MRI Research Safety and Ethics: Points to Consider
September 14, 2005
National Institute of Mental Health
Bethesda, MD
Sponsored by:
NIMH Council Workgroup on MRI Research Practices
Summary
Background and Purpose
As with any complex and evolving technology, the use of magnetic resonance imaging (MRI) for research
raises important issues concerning the protection of human subjects or participants. In view of the
increasing involvement of MRI technology in human subjects (HS) research, particularly in non-clinical (i.
e., university rather than mainly medical research) settings, NIMH recognizes the need to consider safety
and ethical issues related to both the administration of MR (magnetic resonance) facilities and the use of
these facilities for research.
What was once a tool used primarily for medical diagnosis has become a valuable tool for clinical and
basic cognitive and affective neuroscience research. This evolution raises questions regarding how to
protect the safety of participants without unduly impeding important research. Although the protection of
human participants must remain the paramount consideration, regardless of the setting in which MRI
research occurs (e.g., university settings vs. medical centers), approaches to and use of MRI in research
vary by context or environment. NIMH recognizes the lack across various research settings of any
comprehensive guidance to assist investigators in reviewing the issues posed by MRI research concerning
the safety and protection of human participants.
To address the above-noted concerns, the National Advisory Mental Health Council (NAMHC)
Workgroup on MRI Research Practices was convened on September 14, 2005. Participants included
NIMH Council members engaged in MRI research, intramural and extramural scientists including those
involved in pediatric work, MR safety experts, including MR physiologists, MR physicists and
neuroradiologists, and an attorney with expertise in health-related research issues. The major goal of the
Workgroup was to enhance the protection of human participants by developing a set of "points to
consider" for institutions and investigators conducting or considering MRI research. The NIMH believes
that investigators, institutions and facilities can use this document as a resource for the development,
administration, evaluation, and use of MRI research facilities.
The development of this document was guided by peer-reviewed publications and empirical data to the
fullest extent possible. Where sufficient data were lacking, the Workgroup sought to acknowledge this
limitation and to identify the need for additional data. Furthermore, because technology is evolving
rapidly and new applications of MR continue to be discovered, it is expected that new questions will arise.
Thus, this list should be updated periodically if it is to be kept current.
Many of the issues discussed here have been considered previously in some form in the American College
of Radiology (ACR) White Paper on MR Safety, published in 2002 and revised in 2004 (Kanal et al.,
2002, 2004) and in other recent publications (Shellock, 2001, 2006; Shellock and Crues, 2004).
Researchers are strongly encouraged to consult these documents, and wherever relevant and appropriate,
to follow the recommendations contained therein. The ACR reports were focused primarily, however, on
the use of MR in medical settings. The present considerations are intended to encompass the broader use
of MRI in human neuroscience research, including studies conducted at facilities that exist outside of
medical settings. These research settings raise additional issues that are complementary to those addressed
by the ACR report. Consideration of these research-specific issues was a primary focus of the NIMH
Council Workgroup.
This document summarizes the "points to consider" discussed by the NAMHC Workgroup. Examples of
safe and ethical practices are discussed in relation to several issues. These examples are intended to be
illustrative and should not be interpreted as an exhaustive or exclusive list. This document was presented
to the full NIMH Council on September 15, 2006 and approved unanimously. By making the "points to
consider" document available publicly, NIMH intends to provide a resource for researchers and
institutions that use MRI in research.
Organization of Meeting and Report
The agenda was organized into six topics, which provide the organization for the points to consider that
follow:
A. MRI screening
B. Training, operating, and emergency procedures
C. Physical facilities
D. Scanning/participant health variables
E. Context- Specific Considerations: University vs. medical settings
F. Additional data needs and updating
Points to Consider
A. MRI Screening
Are there procedures in place to ensure the adequate screening of participants prior to scanning?
A-1. Is a screening form designed for maintaining MR safety in use at the facility as part of the
research?
The Workgroup agreed on the need for careful and comprehensive screening of all individuals who enter
the MRI suite, i.e., all participants and any caretakers, such as parents, who accompany children into the
MRI suite, as well as anyone who routinely enters or has access to the facility (e.g., maintenance workers,
security, as well as cleaning and emergency personnel). The use of a screening form was felt to constitute
a useful approach. The Workgroup felt that it was good practice to document all screening procedures in
writing and to make this information available to MRI facility researchers and staff.
A sample screening form is included in the American College of Radiology White Paper on MR Safety,
along with the accompanying MR Safe Practice Guidelines (Kanal et al., 2002). Another sample
screening form for patients and research subjects may be downloaded from www.mrisafety.com or www.
IMRSER.org. A Spanish version of this screening form is available from the ACR website: www.acr.org.
A-2. Are there concerns about the participant's comprehension of questions related to issues of
safety?
The Workgroup recognized the need for complete and trustworthy information from participants and/or
their caregivers and was concerned that incomplete or inaccurate responses to the items included on the
screening form would be problematic. The participant should comprehend the questions on the screening
form and sign an informed consent form. In situations where there are questions or concerns about the
participant's comprehension (due to factors such as questionable decision-making capacity, etc.), but the
participant is nevertheless considered able to provide informed consent, the Workgroup recognized the
value of having a knowledgeable companion, caretaker or family member present, with the consent of the
participant, for the consent process. If there is a language barrier, an interpreter who is not a member of
the participant's family is recommended. Also appropriate in specific circumstances is the participation of
an independent physician, consent monitor, or other responsible party to help determine that the
participant satisfies all criteria for MR safety clearance prior to entering the MRI suite. Clearly the
responsibility for ensuring that it is safe for the participant and/or accompanying family/other members to
enter areas in the MRI environment that pose risks due to the presence of the magnetic field (described
below as "zones 3 or 4", see Section C-1) rests solely with the Principal Investigator and research facility.
A-3. Once the participant completes the screening form, is the information reviewed in a screening
interview?
The Workgroup recognized the value of having the screening form for the participant and/or any caretaker
who might accompany the participant into the scanner suite reviewed by a qualified interviewer who has
the authority or access to the authority to deny entry into the MRI suite and to decline to scan. The
following credentials were considered by the Workgroup as qualifying the screening interviewer for this
role: (a) Defined training and experience in MR safety and an understanding of the potential hazards
involved in both the MR environment and the MR imaging process; (b) knowledge of medical and dental
devices and implants and of foreign metallic materials and conditions that pose hazards to the health and
safety of individuals in the MR environment; and, (c) knowledge of how to assess the MR safety aspects
of implants and medical and dental devices and foreign metallic materials or how to access appropriate
and authoritative information. (See also B-1 concerning training.)
The Workgroup also recognized the value of having the interviewer administer and review the screening
form with the participant item by item, to satisfy himself/herself that the participant has thoughtfully
considered each item and that there are no contraindications to scanning. This procedure would provide
greater protection than relying solely on the participant independently filling out a written screening form.
Similarly, having the interviewer sign and date the screening form was recognized as adding value.
The importance of the interviewer's access to appropriate resources for resolving any questions related to
the safety of questionable implants, medical or dental devices or foreign metals or objects was
acknowledged. Avenues for checking the safety of devices are numerous, and include, first, written
contact with the manufacturer of the device, peer-reviewed published information, web searches and/or
consultation with designated safety experts, and discussion with an MR physicist or MR-trained
radiologist, among others.
The Workgroup also recognized that, within the research context, MR safety information may be less
available for higher field strengths (e.g., 3 Tesla (T)) and that the safety aspects of devices may vary
depending on how they are used. Thus, ready access to an identified individual with the expertise to
evaluate safety in specific situations is invaluable.
