SIST EN 60601-2-33:2003/A2:2008

Medical electrical equipment - Part 2-33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis (IEC 60601-2-33:2002/A2:2007)

Corrigendum to EN issued November 2008 * Superseded by EN 60601-2-33:2010

Medizinische elektrische Geräte - Teil 2-33: Besondere Festlegungen für die Sicherheit von Magnetresonanzgeräten für die medizinische Diagnostik (IEC 60601-2-33:2002/A2:2007)

Appareils électromédicaux - Partie 2-33: Règles particulières de sécurité relatives aux appareils à résonance magnétique utilisés pour le diagnostic médical (CEI 60601-2-33:2002/A2:2007)

Medicinska električna oprema - 2-33. del: Posebne varnostne zahteve za opremo za magnetno resonanco za medicinsko diagnostiko (IEC 60601-2-33:2002/A2:2007)

General Information

• Status: Withdrawn
• Publication Date: 06-Apr-2008
• Withdrawal Date: 19-Apr-2016
• ICS: 11.040.55 - Diagnostic equipment
• Technical Committee: IEMO - Electrical equipment in medical practice
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 19-Apr-2016
• Due Date: 12-May-2016
• Completion Date: 20-Apr-2016
• Directive: 93/42/EEC - Council Directive 93/42/EEC of 14 June 1993 concerning medical devices
• Ref Project: EN 60601-2-33:2002/A2:2008 - Medical electrical equipment - Part 2-33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis

Relations

• Amends: SIST EN 60601-2-33:2003 - Medical electrical equipment - Part 2-33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis (IEC 60601-2- 33:2002)
• Effective Date: 01-May-2008
• Replaced By: SIST EN 60601-2-33:2010 - Medical electrical equipment - Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis (IEC 60601-2-33:2010)
• Effective Date: 29-Jan-2023
• Replaced By: SIST EN 60601-2-33:2010 - Medical electrical equipment - Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis (IEC 60601-2-33:2010)
• Effective Date: 07-Jun-2022
• Replaced By: SIST EN 60601-2-33:2010 - Medical electrical equipment - Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis (IEC 60601-2-33:2010)
• Effective Date: 01-Oct-2013
• Amends: SIST EN 60601-2-33:2003 - Medical electrical equipment - Part 2-33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis (IEC 60601-2- 33:2002)
• Effective Date: 29-Jan-2023
• Amends: SIST EN 60601-2-33:2003 - Medical electrical equipment - Part 2-33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis (IEC 60601-2- 33:2002)
• Effective Date: 07-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60601-2-33:2003/A2:2008
01-maj-2008
0HGLFLQVNDHOHNWULþQDRSUHPDGHO3RVHEQHYDUQRVWQH]DKWHYH]DRSUHPR
]DPDJQHWQRUHVRQDQFR]DPHGLFLQVNRGLDJQRVWLNR,(&$
Medical electrical equipment - Part 2-33: Particular requirements for the safety of
magnetic resonance equipment for medical diagnosis (IEC 60601-2-33:2002/A2:2007)
Medizinische elektrische Geräte - Teil 2-33: Besondere Festlegungen für die Sicherheit
von Magnetresonanzgeräten für die medizinische Diagnostik (IEC 60601-2-
33:2002/A2:2007)
Appareils électromédicaux - Partie 2-33: Règles particulières de sécurité relatives aux
appareils à résonance magnétique utilisés pour le diagnostic médical (CEI 60601-2-
33:2002/A2:2007)
Ta slovenski standard je istoveten z: EN 60601-2-33:2002/A2:2008
ICS:
11.040.55 'LDJQRVWLþQDRSUHPD Diagnostic equipment
SIST EN 60601-2-33:2003/A2:2008 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD
EN 60601-2-33/A2

NORME EUROPÉENNE
March 2008
EUROPÄISCHE NORM

ICS 11.040.55


English version


Medical electrical equipment -
Part 2-33: Particular requirements for the safety
of magnetic resonance equipment for medical diagnosis
(IEC 60601-2-33:2002/A2:2007)


