POLICY STATEMENT: Scientific Safety Advice to
Magnetic Resonance Imaging Units that
Undertake Human Imaging
1.
Introduction
An effective framework for the provision of safety advice in Magnetic Resonance Imaging
(MRI) is essential for the safety of patients, visitors and staff. This policy statement is issued
by the Institute of Physics and Engineering in Medicine (IPEM) to address the provision of
Magnetic Resonance (MR) scientific safety advice to MR units that undertake human
imaging in the UK. The statement was prepared by the IPEM MR Special Interest Group and
reviewed independently by a group of senior UK MR scientists.
The policy statement:

Recommends that all organisations that operate MR equipment for imaging of human
subjects should engage the services of a qualified MR Safety Expert (MRSE)

Defines typical roles and responsibilities that such a person should undertake

Defines the knowledge and competencies that such a person should possess

Proposes a national level accreditation system for MR Safety Experts
2.
Overview
MRI utilises strong magnetic fields, radiofrequency electromagnetic fields, magnetic field
gradients and cryogens. These can all be hazardous unless suitable controls and
frameworks are established.
There are many aspects of MR safety that are technical and scientific. These include but are
not limited to interpretation of national and international guidelines and legislation,
establishment of safety frameworks, site design, measurement of electromagnetic fields and
assessment of patients with implants.
To fully cover these aspects requires a person who has a thorough and detailed
understanding of MR physics and the appropriate skills, knowledge and experience to
provide safety advice. They will often need to give advice within a clinical or academic
setting and will need to have an understanding of the context in which the advice is sought
and the consequences of any advice given. They will be a member of the multidisciplinary
team that manages and maintains the safety and effectiveness of the MR unit alongside MR
unit managers, MR radiographers and radiologists. All the members of this team play an
essential and complementary role in MR safety.
In the United Kingdom, safe practice in MRI is based upon health and safety at work
legislation (UK Health and Safety at Work etc Act 1974) and a number of national and
international standards and guidelines (1-10). The UK Government Medicines and
Healthcare products Regulatory Agency (MHRA) has published Safety Guidelines for
Magnetic Resonance Imaging Equipment in Clinical Use (8). These guidelines recommend
that units should have a professional available “to adequately advise on the necessary
engineering, scientific and administrative aspects of the safe clinical use of the MR devices”
and this person is termed the MR Safety Advisor. The MHRA states that this person will
normally be a clinical scientist. The European Federation of Medical Physics (EFOMP) also
recommends (11) the provision of an MR Safety Expert to provide “high level advice on the
engineering, scientific and administrative aspects of the safe clinical use of MR devices”.
A recent survey run by the IPEM Magnetic Resonance Special Interest Group (MR-SIG)
looked at the access that MR units have to MR safety advisors (as defined by the MHRA (8))
and to Medical Physics and Engineering (MPE) Departments. The survey was sent out to
MR superintendent radiographers or equivalent across a range of hospitals and UK regions
and showed that 40 / 49 respondents used either an MPE department or a medical physicist
for MR safety advice, 4 / 49 units had an MR safety advisor who was either a radiographer
or radiologist and 5 / 49 respondents had no MR safety advisor and did not use an MPE
department for MR safety advice. Thus in total nine units (18%) did not use medical physics
expertise for scientific safety advice.
3.
Recommendations
IPEM recommends that all organisations that operate MR equipment for imaging of human
subjects should appoint an MR Safety Expert (MRSE) with a thorough knowledge of MR
physics and adequate training, knowledge and experience of MR imaging equipment, its
uses and associated requirements.
The MRSE must be able to demonstrate compliance with a defined set of scientific, technical
and clinical knowledge and competency requirements (appendix 1). They will have, or will
need to gain, an effective knowledge of the nature of the local MR service, an advanced
knowledge of MR imaging techniques and an appropriate understanding of the clinical
applications of MR. They will have an understanding of the clinical and safety consequences
of decisions made upon their advice.
