145 Questions
What should be used to identify ferrous objects in Zone III?
A ferromagnetic detection device
What area is Zone III?
The general area in which the MR scanner is located
What should be done before initiating a quench in a nonemergent situation?
Verify the function of emergency exhaust systems
What should design standards for passive pressure-relief mechanisms follow?
Design criteria similar to cryogen vent pathways and active exhaust
What should be done for patients with a history of orbital trauma by a potential ferromagnetic foreign body?
Obtain plain x-ray orbit films
Who is responsible for ensuring the safe execution of all MR examinations?
The MRMD
What is the minimum number of MR Personnel required when two machines are in use during scheduled hours?
Two Level 2s
What should be done to reduce the risk of lead or tissue heating during MR scanning?
Position the leads or wires as far away from the inner walls of the MR scanner as possible
What is the safety of MRI at field strengths higher than 1.5 T during pregnancy?
It has not been thoroughly assessed, but no harmful effects have been found
What is the unit of SAR?
Watts per kilogram
What is Faraday's Law?
A law stating that a changing magnetic field will induce a voltage and subsequent current in a perpendicularly oriented electrical conductor
What is the most important step before performing an MRI scan?
Evaluate the patient by a Level 2 physician
What should all MR Personnel do as part of their employment agreement?
Undergo an MR screening process
What is the responsibility of the MRMD?
To ensure appropriate evaluation and screening of patients and health care personnel
What should MR facilities arrange to do in order to ensure safety?
Educate local fire marshals
What is the main challenge of implementing MR safety policies and standard operating procedures in new MR facilities?
Personnel
What should be done for patients with an unclear history of an implanted intracranial aneurysm clip?
Obtain CT or MR images
What is the minimum number of MR Personnel required when one machine is in use during lunch or an evening shift?
One Level 1 and one Level 2
Who is responsible for the development, implementation, and maintenance of MR safety policies and procedures?
The MRSO
What should be the primary focus when dealing with a medical emergency in Zone IV?
Stabilizing the patient
Who may establish and attend to peripheral IV access lines?
IV injection-qualified MR personnel
What should be done to reduce the risk of RF exposure causing thermal injury?
Warn patients of the possibility of heat injury
What is the consensus regarding the use of gadolinium-based contrast agents (GBCAs) in pregnancy?
They should be avoided
What is the primary rationale for implementing SED limits?
To protect the patient from experiencing core temperature elevations
What type of label should be attached to a portable metallic or partially metallic object before it can be brought into Zone IV?
A triangular yellow MR Conditional label
What screening is required for conscious, nonemergency patients before they are allowed into Zone III?
Questioning by Level 2 Personnel
What should be provided for visual observation by Level 2 MR Personnel to access pathways into Zone IV?
A closed entry door
What should be included in an emergency preparedness plan?
Contact information for the MRI system vendor
What is the current construction of many RF-shielded observation windows?
Difficult to break
What is the location of the magnet poles and therefore maximal SFG?
The outer edges of the openings or entrance(s) to the magnet bore
What is the minimum number of MR Personnel required when patients or research subjects are present in Zones II through IV?
Three Level 1s
Who is responsible for the development of an appropriate investigation and recording of MR safety adverse events?
The MRSE
What should be documented before an MR examination of a patient with an intracranial aneurysm clip?
The manufacturer, model, and type of aneurysm clip
What should be done if an unanticipated ferromagnetic implant or foreign body is discovered during an MRI scan?
Immediately notify the MRMD and/or Level 2 MR Physician responsible for the patient
What is Lenz's Law?
A law asserting that the induced current will generate a secondary magnetic field that opposes the original magnetic field
What should be done with the entry door to Zone IV?
It should be closed except when it must remain open for patient care or room/MR system maintenance
What should MRI facilities inspect annually?
Cryogen vent systems
What should be done with skin staples or SMSs near the area to be irradiated?
Cover them with a cold compress or ice pack
What must be done with all devices before they are brought into Zone IV?
Labeled
What type of monitoring is often necessary during MR examinations?
Thermal injury monitoring
What should be done in the event of a system quench?
Evacuate Zone IV
What should be done for research and volunteer subjects before they are allowed into Zone III?