In summary, the Workgroup recognized the value of a qualified interviewer taking responsibility for
ensuring that the screening has been completed, that the screening is documented in writing with the
interviewer's signature and date, and that any questionable devices are considered safe based on the
consultation of an appropriate expert source.
A-4. Have potential contraindications to scanning been identified?
The Workgroup agreed that if the screening yields information that raises a question concerning safety,
steps should be taken to resolve the question prior to proceeding. An example would be a metalworker
who vaguely recalls an accident in which metal filings may have entered an injured the eye. In this
situation, screening, e.g., orbital film, should be used to rule out this contraindication to scanning.
Institutional Review Board (IRB) permission to acquire screening studies involving ionizing radiation
needs to be prospectively obtained. If this type of follow-up screening is not definitive or unavailable (e.
g., due to cost), the safest action would be to exclude the participant.
If information indicates a foreign body is present, the Workgroup recognized the importance of
determining its MR safety prior to scanning.
A-5. Do the screening procedures provide for redundancy?
The Workgroup recognized that a second approach to screening would provide redundancy and therefore
might increase safety. This second approach might involve a second interview just prior to scanning to
decrease the probability of missing an item that might pose a threat to safety.
As an alternative to two full interviews, a researcher could choose to include MR contraindications as part
of the screening for recruitment to the study. This brief interview could be performed prior to a participant
coming in for testing. This pre-screening should supplement, but not replace, the full MR screening
interview. On the day of testing, a qualified interviewer at the MR center would provide a thorough in-
person screening interview.
Another alternative is the use of a second approach to ensure that the participant is free of surface objects
that may be unsafe for MRI (such as pens, coins, other metals). For example, this may consist of having a
child turn all his/her pockets inside out to ensure that they are empty or a check of all pockets and the
body using an appropriately sensitive ferromagnetic-detector wand (see Section A-6 below). As a third
alternative, participants could be required to remove all clothes and jewelry and wear a gown. It remains
the responsibility of the principal investigator and the research facility to ensure to the best of their ability
that the participant does not have any ferromagnetic or other potential contraindicated devices/items
within them as a result of prior trauma, surgery, etc.
A-6. Is a hand-held high-strength magnet available for screening purposes?
The Workgroup also recognized the value of having a high strength magnet (1000 gauss or more)
available for possible use as a supplement to screening, but recognized that its use should not replace the
screening interview. Whereas such a device might be useful for assessing the ferromagnetic status of, and
screening out, potentially dangerous objects, it would not ensure that objects are safe in the MR
environment (false negatives). Thus, the Workgroup expressed a need to recognize that the use of this
magnet was supplementary to a thorough screening process and not meant in any way to replace it.
A-7. What role do ferromagnetic detectors play in the screening process?
Ferromagnetic detectors include hand held, wall-mounted and walk-through models designed to sound an
alarm when ferrous objects are detected, but to allow ferrous free, metallic objects through. Sufficiently
sensitive ferromagnetic detectors have the potential to reduce the risk of projectile incidents, patient injury
and damage to equipment. However, such devices have not yet been systematically tested with respect to
this potential. Therefore, the Workgroup opined that, at this time, ferromagnetic detectors cannot replace a
conscientious screening and/or direct physical inspection, but constitute a potentially useful supplement to
other screening measures.
A-8. What steps are in place to screen for pregnancy?
At present, there is no known risk of MR brain scanning of a pregnant woman to the developing fetus for
scanning at 4T or less, and no known mechanism of potential risk under normal operating procedures.
Nonetheless, the possibility that risks may be discovered in the future cannot be ruled out. Therefore,
exposure of fetuses to MR scanning without any prospect of direct benefit may not be ethically justifiable.
Indeed, the general policy in many clinical Radiology Departments is not to scan anyone who may be
pregnant, absent compelling clinical need. Thus, it is appropriate to screen for pregnancy and to exclude
pregnant participants for the sake of caution.
A somewhat separate, but related, issue is the fact that there may be potential risks associated with the
exposure of fetuses to some intravenously administered MR contrast agents.
It appears that most local IRBs intend to exclude potential participants who are pregnant from research
MRI procedures. Based on Federal HS protection regulations (see below), the Workgroup expects that
pregnant females will not knowingly be scanned for research purposes unless the pregnant mother and/or
fetus are the subject of an IRB approved protocol that specifically provides for the inclusion of pregnant
women and fetuses in the research. Such research would need to utilize appropriate informed consent
procedures consistent with the requirements of the Code of Federal Regulations (CFR) Title 45 (Public
Welfare) Part 46 (Protection of Human Subjects), Subpart B (Additional Protections for Pregnant
Women, Human Fetuses and Neonates Involved in Research) (45 CFR Part 46, Subpart B), as applicable.
A variety of approaches are used across centers to screen for and/or exclude pregnant or possibly pregnant
participants. Some sites simply note, during the consent/assent process, that the individual should not
participate if there is a possibility she may be pregnant. Other sites use questions that include the date of
the last menstrual period and/or whether there is any chance the potential participant might be pregnant.
Still others test for pregnancy in all females who have begun menstruation unless they are post-
menopausal or have undergone surgical procedures after which pregnancy is not a possibility. The
approach which will be used to screen for pregnancy should be described in the protocol in order for the
IRB to assess the risks and benefits of the protocol.
Pregnancy testing has the benefit of providing new information in cases where a female may not yet
realize she has conceived. Without such testing, a female may be scanned while unknowingly pregnant.
At the same time, pregnancy testing holds implications for the disclosure of such results. For example,
having a parent first learn of a child's sexual activity and/or pregnancy during the consent/assent or
screening process may be harmful for the adolescent female and her family; sensitivity to cultural
influences is warranted here. Caution is warranted to avoid accidental disclosures of pregnancy to
individuals who might be accompanying the participant.
If disclosing a pregnancy can have potential negative consequences/risks under certain circumstances,
IRBs will want to consider this issue. Investigators should consider, in advance, how an "incidental
finding" of pregnancy will be managed, i.e., whether appropriate staff are available to provide counseling
and how such findings will be reported and participants counseled. Thus, it is important that this
information be provided to the IRB so that it may carefully balance the risks and benefits pertaining to the
specific population, research procedures, and methods used to screen for pregnancy when reviewing
protocols and consent/assent procedures.
In the case of minors, the Workgroup acknowledged that sensitivity to parent-child issues was important.
To minimize the risks of placing under-age females in a potentially conflictual situation at the time of
testing, pregnancy might be mentioned as a reason not to participate at the time of recruitment. This
allows the young woman to decline to participate without providing specific information bearing on this
issue. Considerations for screening should take into account whether to screen the minor privately or with
the parent or guardian present and whether to inform parents or guardians of the results of such
screenings. As part of the assent process, the adolescent should be informed of what will be done with the
results of the screening, including any interview data and/or pregnancy testing (consistent with state and
local statutes). Sites testing for pregnancy should consider in advance how participants and/or parents will
be informed of results, and whether there are personnel on site who are adequately trained to provide
counseling. Such considerations should be discussed with the local IRB(s) in advance.
Special consideration is warranted for vulnerable populations, whose members may be less accurate in
reporting the possibility of pregnancy, e.g., minors, or potential participants with psychosis or major
depression. Added safeguards should be considered for such participants. Leaving decisions about
whether to participate up to potentially pregnant adolescents and/or people with severe mental
impairments may be unacceptable to IRBs.
