Medical electrical equipment - Medical image display systems - Part 1: Evaluation methods

IEC 62563-1:2009 describes the evaluation methods for testing medical image display systems. It is directed to practical tests that can be visually evaluated or measured using basic test equipment. More advanced or more quantitative measurements can be performed on these devices, but these are beyond the scope of this document. IEC 62563-1:2009 applies to medical image display systems, which can display monochrome image information in the form of greyscale values on colour and greyscale image display systems (e.g. cathode ray tube (CRT) monitors, flat panel displays, projection system). This standard applies to medical image display systems used for diagnostic (interpretation of medical images toward rendering clinical diagnosis) or viewing (viewing medical images for medical purposes other than for providing a medical interpretation) purposes and therefore having specific requirements in terms of image quality. Head mounted image display systems and image display systems used for confirming positioning and for operation of the system are not covered by this standard.

Appareils électromédicaux - Systèmes d'imagerie médicale - Partie 1: Méthodes d'évaluation

La CEI 62563-1:2009 décrit les méthodes d'évaluation utilisées pour les essais des systèmes d'imagerie médicale. Elle est destinée aux essais pratiques pouvant faire l'objet d'une évaluation ou d'une mesure visuelle en utilisant un appareillage d'essai de base. Des mesures plus approfondies ou plus quantitatives peuvent être effectuées sur ces dispositifs, ces mesures ne relevant toutefois pas du domaine d'application du présent document. La CEI 62563-1:2009 s'applique aux systèmes d'imagerie médicale qui peuvent afficher des informations sous forme d'images monochromes selon des valeurs d'échelle des gris sur des systèmes d'imagerie couleur et à échelle des gris (par exemple moniteurs a tubes cathodiques, écrans plats, système de projection). La présente norme s'applique aux systèmes d'imagerie médicale utilisés à des fins de diagnostic (interprétation des images médicales en vue d'un diagnostic clinique) ou d'observation (visualisation d'images médicales dans le cadre d'interventions autres que celles destinées à une interprétation médicale), auxquels sont par conséquent associées des exigences spécifiques en termes de qualité de l'image. Les systèmes d'imagerie de tête et les systèmes d'imagerie utilisés pour confirmer le positionnement et pour l'exploitation du système ne sont pas couverts par la présente norme.

General Information

Status
Published
Publication Date
09-Dec-2009
Current Stage
PPUB - Publication issued
Start Date
10-Dec-2009
Completion Date
10-Dec-2009
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IEC 62563-1
Edition 1.0 2009-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Medical electrical equipment – Medical image display systems –
Part 1: Evaluation methods
Appareils électromédicaux – Systèmes d’imagerie médicale –
Partie 1: Méthodes d’évaluation
IEC 62563-1:2009
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 62563-1
Edition 1.0 2009-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Medical electrical equipment – Medical image display systems –
Part 1: Evaluation methods
Appareils électromédicaux – Systèmes d’imagerie médicale –
Partie 1: Méthodes d’évaluation
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX
ICS 11.040.55 ISBN 978-2-88910-764-3
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 62563-1 © IEC:2009
CONTENTS

FOREWORD...........................................................................................................................4

INTRODUCTION.....................................................................................................................6

1 Scope...............................................................................................................................7

2 Normative references .......................................................................................................7

3 Terms, definitions, symbols and abbreviations..................................................................7

3.1 Terms and definitions ..............................................................................................7

3.2 Symbols ................................................................................................................10

3.3 Abbreviations ........................................................................................................11

4 General ..........................................................................................................................11

5 Prerequisites ..................................................................................................................11

6 Equipment and tools.......................................................................................................12

6.1 LUMINANCE meter ...................................................................................................12

6.2 ILLUMINANCE meter.................................................................................................12

6.3 Colour meter .........................................................................................................12

6.4 TEST PATTERNS ......................................................................................................13

7 Evaluation methods ........................................................................................................14

7.1 General .................................................................................................................14

7.2 Evaluation method table overview .........................................................................14

7.3 Visual evaluation methods.....................................................................................16

7.3.1 General .....................................................................................................16

7.3.2 Overall image quality evaluation ................................................................16

7.3.3 Greyscale resolution evaluation.................................................................17

7.3.4 LUMINANCE response evaluation.................................................................18

7.3.5 LUMINANCE uniformity evaluation................................................................19

7.3.6 Chromaticity evaluation .............................................................................19

7.3.7 Pixel faults evaluation................................................................................19

7.3.8 VEILING GLARE evaluation ...........................................................................20

7.3.9 Geometrical image evaluation....................................................................20

7.3.10 Angular viewing evaluation ........................................................................21

7.3.11 Clinical evaluation .....................................................................................22

7.4 Quantitative evaluation methods............................................................................22

7.4.1 Basic LUMINANCE evaluation.......................................................................22

7.4.2 Basic LUMINANCE evaluation without ambient light ......................................23

7.4.3 LUMINANCE response evaluation.................................................................23

7.4.4 LUMINANCE evaluation of multiple displays .................................................26

7.4.5 Chromaticity evaluation .............................................................................26

7.4.6 Chromaticity evaluation of multiple displays...............................................26

7.4.7 LUMINANCE uniformity evaluation................................................................26

7.4.8 Viewing angle evaluation ...........................................................................26

Annex A (informative) Sample test reports ...........................................................................28