Appareils électromédicaux -  Medizinische elektrische Geräte -
Partie 2-33: Règles particulières Teil 2-33: Besondere Festlegungen für die
de sécurité relatives aux appareils Sicherheit von Magnetresonanzgeräten
à résonance magnétique utilisés für die medizinische Diagnostik
pour le diagnostic médical (IEC 60601-2-33:2002/A2:2007)
(CEI 60601-2-33:2002/A2:2007)




This amendment A2 modifies the European Standard EN 60601-2-33:2002; it was approved by CENELEC on
2008-02-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this amendment 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 amendment exists in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CENELEC member into its own language and notified to the
Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

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

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


© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60601-2-33:2002/A2:2008 E

---------------------- Page: 2 ----------------------

EN 60601-2-33:2002/A2:2008 – 2 –
Foreword
The text of document 62B/663/FDIS, future amendment 2 to IEC 60601-2-33:2002, 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 amendment A2 to
EN 60601-2-33:2002 on 2008-02-01.
The following dates were fixed:
– latest date by which the amendment has to be
implemented at national level by publication of
an identical national standard or by endorsement (dop) 2008-11-01
– latest date by which the national standards conflicting
with the amendment have to be withdrawn (dow) 2011-02-01
__________
Endorsement notice
The text of amendment 2:2007 to the International Standard IEC 60601-2-33:2002 was approved by
CENELEC as an amendment to the European Standard without any modification.
__________

---------------------- Page: 3 ----------------------

IEC 60601-2-33
Edition 2.0 2007-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 2
AMENDEMENT 2
Medical electrical equipment –
Part 2-33: Particular requirements for the safety of magnetic resonance
equipment for medical diagnosis

Appareils électromédicaux –
Partie 2-33: Règles particulières de sécurité relatives aux appareils à résonance
magnétique utilisés pour le diagnostic médical

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
R
CODE PRIX
ICS 11.040.55 ISBN 2-8318-9358-5

---------------------- Page: 4 ----------------------

– 2 – 60601-2-33 Amend.2 © IEC:2007
FOREWORD
This amendment has been prepared by subcommittee 62B: Medical imaging equipment, of
IEC Technical Committee 62: Electrical equipment in medical practice.
The text of this amendment is based on the following documents:
FDIS Report on voting
62B/663/FDIS 62B/675/RVD

Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base 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.
_____________

INTRODUCTION to Amendment 2
This second amendment to IEC 60601-2-33 addresses technical aspects of the medical
diagnostic MR SYSTEM and the MR EQUIPMENT therein, related to the safety of PATIENTS
examined with this system, the safety of the MR WORKER involved with its operation and the
safety of the MR WORKER involved with the development, manufacturing, installation, and
servicing of the MR SYSTEM. The new aspect introduced in this second amendment addresses
the fact that in some countries electromagnetic field (EMF) exposure of workers is or will be
limited by law.

Page 11
INTRODUCTION
Replace the second paragraph by the following:
SYSTEM
This International Standard addresses technical aspects of the medical diagnostic MR
and the MR EQUIPMENT therein, related to the safety of PATIENTS examined with this system,
the safety of the MR WORKER involved with its operation and the safety of the MR WORKER
involved with the development, manufacturing, installation, and servicing of the MR SYSTEM.
Where limits of electromagnetic fields (EMF) exposure of PATIENTS and MR WORKER are
stated, these limits do not imply that such levels of exposure can be assumed to be
acceptable for workers in other professional settings and for the population at large. The limits
provide a sensible balance between risks for the PATIENTS and MR WORKERS and benefits for
the PATIENTS.

---------------------- Page: 5 ----------------------

60601-2-33 Amend.2 © IEC:2007 – 3 –
Add, after the second paragraph, the following new text:
The introduced EMF exposure limits required in this standard for an MR WORKER are equal to
those allowed for PATIENTS. All exposure levels allowed for a PATIENT and for an MR WORKER
protect them against negative instantaneous and long-term health effects.
Subjective short-term physiological and sensory effects are expected for the exposure to
static magnetic fields only, these influence the well being of the MR WORKER marginally and
only during or shortly after exposure.
For the exposure to GRADIENT OUTPUT and RF transmit fields, normally no short-term
physiological and sensory effects are expected for MR WORKERS.
In addition no experimental or theoretical basis for cumulative biological effects in humans,
resulting from exposure at the allowed levels has been generally accepted.
Add, to the list of examples of organisational aspects in the fourth paragraph, the following
new item:
− rules to minimize and to limit the exposure of MR WORKERS.