Note that the issue of when a minor's health information, including pregnancy screening results, may or
must be disclosed to parents or guardians is governed by the Department of Health and Human Service's
Health Insurance Portability and Accountability Act (HIPAA) and/or other applicable privacy and state
laws. The application of HIPAA would depend upon whether the screening is performed by a HIPAA-
covered entity (such as a healthcare provider that conducts certain transactions electronically). HIPAA
may also interact with other applicable privacy and state laws. With some exceptions, HIPAA generally
requires covered entities to treat parents and guardians of un-emancipated minors as "personal
representatives" to whom the minor's records must be disclosed upon request, if the parent or guardian has
authority under applicable law (e.g., state law) to act on behalf of the minor with respect to health care
decisions. However, where a state law permits a minor to consent to pregnancy treatment without a parent
or guardian's consent and the minor does so without parental involvement, this HIPAA requirement may
not apply. Note further that state laws may govern mandatory reporting of pregnancy to Child Protective
Services, depending on the age of the adolescent, the age of the sexual partner who fathered the child, and
the difference in their ages. HIPAA would permit HIPAA-covered entities to disclose patient health
information as required by other laws. Researchers should consult their institutional legal counsel for
guidance on the parental and other disclosure requirements, if any, that apply to a particular research
setting, and the applicable requirements for reporting should be made clear to the adolescent.
Providing the results of a pregnancy test to participants or parents implicates the federal Clinical
Laboratories Improvement Act (CLIA) and state laws regulating laboratory testing.
Researchers should consult with legal counsel to ensure that screening involving pregnancy testing is
performed in compliance with applicable law.
A-9. Are there approaches in place for screening for repeat scans?
The question of screening for repeated scanning arises most commonly in cognitive neuroscience research
involving normal volunteers, some of whom may be scanned daily or weekly for some period of time.
The Workgroup discussed whether participants should complete a full screening questionnaire and
interview for each scanning session. The Workgroup recognized the value of completing the full
screening, i.e., full standard written questionnaire and interview, with appropriate signatures for each scan.
B. Training, Operating, and Emergency Procedures
Are training, operating and emergency procedures in place to help ensure participant safety?
B-1. Are specific policies and procedures for training personnel associated with the MRI facility
developed and documented?
Given that the MRI environment presents many potential dangers to untrained or improperly screened
individuals, the Workgroup recognized the need for appropriate levels of training for all individuals who
operate the scanner and/or have routine access to the MRI suite and for a clearly specified scheme for
training and certifying individuals for each level of authorization. A range of options was mentioned for
certification, including didactic training, mastery of written materials, and terms of apprenticeship, as well
as written and/or practical tests.
The following was discussed as one example of a multi-level training and certification scheme:
Level I personnel are defined as those who are authorized to have unsupervised access to the MRI suite,
but who lack authority to screen other individuals or to bring other individuals into the scanner facility.
Certification at Level I requires training in how to screen oneself, a clear understanding of what is and is
not safe in the MRI environment, and knowledge of safety procedures for entering the MRI suite and very
basic emergency procedures, e.g., knowledge of whom to call and how to rapidly access appropriate
phone numbers. Level I may include cleaning, transportation, security, and anesthesia staff, and any
others who may have legitimate reasons to enter the MRI suite unsupervised and thus need to be
appropriately trained in safety and emergency procedures.
Level II personnel are those who, in addition to Level I certification, are also certified to operate the MR
equipment, as well as to screen others for entry into the MRI suite and oversee their presence in the suite
and during scanning. They would have more in depth knowledge of MR safety issues including the safety
of different materials for the particular environment, the safety guidelines of the applicable IRBs, and
where to get additional information if needed.
Level III personnel are faculty or senior staff who, in addition to having achieved levels I and II
certification, are also certified to train and certify Level I and Level II personnel and are authorized by the
facility director to do so. These individuals would have knowledge of the requirements needed to run a
safe MRI environment and would be responsible for keeping these requirements updated.
It was felt that researchers should adhere to an accepted national standard of care consistent with safety
provisions, such as those of the ACR. Personnel should be trained on all elements relevant to their
research practices. In the terms of the ACR guidelines, those operating the scanner should be trained to
Level II status insofar as the guidelines are relevant to their research practices. For many university
settings, this may not include use of contrast agents, but will include training in regard to radiofrequency
(RF) thermal safety issues, gradient neurostimulation, and auditory concerns.
Sites may design their own training procedures so long as these adhere to nationally established standards
of care and encompass the MR potential risks to which participants might be exposed. For example, if a
site expects to have a participant undergo MR scanning of the head, MR safety training requirements for
the operator of this study would cover biological and mechanical effects of static magnetic fields, safety
aspects related to gradient and RF magnetic fields, cryogen usage and safety issues, safety aspects of
claustrophobia and other anxiety management, etc. If no sedation, intravenous medication, or MR contrast
agents are to be administered, training regarding these areas may not be required.
The Workgroup recognized that principal investigators might have certification at any one of these levels
depending on their role in running the study. Regardless of their level of certification, all responsibility for
the safety of the MRI examination will at all times rest with the principal investigator and the designated
safety officer.
The Workgroup noted the importance of the facility having clearly documented procedures for training
and certifying personnel at all levels, for keeping certifications current, and for maintaining
comprehensive, up-to-date records regarding the certification status of all personnel associated with, or
who have access to, the facility.
B-2. Are staffing patterns adequate for dealing with emergencies?
The Workgroup discussed the need to anticipate potential emergencies and to ensure the availability of
adequate personnel coverage with which to affect a quick response. The Workgroup felt that the presence
of at least two trained staff (at least one of whom had attained Level II status), at all times that a
participant or accompanying family member/escort was within an area in which the magnetic field posed
a risk (e.g., zones 3 and/or 4 as described below), would help ensure an adequate response to an
emergency.
Furthermore, for all cases in which an MR contrast agent was being administered via any route other than
by mouth, a duly licensed physician must be on site and readily accessible to handle possible adverse
reactions to the administered MR contrast agent. Research involving participants of course necessitates
whatever additional (nonspecific to the MR environment) protections are needed to deal with any medical
issues, e.g., sedation, cardiac issues, psychiatric issues, etc.
B-3. Are there clear lines of authority for dealing with safety issues?
The Workgroup recognized the need for clear lines of authority for dealing with safety issues and felt that
a good approach for ensuring this was to designate an on-site safety officer for each scan. The designation
of a single safety officer for each scan avoids ambiguity or diffusion of responsibility during an
emergency. The Workgroup felt that the equivalent of Level II certification described above was
appropriate for such an individual.
Personnel involved in the study session should be made aware of the designated safety officer for each
scan. For example, if there is more than one potential safety officer present, e.g., more than one Level II
staff member at a scan, it is important that a single individual be recognized as in charge of safety issues
prior to entry into the facility.
B-4. Are standard procedures for dealing with emergencies developed and documented at the MRI
facility and are staff prepared to implement these procedures?
The Workgroup recognized the importance of having procedures in place for dealing with emergencies,
and maintaining staff readiness to deal with potential emergencies especially in non-medical settings. The
Workgroup felt that aspects of this preparedness included knowledge of whom to call in the case of
emergencies of various sorts, immediate access to the appropriate phone numbers, how to remove a
participant from the scanner, transfer the participant onto a stretcher if necessary, evacuate him/her from
the scanning suite, and when and how to quench the magnet.
In addition to the importance of emergency preparedness, it is equally important for researchers in non-
medical settings to make it explicitly clear to participants-as part of the informed consent procedure-that
emergency medical services may not be available onsite. This precaution is to prevent participants from
mistakenly interpreting the presence of the MR scanner as evidence that they are in a medical setting with
associated emergency medical services.
