EX 2 Flashcards
Who is responsible for maintaining the quench vent outside the site in zone 3?
Manufacturer engineer
Site engineer
MRI technologists
MRI Physicist
Site engineer
Which provides us a more accurate understanding of RF exposure to our patient?
SED
Tesla
B1+rms
SAR
B1+rms
We would expect the highest heating in a linear implanted device exposed to an RF frequency under what condition?
A line parallel to the RF field
Objects less than 2 cm in size
Spherical objects
Aligned perpendicular to the RF field
Aligned perpendicular to the RF field
You have reached your SAR limit and your system will not allow you to continue scanning. What can you do to reduce your SAR?
Increase slice gap
Increase flipping angle
Increase frequency encoding
Add more slices
Increase frequency encoding
Which of the following will prevent a proximity burn?
Placing a pad between a patient’s legs
Placing a pad between a patient’s calves
Placing a pad between the side of the MRI bore and the patient
All of the choices
Placing a pad between the side of the MRI bore and the patient
A titanium wrench will demonstrate the strongest translational force at which of the following?
7 T / m
No noticeable attractive forces will be seen
4 T / m
300 G / cm
No noticeable attractive forces will be seen
Slew rate offers risks associated with which of the following?
Static magnetic field
Time-varying RF
Time-varying Gradient
Time-varying Gradient
dB/dx refers to which of the following?
Time varying magnetic field
Patient Heating
Magnetic spatial gradient
Isogauss
Magnetic spatial gradient
Which of the following is true of implants exposed to a magnetic spatial gradient? Select all that apply.
The magnetic spatial gradient is used to describe threats associated with ferrous implants
The magnetic spatial gradient describes the risk of heating in the implant
An implant can exceed its MR conditional limits upon positioning the patient, but cannot remain in a location exceeding that limit during acquisition
The magnetic spatial gradient describes the change in the magnetic field over a distance
The magnetic spatial gradient is used to describe threats associated with ferrous implants
The magnetic spatial gradient describes the change in the magnetic field over a distance
The NRR helps us understand what?
The amount of sound reduction associated with hearing protection
The amount of heating produced in our patient
The safe level of magnetic exposure a patient can have
The amount of shielding the static magnetic field produces
The amount of sound reduction associated with hearing protection
OSHA sets a safe noise level for occupational workers to what?
140dBA
99dBA
70dBA
85dBA
85dBA
Which of the following produce the noises heard during an MRI?
Static magnetic field
Time-varying RF field
Time-varying gradient field
Time-varying gradient field
A cobalt screwdriver is brought into the MRI suite. Which of the following would demonstrate the strongest translational force?
6 T / m
70 g / cm
No noticeable attractive forces will be seen
0.1 T / m
6 T / m
Which of the following hold all the risk of burns that our patient may experience?
Time-varying gradient field
Time-varying RF field
Static magnetic field
Time-varying RF field
Which pulse sequence would we expect to produce the loudest noise?
All of the choices
A DWI
A FLAIR
The conventional spin echo
A DWI
A patient is given earplugs and they are not placed correctly. Which of the following could cause harm to our patient? Select all that apply.
A perfusion scan at 105 decibels A-weighting
A conventional spin echo at 84 decibels A-weighting
A fast spin echo at 103 decibels A-weighting
A diffusion-weighted image at 110 decibels A-weighting
A perfusion scan at 105 decibels A-weighting
A fast spin echo at 103 decibels A-weighting
A diffusion-weighted image at 110 decibels A-weighting
On an ECG waveform, which of the following will be elevated when the magnetohydrodynamic artifact the seen?
R wave
P wave
T wave
Q wave
T wave
An obese patient has tissue pressed against the side of the bore. What burn is the patient at risk of?
Induced loop burn
Proximity burn
Resonant burn
Proximity burn
You have reached your SAR limit and your system will not let you continue scanning. What can you do to reduce your SAR?
Decrease TR
Use parallel Imaging
Increase echo train length
Increase phase encoding
Use parallel Imaging
What is the center frequency for a 1.5T is approximately?
64 MHz
128 MHz
300 G/cm
224 MHz
64 MHz
Which of the following implants would be the largest threat in terms of only the static magnetic field?
