MRSO PREP QUESTIONS & ANSWERS
Identify the precessional speed of hydrogen at a specific field strength - Answer -
Larmar equation
What does A/M equal - Answer -magnetic field strength
Created chance for induced current in our patient would be found at - Answer -
peripheral to isocenter
According to ACR manual what is the 1/2 wavelength at 7T which place a patient at risk
for resonant burns - Answer -5-7 cm
What does "rms" mean in B1+rms - Answer -do rounded value of energy producing RF
What does "+" mean in B1 + rms - Answer -energy yielding portion of our RF field
patient tissue is dielectric and will not carry a current efficiently causing heating in tissue
- Answer -ohmic heating
1.5T/3T units have a max gradient peak of - Answer -30-45 m+/m
Type of heating that is produced in tissues near RF transmitter - Answer -dipole
A way to get records on someone named in a case - Answer -discovery
Burns caused when a coil touches a patient - Answer -electrical conductivity
Allowable max strength a gradient coils ________ is measured in __________ -
Answer -max gradient peak mT/m
_________ force is responsible for noise - Answer -lorentz
What is period of time B1+rms energy delivered to our patient over - Answer -10
seconds
Mathematical equation used to convert k space into an image - Answer -fourier
equation
when the distance between a patient and wall of gantry are insufficient a burn can result
- Answer -dipole dipole effect
A wire half the wavelength of _______________ has greatest heating - Answer -
transmit frequency
,What will increase induced current in our patient - Answer -fast gradient activation and
stronger magnetic fields
type of heating where _________currents are produced in the patient - Answer -eddy
currents
When large doses of gad are delivered to a patient over a span of their life __________
occurs - Answer -retained gad or gad deposition
The higher the relaxivity of contrast media ___________ signal can be detected -
Answer -more signal
The degree that a tissue demonstrates T1 and T2 relaxation post contrast refers to
_________ - Answer -relaxivity
An object that retains a magnetic field as it is removed from a strong magnetic field -
Answer -ferromagnetic
1T=_____ G - Answer -10,000 G
Who issued the ACR manual on MRI safety in 2020 - Answer -ACR
Decrease in bandwidth can be used to _______ echo spacing - Answer -increase
If cryogen is released into MR room the patient can experience - Answer -poor visibility,
rain and snow
When flip angle is doubled heating will - Answer -quadruple
Involuntary movement of eyes side to side - Answer -nystagmus
_____ ionic gad agents demonstrate highest risk of NSF in patients with renal failure -
Answer -linear non ionic
the purpose of the ________ is to align hydrogen parallel and anti parallel to B0 -
Answer -static magnetic field
normal kidneys excrete contrast in _____ hours - Answer -24
ice packs and ___________ act as heat sinks - Answer -flowing blood
When gad breaks free from the ligand and remains in the body - Answer -NSF
Nuclei affected by __________ magnetic fields will demonstrate faster precession and
nuclei - Answer -stronger
, Larger patients produce ____ heating due to their ______ - Answer -larger, mass
Wires _______ in diameter________ in length or looped hold large risk to heating when
exposed to RF - Answer -small, long
The detection of gad in drinking water - Answer -Anthropogenic
Which would we assume would have the largest artifact 316<SS clip, cobalt clip,
titanium clip - Answer -cobalt clip
Offers the role of MR safety consultant - Answer -MRSE
In a gradient profile what describes period of time where gradients are not changing -
Answer -duty cycle
Changing gradient magnetic field RF - Answer -time varying magnetic field
Limit of static magnetic field in 1st level operating mode - Answer -8T
Vasodilation will produce __________ in contrast - Answer -tingling
Austentic is __________ stainless steel - Answer -non ferrous
Transmission of radio frequency waves into a patient can cause ______ - Answer -
heating
_______________ has established guidelines for MR safety and best practices followed
in US - Answer -ACR manual on MRI safety
Radiofrequency produced in MR unit - Answer -B1
B1+rms is measured in what - Answer -w/kg j/kg microtesla
When considering heating from RF field what is our main concern - Answer -increase
patient's core temp
Electrical current induction is at risk when scanning a pelvis with brain stimulator when
considering _______________field - Answer -time varying gradient field
time varying gradient magnetic fields are measured in - Answer -dB/d+
What will determine how well a patient will regulate their core temp - Answer -amount
of surface area on p+
F P0:B will do what - Answer -limit B1+rms plus slew rate