Related to this point, the Workgroup discussed the merits of additional safety training, such as
cardiopulmonary resuscitation (CPR) techniques. However, because there are no known risks of a
cardiovascular event specifically associated with exposure to the MRI environment or with being scanned
(other than the presence of a pacemaker or an implantable cardioverter defibrillator), the Workgroup did
not find any reason to require that personnel associated with a research-dedicated MRI facility be certified
as having been successfully trained in CPR. Exceptions to this would include examinations of participants
who are otherwise at risk for cardiopulmonary events.
B-5. Has the MRI site established relationships with emergency resources in the facility and
community?
The Workgroup recognized the importance of establishing relationships with emergency resources within
the host institution (e.g., university or medical center), as well as in the community. The Workgroup felt
that particularly in non-medical (e.g., university) settings, where emergency workers may not expect to
find an MRI facility, the relevant services (such as the fire and police departments) should be made aware
of the existence of the facility and its special safety concerns (e.g., personnel cannot enter with air tank).
Regular meetings with such personnel were thought to be helpful for ensuring familiarity with the facility
and its safety considerations and for reviewing its emergency procedures. Also thought to be helpful was
the practice of educating public safety and risk management groups at the institution that houses the MRI
facility with respect to the MRI facility's special considerations.
B-6. What centralized system exists at the MRI facility for reporting, managing and archiving
incidents and adverse events associated with scanning?
The group discussed the need for a system for reporting and recording incidents and adverse events
associated with scanning and its value for improving safety. Such a system would allow researchers to file
incident reports and make the archive available for consultative purposes. It was also felt important that
all breaches of safety procedures and other safety-related incidents should be reported, not just those
involving actual adverse outcomes. This would provide useful information about the frequency of "near
misses" and other occurrences that might reveal weaknesses in safety procedures and/or signal a decline
in safe practices.
Researchers in clinical facilities must also be aware of any requirements imposed by the facility's risk
management reporting process and of any legal constraints upon the disclosure of incident information to
individuals outside of the institution.
C. Physical Facilities
What protections are in place in the facility to ensure safety in those areas affected by the magnetic
field? What special restrictions, equipment and experts for evaluating the MR safety of devices does
the facility provide?
C-1. What methods are in place to control and regulate access to the MRI suite (control room and
magnet)?
Some, but not all, facilities use a standard "zoning system" such as that outlined in the ACR guidelines, to
control and regulate access to the control room and magnet for safety purposes. The ACR zoning system
is described below as one example of a system that can be used. Whatever system is adopted should
provide protections comparable to those described below.
Zone 1 includes all areas that are freely accessible to the general public, and is typically outside of the
MRI environment (i.e., that portion of the environment in which the magnetic field poses a risk).
Zone 2 is the interface between the publicly accessible, uncontrolled zone 1 and the strictly controlled
zones 3 and 4 (which pose a risk). Typically, participants are greeted in zone 2 and their movement
throughout zone 2 is under at least intermittent supervision of MR personnel. This area is typically used
for initial contact and screening.
Zone 3 is the region through which there is free, physically unrestricted access to areas that pose a risk
due to the presence of the MRI scanner itself (which is in "zone 4" - see below). Zone 3 will always
include, but may extend beyond, areas that pose a risk. For example, zone 3 may include the console
room, equipment room(s), and preparatory areas, which may or may not fall within the fringe fields (five
gauss line) of the magnet, but all of which have physically unrestricted access to areas that are affected by
the magnet's electrical and/or magnetic fields. The boundaries of the five gauss line should be clearly and
visibly marked within zone 3 (e.g., with a red line on the floor and with signs indicating the presence of
the field and associated risks), so that it is clear whenever someone is approaching an area of a five gauss
or greater exposure level.
In some cases, zone 3 may involve discontinuous regions. For example, the static fringe fields of the
magnet may extend beyond the physical confines of the scanning suite, into areas that are discontinuous
from the scanner facility (e.g., into courtyards, roofs, or other areas neighboring the building). Zone 3
encompasses these additional areas. When zone 3 involves areas that fall outside of the scanning facility,
it is imperative that these additional areas and the risks they present be marked clearly and visibly.
Access to zone 3 should be strictly physically restricted, ensuring that there is fully regulated access to all
areas that pose any risk due to the presence of the magnet or its associated electromagnetic fields. This
need to restrict access applies equally to the sorts of discontinuous areas mentioned above. It is imperative
that these additional areas and the risks they present be marked clearly and visibly and that without
exception (and in accordance with their status as zone 3 areas), they be physically restricted from
inadvertent access from any non-MR personnel.
Access to zone 3 should be controlled by Level II MR personnel (with the exception that Level I
personnel are permitted to screen themselves and enter without supervision; see B-1 above). No
unscreened non-MR personnel are allowed access to zone 3. "Non-MR personnel" are those not trained or
certified with respect to MRI facilities at any level. Access should be restricted with key locks, pass key
locking systems or other reliable, physically restricting methods that can differentiate between MR
personnel and non-MR personnel. Combination locks are discouraged, since combinations can be too
easily shared with unauthorized personnel.
Zone 4 is the physical confines of the room housing the MRI scanner itself. By definition, zone 4 always
falls within zone 3. The primary significance of zone 4 pertains to the risks due the attractive forces of the
static field of the magnet (inducing projectiles), and the effects of the time varying gradient and RF fields
when imaging is in progress. The entry to zone 4 should be clearly marked, with a sign indicating the
presence of and potential danger due to the magnet.
C-2. How are areas affected by the MR system demarcated? Do danger signs clarify for whom these
areas pose risks?
The Workgroup recognized the importance of clearly demarcating the areas affected by the magnet and
for warning persons for whom the magnetic fields pose health risks. Examples offered of appropriate
signs are those indicating "Danger" and "The magnet is always on" that are typically used to demarcate
affected areas and make clear what types of persons are at risk (e.g., those with pacemakers). Other
examples are floor markings and/or barriers clearly delimiting the five gauss line.
C-3. Is MR-safe fire extinguishing equipment available and appropriately located in the MRI suite?
The Workgroup acknowledged that storing MR-safe fire extinguishing equipment in the MRI suite (i.e.,
in either zones 3 and/or 4 as described above) ensures immediate access and therefore enhances safety.
Although the risk of a fire is small, the ready availability of such equipment would prove extremely useful
in such a rare event.
The Workgroup further felt that storing such equipment in the suite helps protect against the risk of
having unsafe equipment enter the suite.
C-4. How will the MR safety of devices for the MRI research facility be assured?
Most devices used as supplementary equipment in MR settings (e.g., surface coils, cardiac recording
devices, etc.) are Food and Drug Administration (FDA)-approved. However, in cases where this is not the
case (e.g., non-FDA-approved devices developed for research, such as devices for displaying stimuli or
recording behavioral responses from the participant), the Workgroup recognized the importance of
specifying and following clear guidelines for ensuring the safety of their use in research settings.
Consistent with such practices would be a careful review by individuals competent to evaluate the safety
of such devices and the provision of a description of these devices and procedures for evaluating their
safety to the IRB.
Toward these ends, the Workgroup recognized the value of having access to one or more consultants with
the expertise needed for evaluating the MR safety of all devices used in the facility (e.g., non-standard
coils, ancillary devices for presenting stimuli and recording responses, etc.). This technical expert or
group should be competent to decide whether IRB, FDA and/or external safety consultation are needed,
that were not provided by the manufacturer of the scanner, for devices that are to be used with it.
Among the safety issues that the Workgroup felt were important to consider were the magnetic properties
of the device, as well as the potential for creating current loops that can overheat and produce burns. The
proper operational aspects of a given device relative to the MRI environment should also be considered.
C-5. Are adequate oxygen concentrations in the MRI suite ensured?
The FDA states that: "The oxygen concentration in accessible areas should not be allowed to go below
acceptable levels." Oxygen concentration can be monitored using oxygen sensors in the MRI suite, such
as those installed by the scanner manufacturers.