The MRSE will work closely with all professions who are responsible for maintaining the
safety of the MR unit and, in particular, the individual bearing management responsibility for
safety within the MR unit (referred to in the MHRA 2007 (8) guidance as the MR Responsible
Person) who will ensure that appropriate safety policies and procedures are in place and
implemented.
Examples of specific activities falling within the role of the MRSE are to:
•
Advise on and / or develop in consultation with the MR unit management team risk-
management solutions enabling the MR unit management team to ensure that the MR unit is
safe for patients, visitors, members of the public and staff.
•
Develop safe operating procedures and policies.
•
Advise on or develop an appropriate framework for managing safety in relation to
MR, including effective review processes and reporting mechanisms within the organisation.
•
Advise on, prepare or review, and periodically revise the local safety rules in
consultation with MR unit management colleagues.
•
Advise on the local implementation of national and international MR guidelines and
legislation.
•
Audit MR units for compliance with national guidelines and good safe practice and
monitor the effectiveness of local safety procedures.
•
Provide expert scientific advice on the risks associated with individual patient
examination procedures and situations for which generic safety advice is not appropriate for
reasons of complexity or novelty. The MRSE will provide the radiologist / clinician with
guidance on the risks associated with these procedures and methods to minimise them. The
radiologist / clinician will be ultimately responsible for determining the overall benefit from the
investigation and must consider the advice provided by the MRSE when determining the
overall risk-benefit for a particular patient.
•
Advise on safety aspects of the specification, procurement and safety testing of MR
and ancillary equipment.
•
Advise on site planning and the configuration of MR facilities in order to promote
safety, working with, and recognising the experience of, the system vendor installation team.
•
Assist with the investigation of incidents relating to MR equipment.
The professional background of the MRSE will depend on the context in which they operate.
For clinical units the person must be clearly accountable and act according to recognised
standards. It is most appropriate in this instance for the MRSE to be regulated by a relevant
body i.e. they should have Health and Care Professions Council registration as a Clinical
Scientist or, as long as the necessary competencies can be demonstrated, HCPC
registration as a Radiographer or General Medical Council specialist registration. For
MRSEs who advise outside clinical units (i.e. mainly in academic units) HCPC or GMC
registration may not be necessary.
Some hospitals / Trusts will not be in a position to incorporate general scientific support to
MR imaging within their clinical service and will not have direct access to a MRSE. These
units should establish a service level agreement with an MRSE to provide appropriate MR
safety advice. Sites without an embedded MRSE should ensure that there is effective
monitoring of day to day safe working.
IPEM also recommends that an MRSE register is established. This will require a mechanism
of accreditation to ensure persons providing advice are suitably qualified and experienced.
This register will also allow MR units to quickly identify somebody who can fulfil this role.
The specific details of accreditation and registration need developing further to ensure that
the scheme will be fit for purpose, likely to be accepted by a significant majority of the MR
community and imposes a minimal, appropriate administrative load on applicants and
assessors. Details and timescales for periodic accreditation review and renewal also need
consultation. In deciding upon accreditation and registration it must be recognised that the
scientific knowledge and experience to fulfil the role of the MRSE are very different to that of
a Radiation Protection Adviser or Medical Physics Expert as defined in ionising radiation
legislation (IRR, IRMER).
References/bibliography
1. ICNIRP “Guidelines For Limiting Exposure To Time-Varying Electric, Magnetic, And
Electromagnetic Fields (Up To 300 GHz)”,Health Physics Vol.74, No4, pp494-522, 1998.
2. ICNIRP “Statement On Medical Magnetic Resonance (MR) Procedures: Protection Of
Patients”, Health Physics, Vol. 87, No 2, 2004.
3. Amendment To The ICNIRP “Statement On Medical Magnetic Resonance (MR)
Procedures: Protection Of Patients”, Health Physics, Vol. 97, No 3, 259-261, 2009.
4. ICNIRP “Guidelines On Limits Of Exposure To Static Magnetic Fields”, Health Physics,
Vol. 96, No 4, 504-514, 2009.