Saline breast implant
None of the choices
Permanent retainer
Cardiac stent
None of the choices
Which of the following burns do not always occur at or near isocenter?
Resonance burns
Conductive loop burns
Proximity burns
Conductive loop burns
Pressure build-up during an improper quench can cause a door opening ______ to be sealed and not open.
Outward
Inward
Inward
The missile effect describes which of the following?
Translational forces
Peripheral nerve stimulation
RF Heating
Rotational forces
Translational forces
Which of the following are suggestions offered by the ACR Manual on MRI Safety?
Have a lit sign that says magnet on
Full stop and final check
Line of sight rule
Gives instructions and how to evaluate implant deflection for MR labeling
Have a lit sign that says magnet on
Full stop and final check
Line of sight rule
_____ describes gadolinium getting into the water supply.
Gadolinium retention
None of the choices
NSF
Anthropogenic
Anthropogenic
We are scanning a patient foot with a transmit-receive coil. The patient has retained leads from a previous pacemaker removal. Which of the following are true?
None of the choices are true
There is an increased risk of magnetophosphenes in our patient
The patient has an increased risk of the static magnetic field moving the leads out of place
The patient has an increased risk of the leads heating up
None of the choices are true
What mode of operation provides a minimal fixed limit for the dB/dt and B1+rms?
Normal operation mode
FPO:B
First-level controlled operation mode
Second-level controlled operation mode
FPO:B
When a linear ferrous object is exposed to a static magnetic field that has a B0 that is vertical and is at isocenter, the ferrous object will align___.
Horizontal
Vertical
Unpredictable
Vertical
Which of the following is the best solution at reducing hearing damage the patients during acquisition?
All of the choices
Properly placing earplugs in a patient’s ears and putting additional towels around their head
Using both earplugs and a headset
Make sure earplugs are placed properly
All of the choices
Which of the following would we expect to be a threat associated with only the static magnetic field?
Steel IV pole
Titanium knee replacement
Earplugs
316l stainless steel wheelchair
Steel IV pole
A patient has a hip replacement and is undergoing a hip MRI exam. Which of the following is the most possible event to occur in our patient?
Translational force due to the static magnetic field
Rotation of the object due to the static magnetic field
Peripheral nerve stimulation in the implant
The production of hotspots around the implant
The production of hotspots around the implant
Which area would present the highest rotational force on a ferrous object?
A
Heating in our patient is dependent on which of the following? Select all that apply.
Tissue conductivity
Slice thickness
Tissue permittivity
Perfusion of exposed tissue
Tissue conductivity
Tissue permittivity
Perfusion of exposed tissue
You have reached your SAR limit and cannot continue scanning. What can be done to reduce your SAR?
Decrease TE
Add more slices
Decrease receiving bandwidth
Increase flip angle
Decrease receiving bandwidth
The pressure that builds up in the scan room due to a malfunctioned quench can cause which of the following? Select all that apply pressure in the MRI room.
Magnetophosphenes
Ruptured eardrums
Hypothermia
Pressure locking of inward opening doors
Ruptured eardrums
Pressure locking of inward opening doors
A patient has an unknown embolization coil for cerebral aneurysm. What is the risk of scanning this patient at 3T?
Scan
Low Risk
Moderate Risk
Don’t scan
Scan
The patient develops a headache after receiving gadolinium contrast. This is considered which of the following?
A non-allergic reaction
An allergic reaction
A non-allergic reaction
Which of the following is true of Zone 2? Select all that apply.
Offers direct access to Zone 4
Contains ferrous quarantine areas
Patients are screened in this area
Ferrodetection systems can be contained in zone 2
Contains ferrous quarantine areas
Patients are screened in this area
Ferrodetection systems can be contained in zone 2
When moving from 1.5 Tesla to 3 Tesla, the force of magnetism is ___.
10 times stronger
Inverse Square
Doubled
Quadrupled
Doubled
What are the minimum criteria for becoming an MR safety officer?