Questioning by Level 2 Personnel
What is the risk-benefit analysis that should accompany the decision to administer an MR GBCA to pregnant patients?
A well-documented and thoughtful risk-benefit analysis.
What is the most likely consequence of a seismic event?
Damage to the RF shield enclosure
What is the difference between SAR and SED?
SAR is the rate of energy absorption, while SED is the total dose of energy
What should be done for patients in whom there are long electrically conductive leads before permitting access to the MR scanner?
Review and clear them by an attending Level 2 MR Physician
What is the minimum number of MR Personnel required when Non-MR Personnel are in Zones III or IV?
One Level 1 and one Level 2
What should be done if a patient cannot provide a reliable history?
Plain-film radiography
What is the recommended procedure for patients with non-MR Conditional cardiac devices?
Perform an MR examination
What has been demonstrated regarding some of the MR GBCAs and the placental barrier?
They can pass through the placental barrier and enter the fetal circulation.
What type of monitoring can be accomplished using pulse oximetry?
Heart rate and rhythm
What is the minimum strength of the handheld magnet that should be used for testing portable metallic or partially metallic objects?
1000 G
What type of hazard may be posed to patients in Zone III?
Magnetic hazard
What is not advised for cardiac or respiratory arrest?
Quenching the superconductive magnet
What must be established and implemented in order to ensure infection control?
Standard operating procedures
What is the magnitude of the voltages and current generated when an electrical conductor is moved through the SFG?
Directly proportional to the rate of motion as well as the regional SFG value
What should be done to help safeguard against thermal injuries or burns?
Place pads between the patient’s skin and any transmit RF coil
Who is responsible for the safety of personnel within the MRI environment?
The MRMD
What should the cryogen safety exclusion zone be devoid of?
All of the above
What should be done to protect gantries and sensitive electronics in an emergency?
Provide backup power for the vacuum pump/cold head
What should facilities assess to ensure it meets minimum design requirements?
The current cryogen vent system
What are the guidelines for sedation protocols in MRI?
The American Academy of Pediatrics, the American Society of Anesthesiologists, and The Joint Commission (TJC).
What should be primarily considered when selecting physiological monitoring during MR examinations?
Risk of thermal injury
What is the most important thing to have in place with MRI equipment and facilities?
Emergency preparedness plans
What is the most important factor to consider when attempting to “retrofit” safe practices into an intraoperative/interventional MR environment?
Planning
What should be done to reduce the potential for lead or tissue heating during MR scanning?
Apply cold compresses or ice packs to contact areas
What is the requirement for Level 2 MR Personnel when Non-MR Personnel are in Zones III or IV?
They must be accompanied by, or under the immediate supervision of, a Level 2 MR Personnel
What is an acceptable form of documentation for a patient with an implanted intracranial aneurysm clip?
Electronic copies of operative reports
What is the maximum sound pressure that MRI can produce with hearing protection in place?
99 dB(A
What should not have free access to Zone III or IV?
Firefighters
Who is expected to provide advice on the engineering, scientific, and administrative aspects of the safe use of MR equipment?
The MRSE
What should patients do during MRI scans?
Remain motionless
What should be done with the entry door to Zone IV during times that it must remain open?
A “caution” barrier should be implemented
What should be done for children before they are allowed into Zone IV?
Questioning by Level 2 Personnel
What is the potential for thermal injury to adjacent or contiguous patient tissue increased by?
Large currents or voltages induced in the patient
What should be done in the event of a medical emergency in Zone IV?
Initiate basic life support
What is the potential risk of performing an MR examination on a patient with an intracranial aneurysm clip?
Death
What should be analyzed in both horizontal and vertical orientations to identify areas that may pose a hazard to patients?
Magnetic-field-strength spatial plots
What should be done with electrically conductive implants near the skin?
Cover them with a cold compress or ice pack
Who should make screening criteria exceptions for accompanying companions?
Qualified, responsible Level 2 MR Physician
What should be done before administering MRI contrast agents?
Only be administered by a duly licensed physician
What is the main concern for metallic implants, devices, and foreign bodies in the 7 T environment?
Resonant circuit-induced heating
What should facilities ensure the cryogen discharge point has?
A weather-head
What is the most sensitive to water of the following?
MRI equipment
What should be in place before initiating any MR sequences?
