IEC 60601-2-33:2002/AMD2:2007

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

IEC 60601-2-33 A2:2007
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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

– 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• withdrawn,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.
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

– 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.
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
...