Annex B (informative) LUMINANCE measurement methods ....................................................43

Annex C (informative) Description of TEST PATTERNS ............................................................46

Bibliography..........................................................................................................................55

Index of defined terms ..........................................................................................................57

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62563-1 © IEC:2009 – 3 –

Figure 1 – Overall image quality evaluation using the TG18-QC TEST PATTERN......................16

Figure 2 – Overall image quality evaluation using the TG18-OIQ TEST PATTERN.....................17

Figure 3 – Magnified view of TG18-MP TEST PATTERN showing the 8-bit and 10-bit

markers ................................................................................................................................18

Figure 4 – A close-up of the TG18-CT TEST PATTERN.............................................................19

Figure 5 – The TG18-GV TEST PATTERN is displayed (left), a close-up of the centre of

the TEST PATTERN when covered with a mask (right) ..............................................................20

Figure 6 – Geometrical evaluation using the GD pattern .......................................................21

Figure 7 – Visual evaluation of viewing angle response ........................................................22

Figure 8 – Example of the measured LUMINANCE in relation to the standard LUMINANCE

response function according to GREYSCALE STANDARD DISPLAY FUNCTION (GSDF) ...................25

Figure 9 – An example of the CONTRAST response computed from 18 grey levels as
related to the expected CONTRAST response associated with the DICOM 3.14 [2]

standard LUMINANCE response with a given tolerance limit (e.g. 15 %) [10]............................25

Figure B.1 – Method A, telescopic method ............................................................................43

Figure B.2 – Method B, near-range LUMINANCE meter in combination with an

ILLUMINANCE meter ................................................................................................................44

Figure B.3 – Method C, frontal integrated LUMINANCE meter in combination with

ILLUMINANCE meter ................................................................................................................44

Figure B.4 – Method D, back integrated LUMINANCE meter in combination with

ILLUMINANCE meter ................................................................................................................45

Figure C.1 – Example of TG-18 QC pattern for a matrix size of 1536 × 2048.........................54

Table 1 – Overview to the definitions of physical parameters ................................................10

Table 2 – TEST PATTERNS used for display testing .................................................................13

Table 3 – List of the evaluation methods that can be used for testing medical IMAGE

DISPLAY SYSTEMS ...................................................................................................................15

Table A.1 – Acceptance test sample report of a diagnostic display .......................................29

Table A.2 – Constancy test sample report of a diagnostic display .........................................33

Table A.3 – Acceptance test sample report of a monochrome reviewing display ...................35

Table A.4 – Constancy test sample report of a monochrome reviewing display .....................37

Table A.5 – Acceptance test sample report of a colour reviewing display ..............................39

Table A.6 – Constancy test sample report of a colour reviewing display................................41

Table C.1 – Description of multi-purpose TEST PATTERNS.......................................................47

Table C.2 – TG18-QC pattern: LUMINANCE levels with 8-bit and [12-bit] pixel values

and CX ratings......................................................................................................................50

Table C.3 – The blurring characteristics of the CX reference set utilized in TG18-QC

TEST PATTERNS [16] ...............................................................................................................51

Table C.4 – Evaluation criteria for the examples of the CLINICAL REFERENCE IMAGES ..............52

Table C.5 – Example description of TG-18 QC pattern for a matrix size of 1536 × 2048 ........53

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– 4 – 62563-1 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEDICAL ELECTRICAL EQUIPMENT –
MEDICAL IMAGE DISPLAY SYSTEMS –
Part 1: Evaluation methods
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

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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 62563-1 has been prepared by subcommittee 62B: Diagnostic

imaging equipment of technical committee 62: Electrical equipment in medical practice.

The text of this standard is based on the following documents:
Enquiry draft Report on voting
62B/743/CDV 62B/768/RVC

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:
---------------------- Page: 6 ----------------------
62563-1 © IEC:2009 – 5 –
– requirements and definitions: roman type;

– informative material appearing outside of tables, such as notes, examples and references: in smaller type.

Normative text of tables is also in a smaller type;
– TERMS DEFINED IN CLAUSE 3 OF THIS INTERNATIONAL STANDARD, OR AS NOTED: SMALL
CAPITALS.

