70 Questions
What is the maximum strength of the static magnetic field created around the MR EQUIPMENT?
3 T
What must the MR EQUIPMENT display upon request or continuously?
The estimated value for the applicable SAR type
What should the operator do after an event that could affect the physical or electrical integrity of the MR equipment?
Follow the instructions for use for MR equipment
What are some possible physiological effects of exposure to the static magnetic field?
Dizziness
What must the MR equipment be designed to do to prevent cardiac stimulation in the patient and MR worker?
Automatically control the gradient waveforms
What is the strongest typically available static magnetic field?
0.02T
What is the minimum appropriate RATED hearing protection VALUE required to reduce the A-weighted RMS sound pressure level LAeq,1h to ≤ 99 dB(A)?
SLC80
What limits must the MR equipment default to if no direct determination of limits is obtained?
1.0 rb(1 + 0.36 / ts,eff
What should the instructions for use provide information about?
Areas to which access by the MR WORKER is restricted
What must the MR EQUIPMENT provide means for?
Configuring and setting adjustable limits of gradient output and/or different types of SAR
What type of magnet is used in most MR equipment?
Superconducting magnet
What should the MR WORKER do to avoid any physiological effects?
Stay as far away as possible from the static magnetic field
What should be considered when scanning sedated or unconscious patients?
The expiration date of the MR electrodes
What should the RESPONSIBLE ORGANIZATION establish to protect the MR WORKER in compliance with local regulations?
A hearing protection program
What is the unit of measurement for ts,eff?
Milliseconds
What should be done to prevent loops with RF coil cables?
Place the MR equipment against the wall
What should the RESPONSIBLE ORGANIZATION provide information on concerning the wearing of protective clothing?
Procedures to be performed after cryogen release
What happens when the QUENCH is initiated?
The static magnetic field ramps down
What must the MR EQUIPMENT have?
A default mode that is the normal operating mode
What should the instructions for use draw attention to regarding MR WORKERS?
All of the above
What type of magnet is used when the static magnetic field is normal to the long axis of the patient?
Transverse field magnet
What should the RESPONSIBLE ORGANIZATION recommend to mitigate accidents and QUENCH events?
Adequate provisions for supply of liquid cryogen
What should the instructions for use state regarding pregnant MR WORKERS?
All of the above
What should be checked during periodic preventive maintenance and inspection?
The magnet's liquid cryogen level
What noises can be heard when the QUENCH is initiated?
Hissing or whistling noises
What does the acronym PNS stand for?
Peripheral Nerve Stimulation
What must be an integral part of the image data?
The operating mode and related data
What is the maximum exposure to static magnetic fields allowed by ICNIRP guidelines for occupational exposure?
8T
What must the MR EQUIPMENT monitor and control?
Spatial encoding gradient and RF outputs
What should be avoided when scanning sedated or unconscious patients?
Contact between the patient and an RF coil cable
What is the evidence that exposure to static magnetic fields can have long-term or dose-related effects on humans?
Limited
What should the instructions for use state regarding legislation in some countries?
That these limits are lower than the limits for MR WORKER given in this document
What is the result of the stream of helium gas dissipating?
The room is filled with a dense white fog
What should be worn by people in the MR EXAMINATION ROOM to protect against the loud acoustic noise?
Adequate hearing protection
What is the lower limit for normal operating mode and the first level controlled operating mode?
0.8 rb(1 + 0.36 / ts,eff
What must the control of spatial encoding gradient and RF outputs be?
Independent of operator input
What should be done to ensure the adequacy of the venting system?
Check the magnet's liquid cryogen level
What should the instructions for use draw attention to regarding RISK factors for the MR WORKER?
All of the above
What is the risk of hearing impairment to any person present in the MR EXAMINATION ROOM during MR scanning if adequate hearing protection is not used?
Permanent hearing impairment
What is the acronym MR stand for?
Magnetic Resonance
How long does it take for the stream of helium gas to dissipate?
Minutes
What type of effects can static magnetic fields have on humans?
Macroscopic and neurological
What must the MR EQUIPMENT provide for a volume RF transmit coil?
The predicted value for the applicable SAR type
What is the purpose of the MR equipment?
To prevent cardiac stimulation in the patient and MR worker
What can third-party equipment, including patient monitoring, life-support devices, and emergency care equipment, be disturbed by?
The EMF associated with the use of MR equipment
What should be done if proper venting is not used?
The room becomes hypoxic
What should the instructions for use provide information about?
All of the above
What should be done to prevent contact between the patient and an RF coil cable?
Place the MR equipment against the wall
What is the evidence that exposure to high field magnets (7 T) may have some effects on humans?
Moderate
What should be considered when considering risk factors?
The presence of electrically-conductive objects
What should be considered before exposing humans to high field magnets (7 T)?
Both A and B
What is the upper limit for normal operating mode and the first level controlled operating mode?
1.0 rb(1 + 0.36 / ts,eff
What must the MR EQUIPMENT display continuously?
The estimated value for the applicable SAR type
What should the MR WORKER do to avoid any physiological effects?
Stay as far away as possible from the static magnetic field
What should be done by the RESPONSIBLE ORGANIZATION to ensure proper application of hearing protection on the PATIENT?
Establish dedicated training for the OPERATOR
What should the instructions for use draw attention to regarding MR WORKERS?
All of the above
What should be checked to ensure the safety of the MR equipment?
The magnet's liquid cryogen level
What is the evidence that exposure to static magnetic fields can have any effects on humans?
None
What is the risk of hearing impairment to any person present in the MR EXAMINATION ROOM if adequate hearing protection is not used?
Permanent hearing impairment
What should the instructions for use provide information about?
All of the above
What must the MR EQUIPMENT provide means for authorized operators to do?
Configure and set adjustable limits of gradient output and/or different types of SAR
What is the maximum strength of the static magnetic field created around the MR EQUIPMENT?
3 T
What does the acronym rb stand for?
Radial Bias
What happens when the QUENCH is initiated?
The static magnetic field ramps down
What type of magnet is used when the static magnetic field is parallel to the long axis of the patient?
Superconducting magnet
What should the instructions for use state regarding cumulative and/or long-term effects after exposure to EMF emitted by the MR EQUIPMENT?
That no published evidence supporting the occurrence of these effects exists
What does the acronym MR worker stand for?
Magnetic Resonance Worker
What must be included in the image data?
The operating mode and related data
What should be used when scanning patients?
MR electrodes that have not passed their expiration date
What is the sum of the specified hearing protection VALUE and the 99 dB(A) limit?
Overestimate of the actual emitted noise levels
Study Notes
- MR equipment requires periodic preventive maintenance and inspection.
- This includes checking the magnet's liquid cryogen level, and the adequacy of the venting system.
- After an event that would impact the physical or electrical integrity of the MR equipment, the operator should follow the instructions for use for MR equipment.
- Risk factors to consider include the presence of electrically-conductive objects or MEDICAL DEVICES within the sensitivity region of the RF transmit coil, contact between PATIENT and an RF coil cable, and the routing of the RF coil cable in proximity to the RF transmit coil.
- MR equipment should be placed against the wall or other non-transmitting surface to prevent loops with RF coil cables.
- MR electrodes should be used that have not passed their expiration date, and scanning of sedated or unconscious PATIENTS should be avoided.
Test your knowledge on the preventive maintenance, inspection, and safety measures for MR equipment. This quiz covers topics such as liquid cryogen level checks, risk factors to consider during operation, and proper positioning of MR equipment to prevent hazards.
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