D. Scanning/Participant Health Variables
What standard procedures are in place in the MRI facility for protecting the participant's health,
the safe operation of the scanner, and the reporting and archiving of incidents relevant to these
issues?
D-1. What standard procedures are documented and in place for ensuring safety?
The Workgroup recognized the value of clearly documenting all procedures for the safe operation of the
scanner and the handling of adverse events and for making this documentation readily accessible to all
personnel associated with the facility. These procedures and their documentation would be an important
focus of training for Level II personnel (see Section B-1 above).
The Workgroup felt that standard procedures should also be in place for the detection and reporting of
incidental findings and other specific health and safety-related issues as described below.
D-2. Are participants always visible to and in hearing contact of the MRI operator and allowed to
terminate the scan and exit the scanner at any time?
The Workgroup felt it important that the participant be visible to and in hearing contact of the MRI
operator at all times. The Workgroup further acknowledged that the ability to voluntarily terminate a
study at any time during scanning is in accord with the federal regulations for the protection of human
subjects (Code of Federal Regulations Basic Health and Human Services Policy for Protection of Human
Research Subjects: 45 CFR 46.116 (a) (8)).
D-3. Is hearing adequately protected?
The Workgroup acknowledged the importance of using earplugs or other hearing protection during
scanning to attenuate noise levels.
Acoustic noise levels during scanning generally fall between 65 and 95 decibels (dB), but can reach more
than 120 dB. Acoustic noise levels vary depending on the pulse sequence, field strength, and other factors.
Hearing protection may lower these exposures by about 20 dB, but this may vary according to the type of
protection being used. Risks will differ given single versus repeated exposures, scan duration and the
effectiveness of the protection.
The Workgroup recognized the importance of facilities working within standards specified by the U.S.
Occupational Safety and Health Administration (OSHA 29 CFR 1910.95), which take into account the
length and level of exposures. If noise levels exceed those specified below, attenuation must be used to
decrease exposures to within these limits. The term dBA, or A-weighted decibels, refers to the sound level
when measured on an A scale of a standard sound level meter at slow response.
Hours per daySound level dBA slow response
8 90
6 92
4 95
3 97
2 100
1 1/2 102
1 105
1/2 110
1/4 or less 115
OSHA also specifies that exposure to impulsive or impact noise should not exceed 140 dB peak sound
pressure level. In addition, apart from these guidelines, a weighted root mean square sound pressure level
greater than 99 dBA with hearing protection in place poses a significant risk (according to a FDA
document: Criteria for Significant Risk Investigations of Magnetic Resonance Diagnostic Devices, issued
on July 14, 2003).
For any research participant, any MR imaging sequence that has not received FDA approval should only
be executed with hearing protection in place unless it can be documented that the anticipated auditory
levels would be clearly below established and acceptable thresholds and guidelines.
The issue of medical conditions that might increase risk for hearing loss as a result of MR-generated
acoustic noise was discussed. The Workgroup was not aware of any data to indicate that conditions such
as tinnitus or the loss of stapedial reflexes might increase susceptibility to noise-induced hearing loss due
to MR scanning, if adequate hearing protection is used to attenuate acoustic noise below allowable limits.
D-4. Do the research scans fall within FDA guidelines for magnet strength, specific absorption rate
(SAR), gradient fields' rates of change, and acoustic noise?
In 2003, the FDA specified the following nonbinding guidelines for MRI safety (http://www.fda.gov/cdrh/
ode/guidance/793.html):
Main static magnetic field: For adults, children, and infants greater than one month of age, field strengths
greater than 8T are presently considered to pose a potential significant risk. For neonates (infants under
one month of age), field strengths greater than 4T are presently considered to pose a potential significant
risk.
Specific absorption rate (SAR): The following are considered significant risks (expressed in watts per
kilogram):
Whole body average dose over 15 or more minutes: 4 W/kg
Head average dose over 10 or more minutes: 3 W/kg
Head or torso dose per gram of tissue over 5 or more minutes: 8 W/kg
Extremities dose per gram of tissue over 15 or more minutes: 12 W/kg
Gradient fields' rates of change: Any rate of change of gradient fields (dB/dt) sufficient to produce severe
discomfort or painful nerve stimulation is considered a significant risk.
Acoustic noise: A peak acoustic noise level over 140 dB is considered significant risk, as is a weighted-
root-mean sound pressure level greater than 99 dBA with hearing protection in place. (In addition to the
FDA guidelines, OSHA guidelines specify the lengths of time at which various noise levels present risks
to hearing [see D-3]).
Because the FDA considers MRI/functional MRI research studies a nonsignificant risk, no investigational
device exemption (IDE) is required. (See Information Sheet Guidance for IRBs, Clinical Investigators,
and Sponsors; Significant Risk and Nonsignificant Risk Medical Device Studies: http://www.fda.gov/oc/
ohrt/irbs/devrisk.pdf). The regulations for studies using devices such as MR scanners do not require
physician prescriptions for clinical procedures that are done as part of clinical research. The responsibility
for safety and the protection of human participants rests with the local IRB and the informed consent
process (21 CFR Part 812.5, http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm).
The Workgroup felt that no special actions were needed for research scans that fall within the FDA
guidelines concerning magnet strength, pulse sequences (gradient fields' rates of change), SAR, and peak
sound levels (except see D-3 concerning acoustic noise). Under conditions in which research scans fall
outside of FDA guidelines, the Workgroup felt it important to make the IRB aware of this and inform
participants accordingly. In such instances, the Workgroup recognized the need for consent language that
would need to be very different from that used when working within the FDA ranges.
D-5. What special precautions are in place for infant scanning?
The Workgroup discussed the need to protect against loss of body heat (hypothermia) and for physiologic
monitoring of heart rate and oxygen saturation when scanning infants.
To protect against hypothermia, the Workgroup recognized the value of monitoring core temperature,
swathing the infant tightly, using warming packs, turning off fans, and increasing the temperature in the
scanning room, as well as limiting the scan time to one hour to help prevent heat loss. The Workgroup
also recognized that significant changes from baseline in heart rate and oxygen saturation warrant
terminating the scan.
D-6. Is there a clear protocol in place for dealing with incidental findings?
The Workgroup recognized the importance of having a clear protocol for dealing with incidental findings
prior to the start of the research. Important aspects of this protocol were felt to include a consent form that
clearly distinguishes research from clinical scans, that explicitly discusses the potential for incidental
findings and associated risks, that informs the participant as to whether or not the scans will be reviewed
by a clinician qualified to render a radiological interpretation, and that describes the path that will be
taken in the event that an incidental finding occurs. The Workgroup viewed these as consistent with the
need for having a protocol in place for dealing with incidental findings in general, including non-imaging-
related incidental findings.
The Workgroup recognized the importance of not having participants confuse a research scan with a
clinical scan. This might be addressed with consent language that states that the research scan they are
receiving is not a clinical scan (e.g., may not be of clinical quality or thoroughness) to avoid any inference
that the scan rules out a medical problem. Consent language used in a non-medical setting might make it
clear that the setting is not a medical one.
Further, despite the fact that the scan may not be of clinical caliber and/or that there may be no clinically
trained investigators involved in the research, the Workgroup felt it important that participants be
informed of the possibility that an abnormality may be detected or suspected in the process of the
research, the clinical significance of which may not be clear. In this regard, the risks associated with false
positives are important to recognize and acknowledge, including unnecessary worry, expense for medical
follow-up, and possibly unpleasant or invasive medical tests.
The Workgroup considered that a clear protocol for dealing with incidental findings should be outlined
and in place (as discussed above) including the stipulation that the participant will be fully informed
concerning the policies and procedures in place concerning potential incidental findings. It will be up to
the IRB to review and approve the protocol.