A list of all parts of the IEC 62563 series, published under the general title Medical electrical

equipment – Medical image display systems, can be found on the IEC website.

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.

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.
---------------------- Page: 7 ----------------------
– 6 – 62563-1 © IEC:2009
INTRODUCTION

This International Standard provides evaluation methods for testing IMAGE DISPLAY SYSTEMS

used in MEDICAL ELECTRICAL EQUIPMENT and medical electrical systems for diagnostic imaging.

On site or after installation, two types of testing can be carried out. An acceptance test is

carried out after a new IMAGE DISPLAY SYSTEM has been installed, or major modifications have

been made to the existing IMAGE DISPLAY SYSTEM. Since an IMAGE DISPLAY SYSTEM may

degrade over time, the constancy test is carried out by the user in a periodic cycle to verify

that the performance is maintained for the intended use.

The standard describes various evaluation methods without dictating what particular tests

shall be used for acceptance and/or constancy tests.

Rather, it is the intention of this standard to be a reference for other standards and guidelines

specific to each modality or to be defined by national authorities who will refer to the

evaluation methods of this standard and mention limiting values and frequencies for

acceptance and constancy tests. Annex A shows sample reports of such a reference.

To maintain the homogeneity in the IEC standards for MEDICAL ELECTRICAL EQUIPMENT,

IEC 61223-2-5, Evaluation and routine testing in medical imaging departments – Part 2-5:

Constancy tests – Image display devices should be reviewed.
---------------------- Page: 8 ----------------------
62563-1 © IEC:2009 – 7 –
MEDICAL ELECTRICAL EQUIPMENT –
MEDICAL IMAGE DISPLAY SYSTEMS –
Part 1: Evaluation methods
1 Scope

This part of IEC 62563 describes the evaluation methods for testing medical IMAGE DISPLAY

SYSTEMS.

The scope of this International Standard is directed to practical tests that can be visually

evaluated or measured using basic test equipment. More advanced or more quantitative

measurements can be performed on these devices, but these are beyond the scope of this

document.

This standard applies to medical IMAGE DISPLAY SYSTEMS, which can display monochrome

IMAGE DISPLAY
image information in the form of greyscale values on colour and greyscale

SYSTEMS (e.g. CATHODE RAY TUBE (CRT) monitors, FLAT PANEL DISPLAYS, PROJECTION SYSTEM).

This standard applies to medical IMAGE DISPLAY SYSTEMS used for diagnostic (interpretation of

medical images toward rendering clinical diagnosis) or viewing (viewing medical images for

medical purposes other than for providing a medical interpretation) purposes and therefore

having specific requirements in terms of image quality. Head mounted IMAGE DISPLAY SYSTEMS

IMAGE DISPLAY SYSTEMS used for confirming positioning and for operation of the system

and
are not covered by this standard.

It is not in the scope of this standard to define the requirements of acceptance and constancy

tests nor the frequencies of constancy tests.
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 60788:2004, Medical electrical equipment – Glossary of defined terms
ISO 11664-1:2007, Colorimetry – Part 1: CIE standard colorimetric observers
CIE S 010/E:2004 Photometry – The CIE system of physical photometry
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions

For the purpose of this document, the terms and definitions given in IEC 60788:2004 and the

following apply.
3.1.1
accuracy
closeness of agreement between a test result and the accepted reference value
[ISO 5725-1:1994, definition 3.6]
---------------------- Page: 9 ----------------------
– 8 – 62563-1 © IEC:2009
3.1.2
brightness
LUMINANCE as perceived by the human visual system
3.1.3
cathode ray tube
CRT
picture tube

component of an IMAGE DISPLAY SYSTEM in which images defined via electrical signals are

visualized by means of an electron beam striking a phosphor
3.1.4
clinical reference image
specific medical image typical for the intended use of the IMAGE DISPLAY SYSTEM

NOTE The anatomical patterns reported in Annex C are examples of CLINICAL REFERENCE IMAGE.

3.1.5
clock artefact

artefact in form of distorted vertical bars or stripes, visible on the screens of fixed-pixel type

IMAGE DISPLAY DEVICES (e.g. LCD), when the frequency of the internal dot clock is different

from that of the incoming analogue signal
3.1.6
contrast

ratio of the difference of the LUMINANCE of two image areas, L - L ,

1 2
divided by the average of the two LUMINANCE values:
CONTRAST = 2 (L - L )/(L + L )
1 2 1 2
3.1.7
digital driving level
DDL
digital value given as input to an IMAGE DISPLAY SYSTEM producing a LUMINANCE
3.1.8
display controller

electronic component of an IMAGE DISPLAY SYSTEM that provides the analogue or digital

interface between the computer hardware and the IMAGE DISPLAY DEVICE
3.1.9
flat panel display
IMAGE DISPLAY DEVICE that is flat and thin

NOTE E.g. liquid crystal display (LCD), plasma display (PDP), field emission display (FED), surface-conduction

electron-emitter display (SED), carbon-nano-tube display (CNT), organic light-emitting display (OLED).