Page 13
1 Scope and object
1.2 Object
Replace the first paragraph by the following:
This particular standard establishes requirements for the safety of MR EQUIPMENT to provide
protection for the PATIENT and the MR WORKER.
NOTE This standard presumes that the MR WORKERS are properly screened medically, and properly trained and
instructed in their duties.

Page 15
2 Terminology and definitions
2.12 Miscellaneous
Add, on page 21, the following new definition:
2.12.107
MR WORKER
person that because of his/her profession has to enter the CONTROLLED ACCESS AREA or
equivalent of the MAGNETIC RESONANCE SYSTEM
NOTE Other persons like MR volunteers and PATIENT carers are not covered by this definition, however
OPERATORS and staff are included in this definition (see rationale)

Page 27
6.8.2 INSTRUCTIONS FOR USE
aa) Pre-screening prior to an MR EXAMINATION
Replace the title of 6.8.2 aa) by:
aa) Pre-screening of the PATIENT and MR WORKER

---------------------- Page: 6 ----------------------

– 4 – 60601-2-33 Amend.2 © IEC:2007
Replace the first paragraph of 6.8.2 aa) as follows:
INSTRUCTIONS FOR USE shall provide clear recommendations to the USER regarding pre-
screening of PATIENTS and MR WORKERS. This specifically applies to those PATIENTS and MR
WORKERS who could be placed at risk due to their professional activity, past medical history,
present medical state and/or the physical environment of the MR EQUIPMENT. These
instructions shall indicate the need for a pre-screening program to identify such PATIENTS and
MR WORKERS at risk, and shall provide recommendations to adequately safeguard these
PATIENTS and MR WORKERS from injury. For the MR WORKER especially the risk due to the past
professional activity, which may have caused accidental implantation of ferromagnetic
materials, shall be considered.
dd) Excessive acoustic noise
Replace the title of 6.8.2 dd) by:
dd) Exposure of the PATIENT and MR WORKER to excessive acoustic noise
Replace the existing last dashed item by the following:
– shall draw attention to the fact that in some countries legislation may exist covering the
exposure of MR WORKERS to noise.
Add a last dash to 6.8.2 dd):
– shall state that for tasks in the CONTROLLED ACCESS AREA during scanning, the MR
WORKER shall wear adequate hearing protection to reach compliance with the rules for
protection of workers to noise.
hh) Static magnetic field
Replace the title of item hh) by:
hh) Exposure of the PATIENT and MR WORKER to the static magnetic field
Replace the first bullet of 6.8.2 hh) by:
– explain the possible effects that PATIENTS and MR WORKERS may experience when the
static magnetic field is above the level of NORMAL OPERATION MODE, paying particular
attention to the effects that may be experienced if the PATIENT or MR WORKER’S head is
moved rapidly while inside or close to the MR EQUIPMENT, including dizziness, vertigo,
and a metallic taste in the mouth;
Add the following dashed items:
– explain that when the main static magnetic field is higher than 2 T and not exceeding
4 T, the MR SYSTEM is continuously operating in the FIRST LEVEL CONTROLLED
OPERATION MODE and therefore ensure that MEDICAL SUPERVISION is provided for all
PATIENTS
– explain that adequate training shall be given to MR WORKERS to minimise adverse
health effects arising from the high static magnetic field. Explain the health effects
related to the increased static magnetic fields and explain the possible changes in the
MR compatibility of the tools and accessories used by the MR WORKER, as a function of
the value of the static magnetic field.
– explain that when the main static magnetic field is higher than 4 T, the MR system is
continuously operating in the SECOND LEVEL CONTROLLED OPERATION MODE and
therefore ensure that MEDICAL SUPERVISION is provided for all PATIENTS. Explain that in
this situation MR WORKERS shall not be allowed to access the MR EQUIPMENT without
local approval as required.