You must be an MRI technologist
Must be working in a medical imaging department
You must be a leader in the MRI department
There are no specific criteria except having an extensive understanding of MRI safety
There are no specific criteria except having an extensive understanding of MRI safety
1 L of liquid helium converts to approximately how many liters of helium gas?
700L
2000L
1L
200 L
700L
Which of the following would we expect to produce the largest susceptibility artifact in our image when scanning a lumbar spine?
Titanium left hip replacement
Copper T IUD
316L lumbar screw
405L stainless steel aortic stent
405L stainless steel aortic stent
For implants that are strongly ferromagnetic, a concern is that:
Electrical induction due to the principle of Faraday’s Law
Magnetic translational and rotational forces on the implant that might move or dislodge the device from its implanted position
Peripheral nerve stimulation
The static magnetic field does not itself pose a threat to any implant
Magnetic translational and rotational forces on the implant that might move or dislodge the device from its implanted position
Which of the following situations will offer the increased risk of heating within our patient?
A 6 ft patient with a retained lead in their chest undergoing a lumbar spine MRI with a receive-only coil
A 5 ft 4 in a patient with aneurysm clips and a cardiac stent undergoing an MRI brain exam with a receive-only coil
A 5 ft 10 in a patient with Harrington rods undergoing an MR foot exam with a receive-only coil
A 6-foot patient with retained leads in their chest undergoing a knee MRI with a transmit-receive coil
A 6 ft patient with a retained lead in their chest undergoing a lumbar spine MRI with a receive-only coil
Which of the following would be considered an allergic reaction to gadolinium contrast?
All of the choices
Swelling
Sneezing
Hives
Swelling
Sneezing
Hives
Sternal wires have an increased risk of burning our patients when exposed to RF.
False
True
False
Which of the following will produce the majority of the heat a patient will experience during an MRI?
Time-varying RF field
Static magnetic field
Time-varying gradient field
Time-varying RF field
You are scanning a patient in normal operating mode and using a receive-only RF coil. What is the maximum estimated RF dose your patient will receive?
10 W/kg
4 W/kg
1 W/kg
2 W/kg
2 W/kg
Which of the following situations has the highest likelihood of inducing cardiac stimulation in our patient?
A 5 ft 4 in a patient with a mechanical heart valve undergoing a lumbar MRI exam
A 6 ft 1 in a patient with retained leads in the chest undergoing an MRI pelvis exam
a 5 ft patient with a long stent in their ascending aorta undergoing an MRI brain exam
A 4 ft 1 in a child with braces undergoing an MRI cervical spine
A 6 ft 1 in a patient with retained leads in the chest undergoing an MRI pelvis exam
According to the ACR Manual on MRI Safety, who can provide basic MR screening on a patient?
All of the choices
Level 1 MR personnel
Level 2 MR personnel
Non-MR personnel
Level 1 MR personnel
Level 2 MR personnel
Non-MR personnel
Which of the following would promote a higher risk to a pregnant patient who needs an injection of gadolinium contrast for their MRI?
Receiving a macrocyclic agent
Receiving a linear ionic agent
Receiving a linear non-ionic agent
Receiving a linear non-ionic agent
A patient is only given a headset to reduce the noise in MRI. This is sufficient to protect from any hearing damage.
False
True
False
Which of the following increase the risk of a patients developing an allergic reaction to gadolinium contrast?
All of the choices
History of other severe allergic reactions to foods
Prior history of iodinated contrast reaction
Prior history of gadolinium reaction
History of other severe allergic reactions to foods
Prior history of iodinated contrast reaction
Prior history of gadolinium reaction
Movement through the static magnetic field is limited to which of the following according to the IEC?
1 T / s
3 T/ s
20 T/s
10 T/s
3 T/ s
Which of the following is true in the ACR Manual on MRI Safety? Select all that apply
It is recommended that a ferrodetector be located immediately outside of Zone 4
Handling codes should be performed in Zone 2
Ferrous objects such as non-MR conditional O2 tanks can be stored in any Zone except Zone 4
Patients should be changed in zone 2
Handling codes should be performed in Zone 2
Patients should be changed in zone 2
Induced current in a patient can be described by which of the following?
Lenz’s force
Ohm’s law
Faraday’s law of induction
Planck’s law
Faraday’s law of induction
Which of the following is recommended to be removed prior to an MRI exam according to the ACR Manual on MRI Safety?