Hearing protection
What type of label should be attached to a portable object that is known to be nonmetallic and not electrically conductive?
A square green MR Safe label
Who may be external to the organization performing the scan?
The MRSE
What is the recommended method for monitoring body temperature in the neonatal and young pediatric population in the MR suite?
Temperature monitoring equipment and neonatal isolation transport units and other warming devices.
What is the total energy absorbed by the patient referred to as?
SED
What is the potential for lead or tissue heating during MR scanning?
High
What should be included in an emergency preparedness plan for restoring clinical services?
Contact information for affiliated hospital and professional organizations
What is the gradient of the static magnetic field around an MR scanner?
Decreasing with increasing distance from the physical poles of the magnet hardware
What type of label should be attached to a portable object that is known to be ferromagnetic and MR Unsafe?
A round red MR Unsafe label
What is the MR Safety Coordinator expected to provide advice on?
MR Safety Programs
What area is Zone II?
The area where patients are greeted and allowed to move freely before entering Zone III.
What is the largest group that requires sedation for MRI?
Children
What is the FDA's position on 7 T MR scanners?
Cleared for clinical use
What is the purpose of an emergency exhaust pathway for MRI systems that use superconducting magnets?
To provide a means of timely pressure relief in the event of a quench
What is the primary difference between thermal load and focal RF-related thermal injury?
Thermal load is dissipated over time, while thermal injury is not
What should be done before performing an MRI scan?
Evaluate the patient by a Level 2 physician
What should be provided to the Non-MR Personnel individual before undergoing radiographic screening?
Written informed consent
What should be the focus when dealing with a medical emergency in Zone IV?
Stabilizing the patient
What type of data is helpful for patients with postoperatively retained cardiac pacing wires?
Survey data
What should be done for higher-field systems and faster-spin-echo sequences?
Review and clear them by an attending Level 2 MR Physician
What should be provided for free access to Zone III?
Access keys or passkeys
What is the purpose of patient risk assessment before an MRI scan?
To assess potential risks associated with MRI
What should be done if someone is experiencing cardiac or respiratory arrest?
Move the patient as quickly and safely as possible
What should be done when determining whether a certain patient diagnostic question should undergo MRI?
Risk-versus-benefit assessment
What is the purpose of ultrafast MR examinations?
To diagnose conditions without the need for sedation.
What is the purpose of the SFG map or chart supplied by the MR system manufacturer?
To demonstrate the strength of the SFG at specific locations
What should be taken into consideration when electrically conductive material is required to be within the volume undergoing direct RF irradiation?
Large-caliber electrically conducting loops
What should be done for patients with an implanted intracranial aneurysm clip that is not MR Conditional?
Perform a risk-benefit assessment
What should be done only in nonemergent situations?
Initiate a quench
What should the MR Safety Coordinator keep in close contact with?
Regional and Professional Bodies
What should the individual be aware of before undergoing radiographic screening?
The risks and benefits of the procedure
What should facilities inspect after any significant seismic event or damage to the building?
Cryogen vent systems
What should be done if an implanted device is inadvertently exposed to any level of the MR system's energies?
Immediately notify the MRMD and/or Level 2 MR Physician responsible for the patient
What is the main purpose of Zone IV?
To prevent the introduction of potentially dangerous objects or equipment
What is the unit of SED commonly reported in?
Kilojoules per kilogram
What should the cryogen discharge point be positioned so that it cannot enter or occlude the pipe?
All of the above
What right should the individual be aware of before undergoing radiographic screening?
The right to refuse the screening
What is the secondary magnetic field induced by the current generated when an electrical conductor is moved through the SFG?
Oriented in the opposite direction as the motion of the conductor
What should be done after the patient is stabilized?
Evacuate the patient from Zone IV
What should be labeled as potentially hazardous in Zone IV?
Magnetic field
What should be done to ensure that non-MR personnel and materials are not brought into Zone IV?
Restrict access to Zone IV until the patient is removed from the scanner
What has been the majority of published material regarding the acoustic safety of fetal scanning?
It has found no deleterious effects on newborn hearing if exposed to MRI in utero.
What should be done for patients with a history of injury or implantation associated with a ferromagnetic foreign body or implant?
Undergo further investigation
What can RF exposure from MR scans cause?