---------------------- Page: 7 ----------------------

60601-2-33 Amend.2 © IEC:2007 – 5 –
ii) Time varying magnetic fields
Replace the title of item ii) by the following:
ii) Exposure of the PATIENT to time varying magnetic fields
Replace the first paragraph by the following:
For MR EQUIPMENT that is capable of operation at levels of GRADIENT OUTPUT above the
NORMAL OPERATING MODE, the INSTRUCTIONS FOR USE shall draw attention to risk factors, which
may increase the potential for peripheral nerve stimulation for the PATIENT and they shall
describe ways for the USER to mitigate these risk factors. The INSTRUCTIONS FOR USE shall:
jj) Radio frequency magnetic fields
Replace title of the item jj) by:
jj) Exposure of the PATIENT to radio frequency magnetic fields
Replace the first paragraph by the following:
The INSTRUCTIONS FOR USE shall draw attention to risk factors, which may increase the
potential for local excessive RF heating of the PATIENT and they shall describe ways for the
USER to mitigate these risk factors. These factors include:
kk) Occupational exposure
Replace the existing text of this item by the following new text:
The INSTRUCTIONS FOR USE shall draw attention to the fact that MR WORKERS can be exposed
to the electromagnetic fields (EMF) emitted by the MR EQUIPMENT. They shall provide
sufficient information relating to the risks from these exposures to enable safe working
procedures for the MR WORKER. The relevant requirements of 6.8.2 ii) and jj) for the PATIENT
shall also apply for the MR WORKER. This information shall also include
– specification of areas to which access by the MR WORKER is restricted, if any;
– the actual levels of the exposure in all areas accessible to the MR WORKER, expressed in
proper units for the static magnetic field (see 6.8.2 hh) and 51.104), the GRADIENT OUTPUT
(see 6.8.2.ii) and 51.102) and the RF transmit field (see 6.8.2 jj) and 51.103) generated by
the MR EQUIPMENT;
– instructions that the MR WORKER shall be informed and trained sufficiently so that they can
perform all their tasks safely in a way that minimizes their exposure to EMF emitted by the
MR EQUIPMENT;
– a statement that there is a possibility that mild peripheral nerve stimulation (PNS) may be
induced in the PATIENT and MR WORKER when exposed to the gradients in the FIRST LEVEL
CONTROLLED OPERATION MODE;.
The risk factors associated with the expected exposure levels for the MR WORKER shall be
explained. A description of ways for the MR WORKER to mitigate these risk factors shall be
given.
Known factors to draw attention to are the following:
– The possible physiological effect of exposure to RF radiation is heating. Exposure to RF
radiation can be minimised by keeping sufficient distance away from the transmit RF coil
or by reducing time of exposure during scanning;
– The possible physiological effect of exposure to the GRADIENT OUTPUT is peripheral nerve
stimulation for the person exposed. Exposure to GRADIENT OUTPUT can be minimised by
keeping sufficient distance away from the gradient coils during scanning.
– The possible physiological effects of exposure to the static magnetic field are dizziness,
vertigo, and a metallic taste in the mouth of the person exposed. Exposure to the static
magnetic field can be minimised by staying away from the magnet (not just during

---------------------- Page: 8 ----------------------

– 6 – 60601-2-33 Amend.2 © IEC:2007
scanning but all the time) and by avoiding rapid movements of the head while in the static
magnetic field.
The INSTRUCTIONS FOR USE may state that, it is generally accepted that no published evidence
supporting the occurrence of cumulative and/or long-term effects after exposure to EMF
emitted by the MR EQUIPMENT exists.
The INSTRUCTIONS FOR USE shall state that extra precaution is advisable for pregnant MR
WORKERS, although there is no currently available epidemiological evidence for any negative
health effects. Local regulations may apply.
The INSTRUCTIONS FOR USE shall state that the limits for MR WORKERS may not be applicable
when an MR WORKER is pregnant. It may be required in some countries that the ‘member of
the public’ limit be applied to the foetus.
The INSTRUCTIONS FOR USE shall state that in some countries legislation may exist covering
occupational limits for exposure to EMF, that are lower than the limits for MR WORKER given in
this standard.