5. ICNIRP Statement on "Guidelines for limiting exposure to time-varying electric, magnetic
and electromagnetic fields (up to 300 GHz)”. Health Physics 97(3):257-259; 2009.
6. ICNIRP “Guidelines For Limiting Exposure To Time-Varying Electric And Magnetic Fields
(1 Hz To 100 kHz)”, Health Physics, Vol. 99, No 6, 818-836, 2010.
7. International Electrotechnical Commission (IEC). Medical Electrical Equipment –
Particular Requirements For The Safety And Essesntial Performance Of Magnetic
Resonance Equipment For Medical Diagnosis, IEC 60601-2-33:2010.
8. Medical and Healthcare products Regulatory Agency (MHRA). Safety Guidelines for
Magnetic Resonance Imaging Equipment in Clinical Use DB2007(03) London: MHRA
9. Health Protection Agency (HPA). Protection Of Patients And Volunteers Undergoing MRI
Procedures, RCE-7, 2008.
10. Health Protection Agency (HPA). Static Magnetic Fields, RCE-6, 2008.
11. The European Federation of Organisations for Medical Physics Policy Statement No 14:
The Role of the Medical Physicist in the Management of Safety within the Magnetic
Resonance Imaging Environment: EFOMP Recommendations.
Drafted by a working party on behalf of the Magnetic Resonance Special Interest Group;
comprising:
Dr Daniel Wilson, Leeds Teaching Hospitals NHS Trust
Dr John Thornton, University College London Hospitals NHS Foundation Trust
Dr Glyn Coutts, The Christie NHS Foundation Trust, Manchester
Dr Donald McRobbie, Imperial College Healthcare NHS Trust, London
Prof Stephen Keevil, Guy’s and St Thomas’ NHS Foundation Trust, London
Prof Andrew Jones, The Christie NHS Foundation Trust, Manchester
Dr Martin Graves, Cambridge University Hospitals NHS Foundation Trust
Dr John Ridgway, Leeds Teaching Hospitals NHS Trust
Appendix 1: Draft competency and knowledge and understanding list for an MRSE.
These competencies have been derived from a range of sources including but not
exclusively from the Skills for Health National Occupational Standards HCS MR1, 2, 3 and 4
(no longer available), NHS Modernising Scientific Careers Scientist Training Programme
(MSC STP) Learning Guide for Medical Physics 2012/13 (http://www.networks.nhs.uk/nhs-
networks/msc-framework-curricula/documents/STP_LG%20Medical%20Physics%20201213%20Final%20Version%20-4.pdf [accessed 26 September 2013]) and the Association of
Clinical Scientists (ACS) Medical Physics and Clinical Engineering competencies 2010
(http://www.assclinsci.org/Libraries/Application_Documents/Specific_CompetencesMedical_Physics_Clin_Engineering.sflb.ashx [accessed 26 September 2013]).
The attached competencies and knowledge and understandings will be subject to regular
review to accommodate the developing nature of clinical and research MRI.
A: An MR Safety Expert (MRSE) should be able to:Safety Framework
1
Advise on and develop an appropriate framework for managing safety in
relation to MR, which will include effective review processes and reporting
mechanisms within the organisation.
2
Specify roles, responsibilities and authority levels of relevant staff at
appropriate level of detail to facilitate implementation and management of an
MR safety framework.
3
Advise on, prepare or review, and periodically revise the local safety rules in
consultation with MR unit management colleagues.
4
Clearly specify potential risks and methods of management.
5
Specify the record-keeping requirements regarding staff training, staff and
patient exposure, volunteer exposure, contrast media and equipment
modifications.
6
Formulate contingency plans for the management and control of incidents
and emergencies.
7
Perform a comprehensive risk assessment of an MR facility and techniques.
International and national MRI guidelines and standards
8
Interpret, advise on and comply with current guidelines and standards in nonionising radiation relevant to MRI.
9
Advise on compliance with relevant legislation and its interpretation.
Electromagnetic Field (EMF) exposure
10
Advise on biological effects of static, time-varying and radio-frequency
magnetic fields.