Shirt and pants only
Only area being scanned
All jewelry must be removed what clothes can stay on
All jewelry and clothes are recommended to be removed prior to MRI exam
All jewelry and clothes are recommended to be removed prior to MRI exam
The MRSO is authorized to make decisions to scan a patient based on the diagnosis and reason for the exam.
False
True
False
Arrhythmogenesis potential can be produced at which of the following?
Scanning a brain with retained cardiac leads
Scanning a cardiac MRI with a heart valve
Scanning a foot with a transmit-receive coil
Scanning in the abdomen with a cardiac stent
Scanning a brain with retained cardiac leads
When considering only threats associated with the static magnetic field, which one of the following would we be most concerned about?
Nitinol stent
Small steel fragment in a patient’s eye
Titanium hip replacement
316l pacing lead
Small steel fragment in a patient’s eye
An implant must be greater than ____cm in size in order to produce enough electrical fields to cause a patient burn.
4
2
1.5
3
2
According to the ACR Manual on MRI Safety, which of the following can be performed on patients who cannot fill out an MR screening form? Select all that apply.
Use a metal detector to identify any heart implants
Visually examine a patient for any deformities, injury areas, or areas of surgery
Radiograph any suspicious areas of injury or surgery
Perform head and chest radiograph
Visually examine a patient for any deformities, injury areas, or areas of surgery
Radiograph any suspicious areas of injury or surgery
Perform head and chest radiograph
What are common artifacts seen on an ECG when performing an MRI exam?
Lower blood oxygen levels
Decrease blood pressure
Magnetohydrodynamic effect
All of the choices
Magnetohydrodynamic effect
Which of the following is not an allergic reaction?
Hives
Headache
Rash
Difficulty breathing
Headache
Gadolinium retention is only seen with unstable gadolinium-based agents.
False
True
False
The quench vent outside should have a clearance of ____ feet around the pipe.
15
25
10
50
25
A machine is considered MR conditional and will be placed in an MRI suite. It cannot exceed 400 Gauss. Where can we place this in the MR suite? Select all that apply.
D
C
B
A
D
C
B
A patient has cold cryogen comes in contact with tissues, what can occur?
Nothing
Energy deposition
2nd degree burns
Frostbite
Frostbite
If helium gas is released into the scan room, air can be displaced. This can cause what?
Asphyxiation
Magnetophosphenes
Explosive conditions
Frostbite
Asphyxiation
Which of the following active implants have a lower risk of increased heating?
Bone growth stimulator
Vagal stimulator
Leadless pacemaker
Pacemaker
Leadless pacemaker
The time-varying magnetic field describes which of the following? Select all that apply.
RF field
Time-varying gradient field
Static magnetic field
RF field
Time-varying gradient field
Which of the following will help us determine translational forces on objects?
RF drop off Plot
Gradient distribution plot
Isogauss plot
Magnetic spatial gradient
Magnetic spatial gradient
It is known that there is a flammable risk associated with a quench that releases cryogen into the room. This occurs because helium is flammable.
False
True
False
During a quench, the magnetic field drops dramatically over a time of approximately 1 minute. What can occur in our patient because of this?
Asphyxiation
Frostbite
Hypothermia
Magnetophosphenes
Magnetophosphenes
Which of the following offers the largest threat of burns when exposed to an MRI acquisition at 3T?
A patient who is 5 ft 4 in being scanned for an MRI of the brain who has an MR conditional aneurysm clip in their brain
A patient who is 5 ft 8 in tall is undergoing an MRI of the lumbar spine and has a hip replacement
A foot MRI with a transmit-receive coil with a patient who is 6 ft 4 and who has a retained pacemaker lead measuring 13 cm
A patient who is 5 ft 3 is undergoing an MRI of the abdomen who has a retained bladder lead measuring 10 cm
A patient who is 5 ft 3 is undergoing an MRI of the abdomen who has a retained bladder lead measuring 10 cm
Transmetalation has the highest occurrence with which of the following?
Macrocyclic ionic
Macrocyclic non-ionic
Linear ionic
Linear non-ionic
Linear non-ionic
Which of the following would be considered MR safe?