Page 39
6.8.3 Technical description
bb) compatibility technical specification sheet
Add to the dashed item Magnet the following additional bullet:
• For MR equipment that is capable of operation in the FIRST LEVEL CONTROLLED OPERATION
MODE or the SECOND LEVEL CONTROLLED OPERATION MODE for the static magnetic field, a plot
representing the 0,5 T, 1 T, 1,5 T, 2 T, 3 T and the 4 T iso-magnetic contours at positions
WORKER shall be included if the static magnetic field
accessible to and relevant for the MR
in the iso-centre exceeds any of these values.
Replace two existing dashed items as follows:
– Gradient system: type, amplitude, rise time, slew rate, and spatial distribution of the
maximum magnitude values of the vector sum of all three GRADIENT OUTPUTS at the
positions accessible to and relevant for the MR WORKER during scanning.
– RF system: types of RF transmit coil, amplifier peak r.m.s. power, applied maximum
transmit RF magnetic field and bandwidth, spatial distribution of the maximum transmit RF
magnetic field at the positions accessible to and relevant for the MR WORKER during
scanning.

Page 51
51.101 Operating modes
51.101.1 All operating modes
Replace item: c) by:
c) The MR EQUIPMENT shall provide information upon request about the relevant SAR and
relevant GRADIENT OUTPUT.
Page 53
51.101.3 FIRST LEVEL CONTROLLED OPERATING MODE
Replace item a) by:
a) Before the start of each scan, an indication of the operating mode defined by the value of
the GRADIENT OUTPUT which will actually be applied during the scan and the value of the
SAR which will actually be applied during the scan, and a prediction of these values (upon

---------------------- Page: 9 ----------------------

60601-2-33 Amend.2 © IEC:2007 – 7 –
request) shall be displayed at the CONTROL PANEL. The value for the GRADIENT OUTPUT shall
be expressed as the percentage of the upper level of the FIRST LEVEL CONTROLLED
OPERATION MODE (L12) for the scan applied.

51.101.4 SECOND LEVEL CONTROLLED OPERATING MODE
Replace item b) by:
b) Before the start of each scan, an indication of the operating mode defined by the value of
the GRADIENT OUTPUT which will actually be applied during the scan and the value of the
SAR which will actually be applied during the scan, and a prediction of these values (upon
request) shall be displayed at the CONTROL PANEL. The value for the GRADIENT OUTPUT shall
be expressed as the percentage of the upper level of the FIRST LEVEL CONTROLLED
OPERATION MODE (L12) for the scan applied.
51.102 Protection against excessive low frequency field variations produced by the
gradient system.
51.102.1 Objectives for limitation of GRADIENT OUTPUT
Replace, on page 55, the first two sentences of the existing text by the following
The MR EQUIPMENT shall be designed to automatically control the GRADIENT OUTPUT so that
cardiac stimulation in the PATIENT and in the MR WORKER at any operating mode is prevented.
The MR EQUIPMENT shall be designed to automatically control the GRADIENT OUTPUT so that the
occurrence of intolerable peripheral nerve stimulation (PNS) in the PATIENT and in the MR
WORKER in any operating mode is minimised.
51.102.2 Limits for GRADIENT OUTPUT
Replace the existing first sentence by:
In this subclause, limits for the PATIENT and the MR WORKER are expressed either as the
electric field E induced in the PATIENT or the MR WORKER by the changing magnetic field of the
gradients, or by dB/dt, the time rate of change of that field.
Add the following note at the end of the subclause:
NOTE MR WORKER exposure limits are the same as for the PATIENTS. Compliance with the GRADIENT
OUTPUT limits for PATIENTS therefore automatically implies compliance for the MR WORKERS.

Page 61
51.103 Protection against excessive radio frequency energy
51.103.1 Limits for temperature
Add to the existing first paragraph the following new text:
WORKER caused by the MR EQUIPMENT are
Allowed values for the temperature rise of the MR
equal to the values for the PATIENT as defined in Table 104 for the NORMAL OPERATING MODE
and the FIRST LEVEL CONTROLLED OPERATING MODE.
Add the following note to Table 105:
NOTE MR WORKER exposure limits are the same as for the PATIENTS. Compliance with the SAR limits for
PATIENTS therefore in practice implies compliance for the MR WORKERS.