In instances where the plan does not include a clinical review, if a researcher does notice something
believed to be out of the ordinary on a scan, the Workgroup considered that the researcher could alert the
participant to it. The researcher could either share the information with a physician with the participant's
(or parent/legal guardian's) consent, or encourage the participant to seek a clinical referral.
D-7. Has a qualified individual been identified who will report any incidental findings to
participants?
As stated above, there should be a protocol for dealing with incidental findings that includes a plan for
reporting suspected findings to the participant. The protocol should identify appropriate personnel or
consultants who will report such findings to the participant.
An individual responsible for reporting incidental findings should be knowledgeable of the facility's
policies with regard to the detection and reporting of incidental findings and capable of conveying the
potential significance of the findings and possible need for clinical follow-up to the participant effectively
and with sensitivity.
The Workgroup concluded that if a physician were involved in the study, he/she would be an appropriate
informant. In non-medical settings, a principal investigator or other responsible and qualified investigator
may be an appropriate person to serve in this role.
D-8. Has the need for additional safeguards for vulnerable populations, such as children, been
considered and resolved?
Members of the Workgroup expressed some concern that vulnerable populations, such as children, might
warrant additional protections. For example, the Workgroup considered cases in which an incidental
finding of potential clinical significance is merely shared with a parent who may not fully appreciate the
need for follow-up (e.g., asymptomatic malformation that was causing sub-clinical seizures and thus
impacting the child's learning). In anticipating this type of situation, one might consider obtaining
permission to inform the child's primary care physician as part of the consent process.
Other issues, not unique to MR research, include suspected child abuse or neglect, e.g., the latter
potentially associated with a parent's failure to address a child's medical needs. During a neuroimaging
study, an MRI procedure may yield findings suggestive of abuse. In such instances, state laws mandating
the reporting of suspected abuse or neglect may become relevant.
D-9. Does the research involve repeated scanning?
The Workgroup agreed that safety concerns do not dictate any set limits on the duration or frequency of
scanning. The duration of a scanning session was felt to be limited only by the participant's ability to
remain still and tolerate the scanning conditions. The appropriateness of protocols involving long or
frequent scans will be determined by the local IRB.
The Workgroup knew of no harmful biological effects of short- or long-term exposure to static magnetic
fields. The National Council on Radiation Protection and Measurements Commentary No. 18 (2003) on
the biological effects of modulated radiofrequency fields concludes "that the scientific literature related to
modulation-dependence of biological effects of RF energy is not sufficient to draw any conclusions about
possible modulation-dependence of health hazards of RF fields nor is there any apparent biophysical basis
from which to anticipate such hazards apart from very intense RF pulses produced by some specialized
military equipment."
However, guidelines to prevent excessive heating and burns associated with magnetic resonance
procedures can be found at http://www.imrser.org/PaperPDFlist.asp?pgname=Guidelines.
D-10. Are subjects with major contraindications to scanning being studied?
The Workgroup agreed that MR scanning of participants with major contraindications to scanning is only
appropriate when there is a clinical need or the research is targeted at a special population in which
potential benefits have been appropriately weighed against the risks. Major contraindications might
include, but are not limited to, metal in the eyes, cardiac pacemakers, implanted cardioverter
defibrillators, neurostimulation systems, and cochlear implants. In such instances, specific risk/benefit
ratios would, of course, be addressed by the relevant IRB, based on review of inclusion/exclusion criteria
included in study protocols.
D-11. Are participants with "minor" contraindications to MR scanning being studied?
The Workgroup discussed the situation in which participants with "minor" contraindications to scanning
are studied. A working definition of a "minor" contraindication is one which is unlikely to pose a risk, but
which may, albeit infrequently and if not carefully monitored, result in injury.
The Workgroup felt that the participant should be informed of the potential risks involved in such "minor"
contraindications and recognized the value of appropriate precautions being instituted.
The example most thoroughly discussed was that of tattoos. Given that there is some risk of burns, the
group considered the value of carefully monitoring the participant, although it has also been noted that
burns can occur before the participant notices them or develop after the participant is removed from the
scanner. Alternatively or in addition, ice packs or cold compresses might be prospectively placed on any
tattoo in the volume about to undergo RF irradiation in the MR imaging process, although there is no
consensus on the efficacy of this measure.
D-12. What should be done when a participant presents with an implant or device for which safety
information is unclear or unavailable?
The Workgroup acknowledged that participants with implants or devices for which safety information is
unclear or unavailable should not be scanned.
Ready access to a trustworthy and up-to-date list of devices and information on their MR safety was felt
to be most useful (see www.MRIsafety.com). For participants with devices for which information is
unavailable, the group agreed that the safest thing to do is to exclude the participant from study.
D-13. Are participants being scanned at field strengths for which devices in question have been
determined to be acceptable for MR procedures?
The group recognized that implants and devices that have acceptable MR conditions established at 1.5T
may not be safe at 3T. Given that field strengths as high as 7T and 8T are in use in research settings, this
may mean excluding subjects with implants and devices due to lack of safety data at higher fields.
D-14. What procedures for documenting and reporting incidents pertaining to the safe operation of
the facility are in place?
As noted in Section B-6, the Workgroup felt that a facility should have clearly defined procedures for
documenting and reporting all incidents or near incidents that pertain to the safe operation of the facility.
Such incidents include, but are not limited to, adverse events involving the health of a participant that are
required to be reported to the IRB, institutional officials, funding agencies, FDA or others. For example,
identified failures of participant screening or incidents in which objects have been drawn into the magnet
should be documented, even when these have not resulted in an injury. This helps ensure an adequate
database of information upon which existing procedures (such as screening and training) can be evaluated
and potential revisions of policy can be based.
E. Context-Specific Considerations: Medical vs. Non-Medical Settings
E-1. Are there any context-specific considerations or modifications of safety procedures applicable
to the setting?
The Workgroup recognized that while safety considerations are paramount in any setting, the
implementation of safety procedures might differ somewhat based on the context or environment.
There are generally three contexts for MRI, but particularly for functional MRI (fMRI) scanning: the
clinical environment, the dedicated research facility in a medical setting, and the non-medical
environment (e.g., a psychology or neuroscience department at a university without a medical school).
The Workgroup recognized that the last of these presents the greatest challenge in terms of devising
appropriate procedures for ensuring safety, as fewer procedures are likely to be in place independent of
the research environment.
In considering the above categories of safety issues, the Workgroup felt that:
For MRI screening, all of the same recommendations and procedures apply to all settings.
Regarding staffing and personnel issues, in the non-medical setting, the protocol and procedures to deal
with medical emergencies will need to be in place, and any relationship with a medical partner will need
to be explicated.
While Level II personnel in the medical setting will generally include ACR-certified technologists, this
may not generally be the case in non-medical research settings. Some facilities may use a hybrid model,
such as MR technologists during regular working hours and other suitably trained and certified personnel
for evening, nights and weekend operations.
Similarly, the procedures for certification may differ by setting. In non-medical settings, senior staff and
principal investigators may do the certification.
Regarding physical facilities in non-medical settings, institutional officials and personnel not affiliated
with the MRI facility may be unaware of the existence of the MRI scanner within their institution or
facility and may not be knowledgeable concerning MRI facilities and their safety requirements. This may
place a greater burden on the MRI facilities manager for identifying and managing training needs and
organizing emergency services.
Concerning scanning/participant health variables, to the extent that participants are patients or
individuals with medical conditions, the IRB and principal investigator assume responsibility for
reviewing inclusion/exclusion criteria and ensuring the safety of participants, as in any research.
