MRI Safety Final Exam
What in MRI causes thermal heating? - Answer-RF field
What can induce peripheral nerve stimulation in MRI? - Answer-Transient magnetic field (time varying
magnetic field)
SAR is measured in _____ per ________. - Answer-watts, kilogram
Where does the maximum peripheral nerve stimulation occur in the MRI magnet? - Answer-Periphery of
the imaging volume
What is an appropriate frequency range for a radiofrequency pulse in MRI? - Answer-30 MHz
What do we call the intensity of RF energy deposition in tissue? - Answer-Specific Absorption Rate
What can induce magnetic phosphenes? - Answer-Time varying magnetic field
Does MRI have a long term effect? - Answer-No
Which type of shielding ensures the RF energy that is present outside zone IV does not interfere with
image production inside the scan room? - Answer-Faraday shielding
The maximum SAR value for an MR system in first-level controlled mode must not raise the patient's
core body temperature by more than 1 degree Celsius. (T/F) - Answer-TRUE
, If the MR scanner indicated that the pulse sequence exceeds the SAR limit for the given patient, what
parameters can you change as a technologist? - Answer-Reduce flip angle, reduce echo train length,
reduce the number of slices per acquisition, increase time between RF pulses
These individuals have a deep knowledge base in physics, MR equipment, and biophysics of
electromagnetism - Answer-MRSE
They ensure the safety of all patients, staff, and visitors at all times when the scanners are operating -
Answer-MRMD
Their responsibility is the day-to-day safe operation of the MRI unit - Answer-MRSO
The symbol for the RF field can be labeled as B1. (T/F) - Answer-True
If an MRI facility does not have a dedicated Zone II, what is required? - Answer-Additional safety
measures may need to be incorporated
Scanner room temperature should never pass ____ degrees Fahrenheit - Answer-70
Scanner room should be at a humidity level of ___% to ___% at all times - Answer-30, 60
Magnetic flux density is measured in - Answer-Tesla / B
Magnetic field strength is measured in - Answer-Amperes per meter / H
The fringe field is always present when there is a static magnetic field. (T/F) - Answer-True
What in MRI causes thermal heating? - Answer-RF field
What can induce peripheral nerve stimulation in MRI? - Answer-Transient magnetic field (time varying
magnetic field)
SAR is measured in _____ per ________. - Answer-watts, kilogram
Where does the maximum peripheral nerve stimulation occur in the MRI magnet? - Answer-Periphery of
the imaging volume
What is an appropriate frequency range for a radiofrequency pulse in MRI? - Answer-30 MHz
What do we call the intensity of RF energy deposition in tissue? - Answer-Specific Absorption Rate
What can induce magnetic phosphenes? - Answer-Time varying magnetic field
Does MRI have a long term effect? - Answer-No
Which type of shielding ensures the RF energy that is present outside zone IV does not interfere with
image production inside the scan room? - Answer-Faraday shielding
The maximum SAR value for an MR system in first-level controlled mode must not raise the patient's
core body temperature by more than 1 degree Celsius. (T/F) - Answer-TRUE
, If the MR scanner indicated that the pulse sequence exceeds the SAR limit for the given patient, what
parameters can you change as a technologist? - Answer-Reduce flip angle, reduce echo train length,
reduce the number of slices per acquisition, increase time between RF pulses
These individuals have a deep knowledge base in physics, MR equipment, and biophysics of
electromagnetism - Answer-MRSE
They ensure the safety of all patients, staff, and visitors at all times when the scanners are operating -
Answer-MRMD
Their responsibility is the day-to-day safe operation of the MRI unit - Answer-MRSO
The symbol for the RF field can be labeled as B1. (T/F) - Answer-True
If an MRI facility does not have a dedicated Zone II, what is required? - Answer-Additional safety
measures may need to be incorporated
Scanner room temperature should never pass ____ degrees Fahrenheit - Answer-70
Scanner room should be at a humidity level of ___% to ___% at all times - Answer-30, 60
Magnetic flux density is measured in - Answer-Tesla / B
Magnetic field strength is measured in - Answer-Amperes per meter / H
The fringe field is always present when there is a static magnetic field. (T/F) - Answer-True