---------------------- Page: 10 ----------------------

– 8 – 60601-2-33 Amend.2 © IEC:2007
Page 67
51.105 Methods to demonstrate compliance with the requirements
51.105.2 Determination of maximum GRADIENT OUTPUT
Add the following new title at the beginning of the existing text:
51.105.2.1 General requirement for the determination of the maximum GRADIENT
OUTPUT
Add the following new title just before the start of the italic text:
51.105.2.2 Determination of the maximum GRADIENT OUTPUT for the PATIENT
Add, on page 73, a new subclause 51.105.2.3 before 51.105.3:
51.105.2.3 Determination of the GRADIENT OUTPUT stray field as required for reporting
in 6.8.3 bb.
To be able to estimate the exposure for MR WORKERS, for each GRADIENT UNIT the spatial
maximum of the GRADIENT OUTPUT shall be determined in an extended COMPLIANCE VOLUME,
see Figures 107a and 107b. The specific point pattern shall represent worst-case locations
where the MR WORKER has access to and can be maximally exposed by the GRADIENT UNIT.
NOTE For transverse field magnet types the cylinder axis (i.e. patient axis) is perpendicular to the magnet axis.
The term patient bore is to be replaced by magnet gap between pole shoes; the term magnet length is to be
replaced by pole shoe diameter.
- The specific point pattern shall be located on a virtual cylinder surrounding the PATIENT
axis with a diameter equal to the minimum accessible PATIENT bore.
- The cylinder starts at the magnet isocentre and exceeds the PATIENT bore opening (half
the magnet length) by at least 0,5 m.
- In the cylinder axis direction the points shall have a separation of not more than 0,1 m.
- For each cylinder axis position at least 16 points shall be equidistantly spaced on the
cylinder surface (i.e. on a circle). The points shall include those located half way between
the x and y gradient axes (i.e. n x 45°, n = 1,3,5,7).
- The magnetic field vector for each GRADIENT OUTPUT shall be calculated using the law of
Biot-Savart or measured for each point on the cylinder.
- For each point the three FIELD vectors shall be summed and then the field magnitude
shall be determined.
- This maximum magnitude values shall be plotted along the cylinder axis position. The
axial position of the PATIENT bore opening shall be marked.
NOTE The pattern is also considered to be relevant for estimating possible PNS for the MR WORKER and
illustrates the relative field distribution outside the space accessible for the PATIENT.
Report of results:
• distance of points along cylinder axis;
• number of points azimuthally;
• graph of maximum magnitude values along the cylinder axis.

---------------------- Page: 11 ----------------------

60601-2-33 Amend.2 © IEC:2007 – 9 –

Add the following Figure 107:
e
n
a
d
c
b
f

i
z

i
IEC  2102/07


Figure 107a – CYLINDRICAL MAGNET

e

n
a
b d
c
z
i
f

i
IEC  2103/07

Figure 107b – TRANSVERSE FIELD MAGNET
a magnet
b magnet isocentre
c patient axis and axis of a virtual cylinder
d diameter of virtual cylinder representing the minimum accessible patient bore;
e points on the cylinder surface where the magnitude of all three magnetic field vectors shall
n
be determined. The maximum magnetic field magnitude found on the cylinder surface at
distance z from the isocentre in any of the points e represents the worst case field on the
i n
surface f .
i
Figure 107 – Determination of the spatial maximum of the gradient output