Participants with medical conditions that may precipitate an emergency during scanning (e.g., epilepsy)
require additional planning, as in any research environment. This includes a clear specification of the
procedures to be followed in the scanning environment in the event of an emergency.
F. Additional Data Needs and Updating
The following questions and issues were deemed by the Workgroup to be in need of additional data,
attention, and/or guidance.
F-1. Incidental findings:
What is the base rate of incidental findings on a sufficiently large sample size to ensure reliable estimates
and, of these, how many are clinically significant? What is the likelihood of missing a clinically
significant finding when radiologists or other physicians do not routinely review research scans?
What is the likelihood of detecting a finding that eventually is determined to be clinically insignificant
(though it may have caused anxiety and expense due to further testing)?
It is possible that relevant actuarial data exist but are not properly assembled. A retrospective study, in
which a neuroradiologist read scans from a university facility in which staff have been documenting
incidental findings detected by non-physicians and the participant informed, may yield an answer.
F-2. Pregnancy:
Does MR scanning pose a risk to the fetus? Are there data from women who were scanned when unaware
they were pregnant and the consequences, if any, that can be identified?
Data on this issue bears on the issue of risks associated with testing adolescents for pregnancy vs. risks of
scanning pregnant adolescents. Testing and interviewing adolescents creates ethical issues concerning the
possible disclosure of results to parents and counseling in the event of positive tests.
F-3. MR incident reporting:
What are the rates of incidents in which metallic objects have entered the MRI suite in medical facilities
vs. non-medical facilities?
How should these incidents impact safety recommendations?
How might a centralized system for reporting, managing and archiving incidents and adverse events
associated with scanning be developed? A centralized system would be useful for collecting data with
which to improve safety. Researchers could then systematically file incident reports and access this sort of
archive for consultative purposes.
How can existing systems for reporting adverse events contribute to a centralized archive and safety
recommendations?
Although IRBs currently have reporting requirements for adverse events, these are non-uniform. Under
the Common Rule (45 CFR Part 46, Subpart A), an IRB must require reporting of all unanticipated
problems resulting in risks to participants or others, even if there is no actual injury, as these hold
implications for safety. However, IRBs may not have procedures in place to adequately inform
investigators of this reporting requirement. A breach (i.e., metal ends up where it should not be) without
resulting injury may well not be documented.
Technical breaches (e.g., a paperclip enters the scanner, but no participant is present and therefore there is
no risk to a participant) remain distinct from those required to be reported to the IRB. Nonetheless, some
facilities may choose to have a mechanism in place for reporting these technical breaches for analytic
purposes, both because such data may prove useful in maintaining the quality of the equipment and also in
further improving safety.
Actuarial data provided on the web might balance the graphic nature of accidents currently posted there.
Attention generally focuses on projectiles, but burns are a more frequent adverse event. Data of this sort
may help to focus sites on areas in need of increased attention and precautions.
F-4. Repeated scanning:
What data exist concerning the biosafety of repeated scanning?
What data are needed to establish a lack of threshold effects, i.e., adverse health effects seen only when
some critical threshold of exposure is crossed as compared to effects seen with incremental exposures?
F-5. Use of high field magnets in pediatric neuroimaging:
Is there a need for additional data on the effects of high field magnets on pediatric participants (e.g.,
potential for heating in children at 3T or higher)?
F-6. Experimental devices:
What guidelines exist for the technical testing of non-FDA approved coils and devices, including ancillary
devices designed to present stimuli and record responses in fMRI research?
Do individual sites, e.g., non-medical sites, have the authority to test and approve coils and other devices
for use in their facilities? Are they required to adhere to commercial FDA standards?
F-7. Dental appliances:
The types of dental braces and retainers frequently worn by adolescents appear to be changing fairly
rapidly with advances in orthodontics. Participant reports of heating in some instances raise issues of
safety. In addition, the issue of which dental appliances create artifacts in brain images is also of interest.
Longitudinal pediatric research frequently runs into delays caused by dental braces and other appliances,
as researchers often assume that these devices will create significant artifacts. Yet, scanning some
children and adolescents with dental braces has yielded high quality MR brain images. Access to data for
the MR conditions of various dental devices would be helpful.
References
American Society for Testing and Materials (ASTM) International. (2005). Designation: F 2503-05.
Standard practice for marking medical devices and other items for safety in the magnetic resonance
environment. West Conshohocken, PA: ASTM International.
Kanal, E., Borgstede, J.P., Barkovich, A.J., Bell, C., Bradley, W.G., Etheridge, S., Felmlee, J.P., Froelich,
J.W., Kaminski, E.M., Keeler, E.K., Lester, J.W., Scoumis, E.A., Zaremba, L.A., & Zinninger, M.D.
(2002). American College of Radiology white paper on MR safety. American Journal of Roentgenology,
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National Council on Radiation Protection and Measurements (NCRP) (2003). Commentary No. 18:
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ncrponline.org.
Shellock F.G. (2001). Magnetic resonance procedure: health effects and safety. Boca Raton, FL: CRC
press.
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Biomedical Research Publishing Group.
Shellock, F.G.,& Crues, J.V. (2004). MR procedures: Biologic effects, safety, and patient care. Radiology,
232, 635-652.
MR Safety and Ethics Resources
Publications:
Illes, J., Kirschen, M.P., Edwards, E., Stanford, L.R., Bandettini, P., Cho, M.K., Ford, P.J., Glover, G.H.,
Kulynych, J., Macklin, R., Michael, D.B., & Wolf, S.M. (2006). Ethics. Incidental findings in brain
imaging research: What should happen when a researcher sees a potential health problem in a brain scan
from a research subject? Science, 311 (5672), 783-784.
Illes, J., Kirschen, M.P., Karetsky, K., Kelly, M., Saha, A., Desmond, J.E., Raffin, T.A., Glover, G.H., &
Atlas, S.W. (2004). Discovery and disclosure of incidental findings in neuroimaging research. Journal of
Magnetic Resonance Imaging, 20 (5), 743-747.
Kanal, E., Borgstede, J.P., Barkovich, A.J., Bell, C., Bradley, W.G., Etheridge, S., Felmlee, J.P., Froelich,
J.W., Hayden, J., Kaminski, E.M., Lester, J.W., Scoumis, E.A., Zaremba, L.A., & Zinninger, M.D.
(2004). American College of Radiology white paper on MR safety: 2004 update and revisions. American
Journal of Roentgenology, 182, 1111-1114.
Kanal, E. (2004). Clinical utility of the American College of Radiology MR safe practices guidelines.
Journal of Magnetic Resonance Imaging, 19, 2-5.
Kanal, E., Borgstede, J.P., Barkovich, A.J., Bell, C., Bradley, W.G., Etheridge, S., Felmlee, J.P., Froelich,
J.W., Kaminski, E.M., Keeler, E.K., Lester, J.W., Scoumis, E.A., Zaremba, L.A., & Zinninger, M.D.
(2003). ACR blue ribbon panel response to the ADJR commentary by Shellock and Crues on the ACR
white paper on MR safety. American Journal of Roentgenology, 180, 31-35.
Kanal, E., Borgstede, J.P., Barkovich, A.J., Bell, C., Bradley, W.G., Etheridge, S., Felmlee, J.P., Froelich,
J.W., Kaminski, E.M., Keeler, E.K., Lester, J.W., Scoumis, E.A., Zaremba, L.A., & Zinninger, M.D.
(2002). American College of Radiology white paper on MR safety. American Journal of Roentgenology,
178, 1335-1347.
Katzman, G.L., Dagher, A.P., & Patronas, N.J. (1999). Incidental findings on brain magnetic resonance
imaging from 1000 asymptomatic volunteers. Journal of the American Medical Association, 282, 36-39.