11
Identify and use appropriate measuring equipment to establish/investigate
patient, volunteer, occupational and public exposure levels.
12
Assess and advise on occupational exposure to static, time-varying and
radio-frequency magnetic fields.
13
Advise on the implications of individual patient and / or volunteer exposures.
14
Advise on limitation or reduction of patient and / or volunteer exposure
consistent with clinical or research requirements
Implants, Foreign bodies and External Equipment.
15
Critically evaluate the safety for MR scanning of a range of inactive and active
implants and foreign bodies with particular consideration of magnetic forces,
radiofrequency heating and magnetic field gradient interactions.
16
Assess the risk and provide advice on risk mitigation for specific cases where
expert scientific input is essential for safe MRI examination e.g. patients with
complex or novel implants.
17
Provide advice on risks to patients and/or volunteers using an understanding
of the wider clinical or research situation relevant to the presenting patient or
volunteer.
18
Interpret and advise on implant manufacturer’s stated conditions for MR
conditional implants.
19
Identify and evaluate electromagnetic compatibility of external equipment and
ensure that appropriate safety systems (e.g. labelling, systems of work) exist
for the safe use of such equipment.
Siting and Procurement
20
Evaluate the mutual impact of the MR system and the surrounding
environment.
21
Establish the extent of the fringe field.
22
Critically evaluate an MR facility design.
23
Determine potential risks associated with new MR equipment accommodation
and facilities and identify effective management controls.
Miscellaneous
24
Investigate and report on adverse incidents relating to the MR equipment and
environment.
25
Advise on the hazards of and protection from acoustic noise.
B: An MR Safety Expert should have knowledge and understanding of:MR Physics
1
The physical principles of NMR and MRI.
2
The physical theory and technology underpinning clinical applications of MR.
Organisational
3
The operational dynamics of an MR facility.
4
The organisational culture of the institution.
5
Roles, responsibilities and levels of authority of personnel involved in MR
services.
6
The nature of the applications and scanning protocols used within the MR
unit.
7
Appropriate clinical or research situation relevant to the presenting patient or
volunteer.
Electromagnetic Exposure
8
The nature and biological effects of electromagnetic fields encountered in
MRI.
9
Methods of measurement and calculation of static, time-varying and radiofrequency magnetic fields
10
The relationship between pulse sequence parameters and patient / volunteer
exposure.
Guidelines and Legislation
11
Relevant national, international standards and guidelines on MR safety and
their interpretation
12
Relevant legislation and its interpretation
Site Design
13
The concept of the MR controlled areas and with the administrative controls
required to ensure safety in relation to these areas.
14
The impact of magnetic fringe fields on the environment.
15
The implications for ancillary equipment selection.
External equipment, implants and foreign bodies
16
Electromagnetic compatibility in the context of MRI and associated
equipment.
17
The principles and limitations of MR compatibility.
18
The nature and principles of bio-medical implanted devices and materials.
19
The potential and cause of RF associated heating of foreign bodies and
implants, factors that affect the degree of heating and measures to mitigate
implant heating.
20
The potential and cause of static magnetic field force and torque on foreign
bodies and implants, factors that affect the magnitude of this and measures to
mitigate the anticipated forces.
21
The potential and cause of magnetic field gradient induced electrical
stimulation on foreign bodies and implants, factors that affect the magnitude
of this and measures to mitigate it.
Hazards and risks
22
Types of risk and methods of risk management.
23
Risks associated with MR services.
24
The dangers associated with cryogens.
25
Current developments and issues in MR safety
This document has been prepared and published on behalf of the Institute of Physics and
Engineering in Medicine (IPEM). Whilst every attempt has been made to provide accurate
and useful information therein, neither the members of IPEM nor others contributing to the
document, its content, and its publication give any undertaking as to its accuracy,
comprehensiveness and usefulness. Furthermore, the same parties do not accept any
liability in respect of anyone who relies on that content.
Date first published: 8th October 2013
Next review date: 1st June 2015
Date reviewed: 8th October 2013