---------------------- Page: 12 ----------------------

– 10 – 60601-2-33 Amend.2 © IEC:2007
Add, on page 89, new subclause 51.105.3.3:
51.105.3.3 Determination of the B stray field as required for reporting in 6.8.3 bb)
1
The maximum RF transmit magnetic field of the RF transmit coil shall be measured or
WORKER.
calculated and reported at the positions accessible to and relevant for the MR
The B (z) field shall be measured or calculated at points along a straight line along the patient
1
axis beginning at the magnet isocentre.
NOTE For cylindrical magnets the patient axis is equivalent to the magnet axis; for TRANSVERSE FIELD MAGNET
types the cylinder axis (i.e. patient axis) is perpendicular to the magnet axis. It is sufficient to measure / calculate
the B field along the patient axis only because the B field is assumed to be sufficiently homogenous in each
1 1
transversal plane of the RF transmit coil.
- The distance between each successive point shall not exceed 0,1 m.
- The magnitude of the B field shall be measured or calculated for each point.
1
- When measured, the measurement can be performed by using a suitable pick up coil and
a network analyzer or by using an RF signal generator and a spectrum analyzer. For
magnets with circular polarized RF transmit field it is sufficient to determine the radial
component only.
2 2
(z) and B (0) shall be calculated for each point.
- The ratio of B
1 1
- The calculated value for a single point at a distance z from the magnet isocentre shall
apply to all locations on a base area of a virtual cone to represent worst-case condition
on this base area, see Figures 108a and 108b. The base area of the cone is the area
perpendicular to the straight line at distance z from the isocentre. The cone is defined by
the opening angle given by the projection from the magnet isocentre to the magnet
aperture. The height of the cone is given by the distance z. For TRANSVERSE FIELD MAGNET
types the area is defined by the superposition of base areas by rotating the cone around
the magnet isocentre.
NOTE See rationale for detailed explanation.
Report of results:
2
- coordinates of the points where B (z) is measured or calculated
1
2
(z) in the measured points relative to the magnitude
- magnitude of the magnetic field B
1
2
B (0) in the isocentre
1

---------------------- Page: 13 ----------------------

60601-2-33 Amend.2 © IEC:2007 – 11 –
Add the following new Figure 108:
e
i
a
c
b
f
i
z
i
IEC  2104/07

Figure 108 a) – CYLINDRICAL MAGNET
e
i
a
c
b

f
i
IEC  2105/07

Figure 108 b) – TRANSVERSE FIELD MAGNET
a magnet
b magnet isocentre
c patient axis
z distance of point e from isocentre.
i i
2 2
B (z ) shall be determined by measurement or calculation. The ratio B (z ) and B (0) shall be
1 i 1 i 1
calculated for each point e . The calculated value in point e shall apply for the corresponding
i i
grey area f . The value in point e always represents a worst case for any location within the
i i
area f .
i
Figure 108 – Determination of the B stray field
1

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– 12 – 60601-2-33 Amend.2 © IEC:2007
Page 95
Annex AA – Examples of warning signs and prohibitive signs

Add the following new text at the end of the annex:
Extra examples for the marking introduced for medical devices and other items for safety in
1)
the MR environment are introduced in the ASTM standard F2503-05 . This relates
specifically to markings for MR Safe, MR Conditional and MR Unsafe devices.

Page 97
Annex BB – Guidance and rationale for particular subclauses
Add the following new texts to the guidance and rationale for particular subclauses:
Concerning Introduction:
The most important new aspect introduced in this second amendment is the fact that the
employer of the MR WORKER is now encouraged to define rules and formulate requirements
for MR WORKERS, because in some countries the EMF, produced by the MR SYSTEM, may
result in exposure of workers, which is or will be limited by law.
Concerning 2.12.107 MR WORKER
The concept of MR WORKERS is related to the level of exposure of this group of workers to the
EMFs emitted by the MR system. This level may be higher than what is allowed by legal
regulations in some countries for workers in general, creating for the MR WORKER the need of
special EMF exposure limits as defined in this standard. The EMF exposure limits stated in
this document permit the unrestricted presence of the MR WORKER in CONTROLLED ACCESS
AREA even during scanning. The level of these limits and the resulting risks to the MR WORKER
are discussed elsewhere in this annex.
The term MR WORKER includes all people working near the MR EQUIPMENT in the CONTROLLED
ACCESS AREA or equivalent either in the medical arena where the MR SYSTEM is installed and
being operated and serviced or at the manufacturer where the MR SYSTEM is being developed
and manufactured. As such the MR WORKER includes but is not limited to the personnel
SYSTEM, the OPERATOR and the medical staff, or the MR WORKER can be
maintaining the MR
the technical personnel at the MR manufacturer, development and manufacturing engineers,
installation and service personnel. Both groups of M
...