Shellock, F. G. Screening Patients for MR Procedures and Individuals for the MR Environment.
(Screening Questionnaires included). Retrieved on December 6, 2006 from www.MRIsafety.com
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635-652.
Shellock, F.G. & Crues, J.V. (2002). MR safety and the American College of Radiology white paper.
American Journal of Roentgenology, 178, 1349-1352.
Websites:
Food and Drug Administration: (www.fda.gov/cdrh/ode/guidance/793.pdf)
International Society for Magnetic Resonance in Medicine (ISMRM): (www.ismrm.org)
Institute for Magnetic Resonance Safety, Education, and Research: (www.IMRSER.org)
Information Resource for MRI Safety: (www.mrisafety.com)
Acknowledgments
The NIMH wishes to acknowledge the contributions of the Workgroup and MRI safety experts to this
report and to thank them for their efforts. Dr. Jonathan Cohen, M.D., Ph.D. (Princeton) headed the
Workgroup. Members included Susan Bookheimer, Ph.D. (UCLA), John Gabrieli, Ph.D. (MIT), P. Ellen
Grant, M.D. (Harvard), Raquel Gur, M.D. (University of Pennsylvania), Jennifer Kulynych, J.D., Ph.D.
(Johns Hopkins), Beatriz Luna, Ph.D. (University of Pittsburgh), Sean Marrett, Ph.D. (Intramural NIMH),
Maryland Pao, M.D. (Intramural NIMH), Bruce Rosen, M.D., Ph.D. (Massachusetts General), Leslie
Ungerleider, Ph.D. (Intramural NIMH), Gilbert Vezina, M.D. (Children's Hospital National Medical
Center), and Loren Zaremba, Ph.D. (FDA). MR safety experts included Emanuel Kanal, M.D. (University
of Pennsylvania) and Frank Shellock, Ph.D. (University of Southern California and the Institute for
Magnetic Resonance Safety, Education and Research). Judith Rumsey, Ph.D. led NIMH Extramural staff
coordination with assistance from David Shore M.D. Liaison with other NIH Institutes was provided by
Deborah Babcock, M.D., Ph.D and Emmeline Edwards, Ph.D. (NINDS), Lisa Freund, Ph.D. (NICHD),
and Steven Grant, Ph.D. and Laurence Stanford, Ph.D. (NIDA).
Appendix 1.
New Terminology With Regard to Magnetic Resonance Imaging (MRI) and Implants and Devices
In 1997, the Food and Drug Administration (FDA), Center for Devices and Radiological Health proposed
definitions for the terms "MR safe," "MR compatible," etc. defined below. However, the FDA did not
mandate retesting and re-labeling of implants and devices that had already received approved labeling
using older terminology. Thus, while the new terms will be useful for all present and future MR safety
testing and labeling, more general terminology has been used in the preceding report.
Reference: ASTM International, Designation: F 2503-05. Standard Practice for Marking Medical Devices
and Other Items for Safety in the Magnetic Resonance Environment. ASTM International, 100 Barr
Harbor Drive, PO Box C700, West Conshohocken, Pennsylvania, 19428, 2005.
The new terms, MR Safe, MR Conditional, and MR Unsafe are defined by the above ASTM document, as
follows.
MR Safe: an item that poses no known hazards in all MRI environments. Safe items include non-
conducting, non-magnetic items such as a plastic Petri dish. An item may be determined to be MR Safe by
providing a scientifically based rationale rather than test data.
MR Conditional: an item that has been demonstrated to pose no known hazards in a specified MRI
environment with specified conditions of use. Field conditions that define the specified MRI environment
include static magnetic field strength, spatial gradient, dB/dt (time varying magnetic fields), radio
frequency (RF) fields, and specific absorption rate (SAR). Additional conditions, including specific
configurations of the item, may be required.
http://wwwntb.nimh.nih.gov/about/mripdf.htm (25 of 28)3/12/2007 12:48:17 PM
For MR Conditional items, the item labeling will include results of testing sufficient to characterize the
behavior of the item in the MRI environment. In particular, testing for items that may be placed in the
MRI environment should address magnetically induced displacement force and torque, and RF heating.
Other possible safety issues include but are not limited to, thermal injury, induced currents/voltages,
electromagnetic compatibility, neurostimulation, acoustic noise, interaction among devices, and the safe
functioning of the item and the safe operation of the MR system. Any parameter that affects the safety of
the item should be listed and any condition that is known to produce an unsafe condition must be
described.
MR Unsafe: an item that is known to pose hazards in all MRI environments. MR Unsafe items include
magnetic items such as a pair of ferromagnetic scissors.
September 14, 2005
Bethesda, MD
Chair
Jonathan D. Cohen, M.D., Ph.D.
Eugene Higgins Professor of Psychology
Director, Center for the Study of Brain, Mind and Behavior
Director, Princeton Neuroscience Institute
Princeton University
Princeton, NJ
Participant List
Susan Bookheimer, Ph.D.
Professor, Psychiatry and Biobehavioral Sciences
UCLA School of Medicine
Los Angeles, CA
John D. E. Gabrieli, Ph.D.
Grover Hermann Professor in Health Sciences and Technology and Cognitive Neuroscience
Brain and Cognitive Sciences
Massachusetts Institute of Technology
Cambridge, MA
P. Ellen Grant, M.D.
Division Head, Pediatric Radiology
Massachusetts General Hospital for Children
Assistant Professor, Harvard Medical School
Athinoula A. Martions Center for Biomedical Imaging
Boston, MA
Raquel E. Gur, M.D., Ph.D.
The Karl and Linda Rickels Professor
Vice Chair for Research Development
Departments of Psychiatry, Neurology and Radiology
Director, Neuropsychiatry Section
University of Pennsylvania Medical Center
Philadelphia, PA
Jennifer Kulynych, J.D., Ph.D.
Legal Department
The Johns Hopkins Hospital and Health System
Baltimore, MD
Beatriz Luna, Ph.D.
Laboratory of Neurocognitive Development
Western Psychiatric Institute and Clinic
University of Pittsburgh Medical Center
Pittsburgh, PA
Sean Marrett, Ph.D.
National Institute of Mental Health
Bethesda, MD
Maryland Pao, M.D.
Deputy Clinical Director
NIMH Intramural Research Program
National Institute of Mental Health
Bethesda, MD
Bruce Rosen, M.D., Ph.D.
Director, Athinoula A. Martinos Center for Biomedical Imaging
Massachusetts General Hospital
Professor, Harvard Medical School
Visiting Associate Professor
Massachusetts Institute of Technology
Charlestown, MA
Leslie Ungerleider, Ph.D.
Chief, Lab of Brain and Cognition
National Institute of Mental Health
Bethesda, MD
Gilbert Vézina, M.D. Director, Program in Neuroradiology
Professor, Radiology and Pediatrics
The George Washington University School of Medicine and Health Sciences
Children's National Medical Center
Washington, DC
Loren A. Zaremba, Ph.D.
Radiology Devices Branch
Office of Device Evaluation
Center for Devices and Radiological Health
Food and Drug Administration
Rockville, MD
MRI Safety Consultants
Emanuel Kanal, M.D.
Director, MR Services, Division of Radiology
University of Pennsylvania
Pittsburgh, PA.
Frank Shellock, Ph.D.
University of Southern California and
Institute for Magnetic Resonance Safety, Education and Research
Los Angeles, CA.
NIMH Staff Representatives
Judith M. Rumsey, Ph.D.
Division of Pediatric Translational Research and Treatment Development
David Shore, M.D.
Associate Director for Clinical Research