates
3.2.15
d
TEST DEVICE diameter
3.2.16
m
d
diameter of the spherical TEST DEVICE measured in the image
3.2.17
D(X )
i
stretched SLICE PROFILE
3.2.18
ESF(x)
edge spread function
3.2.19
F(ν)
Fourier transform of a box function
3.2.20
FT{}
Fourier transform
3.2.21
FWHM
full width half maximum
3.2.22
g(x)
periodic box function
3.2.23
G(t)
B -field gradient
62464-1 © IEC:2007 – 27 –
3.2.24
G
rd, ph, sel
B -field gradient in read, phase-encoding and slice-selection direction
3.2.25
I
G
intensity of ghost signal
3.2.26
I
N
noise level
3.2.27
L
periodicity of plates
3.2.28
LSF(x)
line spread function
3.2.29
m(ν)
modulation at the spatial frequency ν
3.2.30
MTF(ν)
modulation transfer function
3.2.31
n
number of plates
3.2.32
N
the total number of pixels in the ROI
3.2.33
N
d
number of radial measured distances
3.2.34
Ntot
number of pixels within the histogram ROI which have a pixel value larger than T
3.2.35
NU
non-uniformity
3.2.36
P
slab thickness parallel to the slice
3.2.37
R
TEST DEVICE radius
62464-1 © IEC:2007 – 29 –
3.2.38
RD
relative GEOMETRIC DISTORTION
3.2.39
r
max
maximum GEOMETRIC DISTORTION
3.2.40
r
mean value of the N radial measured distances
3.2.41
r
r
distance of the pixel from the magnet centre
3.2.42
S
sides of trapezoid
3.2.43
S
mean pixel signal value
3.2.44
S
i
individual pixel signal value
3.2.45
S(X )
i
pixel signal value at location X
i
3.2.46
S
echo
signal intensities for the ‘regular echo’
3.2.47
S
stim.echo
signal intensities for the ‘stimulated echo’
3.2.48
SD
standard deviation of pixel signal values
3.2.49
T
threshold value
3.2.50
T
longitudinal relaxation time
3.2.51
T
transversal relaxation time
62464-1 © IEC:2007 – 31 –
3.2.52
T
E
echo time
3.2.53
T
R
repetition time
3.2.54
T
RF
duration of RF-pulse
3.2.55
U
UNIFORMITY
3.2.56
V
threshold used for colour coding
3.2.57
w(x,y,z)
relative weighting function of the signal intensity at the location (x,y,z)
3.2.58
w
i
SLICE THICKNESS measured at measurement i
3.2.59
w
d
weighting factor to remove the effect of discrete differentiation
3.2.60
WFS
water-fat shift
3.2.61
X
i
location
3.2.62
α
flip angle
3.2.63
α
s
slab inclination angle
3.2.64
γ
gyromagnetic ratio
3.2.65
δ
scale GEOMETRIC DISTORTION
62464-1 © IEC:2007 – 33 –
3.2.66
'
δ
effective scale geometric distortion
3.2.67
Δ ()P
i
geometric error caused by choosing the measurement points not precisely on the ROI
perimeter
3.2.68
Δ ()ε
i
geometric error caused by centring error
3.2.69
Δ ()δ
i
geometric error contribution of the geometric distortion
3.2.70
r
ΔB ( r )
static field inhomogeneity at the location of the pixel
3.2.71
Δf
frequency difference
3.2.72
r
ΔG ( r )
B -field gradient linearity error at the location of the pixel
3.2.73
r
Δr ( r )
geometrical shift of the pixel
3.2.74
ΔT
time delay
3.2.75
Δx
pixel size in x dimension
3.2.76
Δy
pixel size in y dimension
3.2.77
ε
centering error
3.2.78
θ
angle of rotation of the TEST DEVICE about the y axis