Heat injury
What is the most likely consequence of power outages?
Loss of cryogen levels
What should be done with MR scans of prisoners/detainees?
Obtain permission from the corrections department
Who is responsible for providing safety advice regarding nonroutine MR procedures?
The MRSE
What is the effect of certain medications on the patient’s thermoregulatory responses to a heat load?
Synergistic
What should be included in an emergency preparedness plan?
Instructions on how to protect gantries and sensitive electronics
Who should have hearing protection in place when undergoing research sequences?
Both patients and volunteers
What should the MR Safety Coordinator report back to the MRMD and MRSO on?
Safety-related Root Cause Analyses
Who may administer MRI contrast agents?
A duly licensed physician
What is the increased exposure level of first-trimester pregnancies to gadolinium?
Increased screening and vigilance may be warranted
What type of environment presents substantial challenges for intraoperative/interventional MR?
Dynamic MR environment
What area is Zone IV?
The MR scanner room itself.
What should the magnet room for superconducting magnets also be provided with?
An additional form of passive pressure relief
What could potentially happen when quenching a superconductive magnet?
It could take more than a minute
What type of label should be attached to a portable object that has an MR Conditional status?
A triangular yellow MR Conditional label
What should be done with leads or wires during MR scanning?
Position the leads or wires as close to the inner walls of the MR scanner as possible
What is the risk of MRI scanning of an intracranial aneurysm clip (or other implant)?
Adverse event
What should be obtained in advance for Non-MR Personnel individuals before undergoing radiographic screening?
Written informed consent
Study Notes
- All individuals responsible for safety in Zones III or IV of the MR environment should be documented as having been successfully educated regarding MR safety issues (in a manner defined by the facility’s MRMD).
- MR Personnel are individuals who have passed the facility’s MR safety educational requirements (as defined by the facility’s MRMD) to ensure that they would not constitute a danger to themselves or others in the MR environment.
- There are 2 levels of MR Personnel, Level 1 MR Personnel and Level 2 MR Personnel. Level 1 MR Personnel are individuals who have passed the facility’s MR safety educational requirements (as defined by the facility’s MRMD) to ensure that they would not constitute a danger to themselves or others in the MR environment. Level 2 MR Personnel are those who have been more extensively trained and educated in the broader aspects of MR safety issues, including but not limited to issues related to the potential for RF-related thermal loading or burns and direct neuromuscular excitation from rapidly changing gradients.
- There will be a minimum of two MR technologists or one MR technologist and one other individual with the designation MR Personnel in the immediate Zone II through Zone IV MR environment whenever patients are in the MR environment. During this time, the two MR Personnel must be able to directly communicate within earshot of each other at all times. In all other ways, the ACR MR Safety Committee supports the Veterans Health Administration responsibilities directive 1105.05 for the Medical Facility Director of 2018: ensuring that when routinely scheduled patients or research subjects are present in Zones II through IV, there will be a minimum number of MR personnel in Zones III through IV to assure safe operation and adequate access control.
- There will be a minimum of one Level 2 MR Personnel for each machine and a minimum of one additional MR personnel, i.e. two machines during scheduled hours will require two Level 2 MR personnel and an additional Level 1 or 2 MR personnel.
- When only one machine is in use, e.g. during lunch or an evening shift, there will be a minimum of two MR personnel in Zones III through IV, and at least one of these personnel will be designated as Level 2 MR Personnel.
- Non-MR Personnel must be accompanied by, or under the immediate supervision of and in visual contact with, an individual from Level 2 MR Personnel throughout their stay in Zones III or IV, except in the changing room and/or bathroom, where verbal communication is sufficient.
- Level 1 MR Personnel are permitted unaccompanied access throughout Zones III and IV. Level 1 MR Personnel are not permitted to directly admit, or to be responsible for, Non-MR Personnel in Zones III or IV.
- No Level 2 MR Personnel shall relinquish their responsibility to supervise Non-MR Personnel in Zones III and/or IV until such supervision has been formally transferred to other Level 2 MR Personnel.
Test your knowledge of MRI personnel safety regulations with this quiz. Learn about the requirements for level 1 and level 2 MRI personnel, supervision of non-MRI personnel, and safety protocols in different zones of the MRI environment.
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