3.1.10
flicker
perception of unintentional fluctuations of the LUMINANCE over time
3.1.11
greyscale standard display function
GSDF

mathematically defined mapping of input, DIGITAL DRIVING LEVEL (DDL) to LUMINANCE values

based on the Barten model
---------------------- Page: 10 ----------------------
62563-1 © IEC:2009 – 9 –
[Source: DICOM PS 3.14:2007, see [2 ] ]
3.1.12
illuminance

measurement of the luminous flux incident on a surface per unit area (unit: Lux (lx),

lx = lm/m )
3.1.13
image display device
monitor

specific hardware/medium used to display images presented through an analogue or digital

interface
3.1.14
image display system

workstation consisting of an IMAGE DISPLAY DEVICE, DISPLAY CONTROLLER and computer

hardware and software, capable of displaying images
3.1.15
luminance

ratio of luminous flux penetrating (impinging on) a surface area in a specified direction to the

product of the irradiated solid angle and the projection of the surface area onto a plane

perpendicular to the viewing direction (unit: candela per square meter (cd/m ))

NOTE This definition has been derived from the term in DIN 5031-3:1982-03 [18] and is equivalent to the

definition in the International Electrotechnical Vocabulary (IEV).
3.1.16
phase artefact

artefact in form of blurred edges of displayed objects (letters, lines, etc.), visible on the

screens of fixed-pixel type IMAGE DISPLAY DEVICES (e.g. LCD), when the phase setting of the

internal dot clock is different from that of the incoming analogue signal
3.1.17
precision

closeness of agreement between independent test results obtained under stipulated

conditions
[ISO 5725-1:1994, definition 3.12]
3.1.18
projection system

large-screen IMAGE DISPLAY DEVICE which enlarges the small image generated on a plane by

central projection to a second plane
3.1.19
resolution addressability ratio
RAR

measured pixel at 50 % point of LUMINANCE at peak or nominal rating expressed as a

percentage of addressable space available
3.1.20
spatial resolution

measure of the ability of an IMAGE DISPLAY SYSTEM to distinguish spatial features of interest

within an image
—————————
Figures in square brackets refer to the Bibliography.
---------------------- Page: 11 ----------------------
– 10 – 62563-1 © IEC:2009

NOTE Systems designed with adequate SPATIAL RESOLUTION characteristics are necessary to assure that spatial

details of interest are preserved when a medical image is displayed. Portraying image data on a IMAGE DISPLAY

DEVICE with insufficient resolution will compromise the ACCURACY of the radiological interpretation.

3.1.21
test image
test pattern
image for testing or verifying the IMAGE DISPLAY SYSTEMS
3.1.22
veiling glare

enhancement of the LUMINANCE measurable on the IMAGE DISPLAY DEVICE caused by internal

scatter processes

NOTE The value of the LUMINANCE enhancement is dependent on the illuminated portion of the image displayed.

3.1.23
window setting
display of a subset of the pixel values existing in the digital image

NOTE The WINDOW SETTING is determined by the window width and level (centre) and serves for CONTRAST

enhancement.
3.2 Symbols

The symbols of physical parameters used in this standard are listed in Table 1. All

IMAGE DISPLAY DEVICE. Note that
measurements referred to in Table 1 are in the centre of the
LUMINANCE may also be measured at other locations according to the methodologies
described in this document.
Table 1 – Overview to the definitions of physical parameters
Abbreviation Mathematically derived Definition and explanation
L LUMINANCE generated by the ambient light on the surface of an
amb
IMAGE DISPLAY DEVICE when the IMAGE DISPLAY DEVICE is off.
L Minimum LUMINANCE generated by a IMAGE DISPLAY DEVICE at
min
DIGITAL DRIVING LEVEL (DDL) = 0 measured at the centre of the
screen. It includes VEILING GLARE specific to TEST PATTERN used for
measurement. It is measured with ambient light totally switched off
(in the dark).
L Maximum LUMINANCE generated by a IMAGE DISPLAY DEVICE at
max
DIGITAL DRIVING LEVEL (DDL) = max measured at the centre of the
screen. It includes VEILING GLARE specific to TEST PATTERN used for
measurement. It is measured with ambient light totally switched off
(in the dark).
L′ L + L LUMINANCE that will be perceived by the human eye at the centre of
min min amb
the screen at DIGITAL DRIVING LEVEL (DDL) = 0. It contains VEILING
GLARE and
...

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