62464-1 © IEC:2007 – 35 –
3.2.79
θ
r
angle between r and x-axis
3.2.80
σ
δ
aberration GEOMETRIC DISTORTION
3.2.81
ν
spatial frequency
3.2.82
ν
c
cut off frequency
3.2.83
ν
N
Nyquist frequency
3.2.84
φ
constant phase of the signals
4 Procedures for the determination of essential image parameters
4.1 General requirements for all procedures
4.1.1 Requirements for the TEST DEVICE
The TEST DEVICE shall consist of a volume (e.g. polypropylene carboy, Perspex) of appropriate
shape and size to fit inside the receive coil to be tested. It shall be filled with a MR signal-
producing material, (e.g. water, or silicon oil) with a sufficiently small dielectric constant and
conductivity to reduce standing wave phenomena.
The MR specific properties of the signal-producing material (spin density ρ, T , T ) shall be
1 2
similar to that of a PATIENT’s body. (Typical values: T < 1 200 ms, T > 50 ms, Spin density
1 2
ρ = ρ ± 20 %). This can be achieved by doping pure water with appropriate relaxation
H20
modifiers (paramagnetic ions). It is suggested to use values similar to the PATIENT’S body and
avoid extreme values. The TEST DEVICE temperature shall be 22 °C ± 4 °C.
Exceptions to these requirements are specified where necessary.
4.1.2 Requirements for image reconstruction
All images shall be processed with the MR EQUIPMENT’s standard clinical reconstruction
algorithm. All such filters that can be selected by the OPERATOR shall be disabled unless
otherwise specified. Filters include distortion corrections, smoothing and edge enhancement,
for example. If this is not possible, identify all remaining filters in the results. The images to
be analysed shall be substantially free of image ARTEFACTS.

62464-1 © IEC:2007 – 37 –
Exceptions to these requirements are specified where necessary.
4.1.3 Requirements for scanning
All image acquisitions shall be preceded by the standard clinical prescan calibration, unless
otherwise specified.
4.2 SIGNAL TO NOISE RATIO
4.2.1 Objectives and rational
Image SNR is a parameter that relates to clinical usefulness of MRI and also is a sensitive
measure of hardware performance. Experience has shown that variations in system
calibration, gain, coil tuning, RF shielding, or other similar parameters are usually
demonstrated by a corresponding change in image SNR.
It is also a further objective of the SNR, SLICE THICKNESS and SPATIAL RESOLUTION tests to use
the identical sequence and parameters, with some specific exceptions for the number of
averages, to control the close relationship between the results of these three tests.
4.2.2 Requirements for the TEST DEVICE
In order to approximate the IMAGE NOISE performance that would be typically encountered in a
clinical situation, the receive coil of interest shall be electrically loaded to approximate a
50 kg – 90 kg human. Loading may be accomplished by TEST DEVICES or other reproducible
means. Experimentally verify that the loading is similar to a 50 kg – 90 kg human properly
positioned for clinical scanning. The load is considered to be equivalent if the following
electrical parameters match within the stated errors.
– Coil 3 dB bandwidth: ±15 %
– Coil impedance: ±20 % magnitude, ±20º phase
– Coil centre frequency shift: ±1 % of centre frequency
Alternatively, or additionally, other methods (total RF power needed to achieve a certain flip
angle, etc.) can be used to verify the compliance of the loading with a 50 kg – 90 kg human.
BODY TEST DEVICE containing the signal-producing material can be a cylinder, sphere or
The
an ellipsoid. The minimum cross sectional area is a 200 mm diameter circle.
The HEAD TEST DEVICE containing the signal-producing material can be a cylinder, sphere or
an ellipsoid. The minimum cross sectional area is a 150 mm diameter circle.
The EXTREMITY TEST DEVICE containing the signal-producing material can assume any shape.
The minimum cross sectional area will be 85 % of the SPECIFICATION AREA.
4.2.3 Scan parameters
The following sequence should be used:
• 2D single spin echo, single slice sequence centred at ISOCENTRE +/- 30 mm,
• scan plane: transverse, sagittal, coronal (in turn),