Identify the precessional speed of hydrogen at a specific field strength - Answer -
Larmar equation
What does A/M equal - Answer -magnetic field strength
Created chance for induced current in our patient would be found at - Answer -
peripheral to isocenter
According to ACR manual what is the 1/2 wavelength at 7T which place a patient at risk
for resonant burns - Answer -5-7 cm
What does "rms" mean in B1+rms - Answer -do rounded value of energy producing RF
What does "+" mean in B1 + rms - Answer -energy yielding portion of our RF field
patient tissue is dielectric and will not carry a current efficiently causing heating in tissue
- Answer -ohmic heating
1.5T/3T units have a max gradient peak of - Answer -30-45 m+/m
Type of heating that is produced in tissues near RF transmitter - Answer -dipole
A way to get records on someone named in a case - Answer -discovery
Burns caused when a coil touches a patient - Answer -electrical conductivity
Allowable max strength a gradient coils ________ is measured in __________ -
Answer -max gradient peak mT/m
_________ force is responsible for noise - Answer -lorentz
What is period of time B1+rms energy delivered to our patient over - Answer -10
seconds
Mathematical equation used to convert k space into an image - Answer -fourier
equation
when the distance between a patient and wall of gantry are insufficient a burn can result
- Answer -dipole dipole effect
A wire half the wavelength of _______________ has greatest heating - Answer -
transmit frequency
,What will increase induced current in our patient - Answer -fast gradient activation and
stronger magnetic fields
type of heating where _________currents are produced in the patient - Answer -eddy
currents
When large doses of gad are delivered to a patient over a span of their life __________
occurs - Answer -retained gad or gad deposition
The higher the relaxivity of contrast media ___________ signal can be detected -
Answer -more signal
The degree that a tissue demonstrates T1 and T2 relaxation post contrast refers to
_________ - Answer -relaxivity
An object that retains a magnetic field as it is removed from a strong magnetic field -
Answer -ferromagnetic
1T=_____ G - Answer -10,000 G
Who issued the ACR manual on MRI safety in 2020 - Answer -ACR
Decrease in bandwidth can be used to _______ echo spacing - Answer -increase
If cryogen is released into MR room the patient can experience - Answer -poor visibility,
rain and snow
When flip angle is doubled heating will - Answer -quadruple
Involuntary movement of eyes side to side - Answer -nystagmus
_____ ionic gad agents demonstrate highest risk of NSF in patients with renal failure -
Answer -linear non ionic
the purpose of the ________ is to align hydrogen parallel and anti parallel to B0 -
Answer -static magnetic field
normal kidneys excrete contrast in _____ hours - Answer -24
ice packs and ___________ act as heat sinks - Answer -flowing blood
When gad breaks free from the ligand and remains in the body - Answer -NSF
Nuclei affected by __________ magnetic fields will demonstrate faster precession and
nuclei - Answer -stronger
, Larger patients produce ____ heating due to their ______ - Answer -larger, mass
Wires _______ in diameter________ in length or looped hold large risk to heating when
exposed to RF - Answer -small, long
The detection of gad in drinking water - Answer -Anthropogenic
Which would we assume would have the largest artifact 316<SS clip, cobalt clip,
titanium clip - Answer -cobalt clip
Offers the role of MR safety consultant - Answer -MRSE
In a gradient profile what describes period of time where gradients are not changing -
Answer -duty cycle
Changing gradient magnetic field RF - Answer -time varying magnetic field
Limit of static magnetic field in 1st level operating mode - Answer -8T
Vasodilation will produce __________ in contrast - Answer -tingling
Austentic is __________ stainless steel - Answer -non ferrous
Transmission of radio frequency waves into a patient can cause ______ - Answer -
heating
_______________ has established guidelines for MR safety and best practices followed
in US - Answer -ACR manual on MRI safety
Radiofrequency produced in MR unit - Answer -B1
B1+rms is measured in what - Answer -w/kg j/kg microtesla
When considering heating from RF field what is our main concern - Answer -increase
patient's core temp
Electrical current induction is at risk when scanning a pelvis with brain stimulator when
considering _______________field - Answer -time varying gradient field
time varying gradient magnetic fields are measured in - Answer -dB/d+
What will determine how well a patient will regulate their core temp - Answer -amount
of surface area on p+
F P0:B will do what - Answer -limit B1+rms plus slew rate