62464-1 © IEC:2007 – 39 –
• T = 1 000 ms or ≥3 T of the signal-producing material whichever is larger,
R 1
• T = 30 ms or ≤1/3 T of the signal-producing material whichever is smaller,
E 2
• pixel bandwidth (100 ± 3) Hz,
• FIELD OF VIEW 250 mm for head coil,
• FIELD OF VIEW 440 mm for body coil,
• FIELD OF VIEW of 250 mm for the head coil, FIELD OF VIEW of 440 mm for the body coil, for
all other coils FIELD OF VIEW shall not exceed 110 % of the largest RF COIL dimension in
the image plane,
• matrix 256 × 256,
• SLICE THICKNESS 5 mm, and
• no signal averaging is permitted.
Use the identical sequence and RECONSTRUCTION PARAMETERS for SLICE THICKNESS and
SPATIAL RESOLUTION measurements, apart signal averaging is permitted.
4.2.4 Measurement procedure
The placement of the TEST DEVICE in the RF COIL shall simulate the typical diagnostic
procedure.
Wait appropriate time (e.g. 15 min for a large TEST DEVICE) after positioning the TEST DEVICE
before scanning to prevent swirling ARTEFACTS. The scanned slice shall be set through the
REFERENCE POSITION to give the largest SPECIFICATION AREA; preferably along or perpendicular
to a symmetry axis of the coil.
Execute two sequential scans (image 1 and image 2) of the slice with less than 5 min from the
end of the first scan to the beginning of the second. No adjustment or calibration shall be
performed between the scans. Verify the SPATIAL RESOLUTION and SLICE THICKNESS for the
sequence in SNR determination. Use the methods described in 4.4 and 4.6 of this standard.
NOTE This verification confirms that the nominal SLICE THICKNESS and SPATIAL RESOLUTION were realised.
4.2.5 Data analysis and tolerances
The REGION OF INTEREST (ROI) has to be a centred, regular geometric area enclosing at least
85 % of the area of the image of the signal-producing volume of the TEST DEVICE.
Step 1: Determine the mean pixel value within the ROI in image 1. The resulting number
(minus any baseline pixel offset value) shall be called the image signal, S.
Step 2: Calculate a pixel by pixel signed difference image (image 3) as follows:
image 3 = image 1 - image 2.
The subtraction process shall avoid errors resulting from the generation of pixel values that
exceed the minimum (or maximum) pixel values allowed on the particular MR EQUIPMENT (i.e.
negative values).
Step 3: Transfer the ROI used to measure S in step 1 to the same location in image 3 and
compute the ROI standard deviation (SD). Divide SD by the square root of two, eliminating
the noise amplification of the image subtraction process, to give the IMAGE NOISE.

62464-1 © IEC:2007 – 41 –
Step 4. Calculate SNR as:
S
SNR =                                        (1)
⎛ SD⎞
⎜ ⎟
⎜ ⎟
⎝ ⎠
4.2.6 Reporting of results
The report shall contain the following:

Parameter Dimension
SNR
SLICE THICKNESS (result of measurement according to 4.4) mm
SPATIAL RESOLUTION (result of measurement according to 4.6) mm
Scan plane orientation
Direction of frequency/phase encoding
SPECIFICATION AREA - size and shape mm
Coil dimensions mm
Coil name and type
Cross-sectional area of TEST DEVICE - size and shape mm²
ROI - size and shape mm²
REFERENCE POSITION
Data acquisition matrix size
FIELD OF VIEW mm²
mm
Nominal voxel dimension (Δx, Δy, selected SLICE THICKNESS)
SLICE THICKNESS (measured) mm
SPATIAL RESOLUTION (measured) mm
TEST DEVICE filler material description
TEST DEVICE filler T ms
TEST DEVICE filler T ms
TEST DEVICE salt type and concentration g/l
BANDWIDTH PER PIXEL Hz/pixel
Sequence repetition time (T) ms
R
Echo delay time (T) ms
E
Number of averages
Pulse sequence spin echo or gradient echo
Filter used (if any)
The results shall be accompanied by an estimate of the measurement
errors.
List all RECONSTRUCTION PARAMETERS selected and provide other relevant information that
ensures repeatability.
62464-1 © IEC:2007 – 43 –
4.3 UNIFORMITY
4.3.1 Objectives and rationale
This subclause presents a measurement procedure for computing a UNIFORMITY figure of merit
that is suitable for all MR coils. As a result the low spatial frequency non-uniformities typical
for MRI images can be characterized. The measurements are made over a volume that is
representative of the region used for
...