A carbon fiber slide board
A titanium localization needle
A tourniquet for IV starts
An aluminum wheelchair
A tourniquet for IV starts
Which of the following can be used as a heat sink?
A piece of aluminum foil
An ice pack
A piece of 100% cloth
A 1 cm pad
An ice pack
A patient is complaining of being warm in the scanner. What can be done to reduce their heating?
Decrease Echo train length
Increase signal averages
Decrease TR
Increase receiving bandwidth
Decrease Echo train length
We are scanning at 1.5 T and a patient has an abandoned lead in their chest. What lead length would promote the highest heating in that lead?
25 cm
5 cm
2 cm
13 cm
25 cm
According to the ACR Manual on MRI Safety, the exiting quench pipe outside a facility is considered to be in what zone?
Zone 2
Zone 1
Zone 3
Zone 4
Zone 3
A patient is renal impaired and needs an MRI with and without contrast. Which of the following agents would be the best choice to give them?
Macrocyclic agent
Linear non-ionic agent
Macrocyclic agent
According to the ACR Manual on MRI Safety, how often should policies be reviewed?
Weekly
Quarterly
Semi-annually
Annually
Annually
Which of the following are potential biological issues associated with a static magnetic field? Select all that apply.
Nystagmus
Vertigo
Nausea
Magnetohydrodynamic
Nystagmus
Vertigo
Nausea
Magnetohydrodynamic
Which of the following would be the best indicator of a static magnetic field threat?
Magnetic spatial gradient
Isogauss plot
Gradient distribution plot
None of the choices
Magnetic spatial gradient
Which of the following are ways to reduce the risk of nephrogenic systemic fibrosis?
All of the choices
Do not give to renal impaired patients
Deliver a lower dose
Utilize a stable gadolinium-based contrast agent
Do not give to renal impaired patients
Deliver a lower dose
Utilize a stable gadolinium-based contrast agent
Which of the following slew rates will describe a faster changing time-varying gradient?
100T/m/s
125 T/m/s
150 T/m/s
200 T/m/s
200 T/m/s
Which area would present the highest translational force on a ferrous object?
A
B
D
C
B
Which of the following would produce the largest susceptibility artifact when scanning a cervical spine?
A large steel hairclip in the area of the cervical spine
A copper necklace
Mechanical heart valve
A dental filling
A large steel hairclip in the area of the cervical spine
An object that is electrically conductive, but not ferrous is moving through the magnetic spatial gradient. Opposing magnetic forces are produced in that object. This can be explained by what?
Lenz’s Force
Ohm’s law
Planck’s law
Lenz’s Force
Pregnant employees cannot work in an MRI environment.
False
True
False
What unit of measurement is used to measure force product?
G / cm
G / cm squared
T^2 / m
T / m
T^2 / m
We are scanning at 1.5T, which of the following implants would have the greatest chance of burns?
10 cm internal wire
25 cm internal wire
5 cm internal wire
15 cm internal wire
25 cm internal wire
Which of the following would classify as a non-MR personnel?
MRI physicist
Attending radiologist
Security
MRI technologist
Security
According to the ACR Manual on MRI Safety, Level 1 MR personnel have access to which of the following zones? Select all that apply.
Zone 4
Zone 3
Zone 1
Zone 2
Zone 4
Zone 3
Zone 1
Zone 2
Which of the following situations would promote the highest risk of an object reacting to the static magnetic field?
A 5 ft 7 inpatient for a brain MRI with a lumbar fusion
A 5 ft 7 inpatient for a lumbar spine with an unknown GI clip
A 5 ft 9 inpatient for a cervical spine MRI with an unknown cardiac stent
All of the choices are a risk
A 5 ft 7 inpatient for a lumbar spine with an unknown GI clip
Which of the following is used to reduce the fringe field?
Shimming coils
The time-varying gradients coils
RF transmitter
Shielding
Shielding
The area that holds the highest heating potential during an exposure is at which of the following?
Near field
Opening to the gantry
Far field
Near field
Which of the following agents has not demonstrated gadolinium retention?
All of the choices have demonstrated gadolinium
Macrocyclic ionic
Linear ionic
Linear non-ionic
All have demonstrated retention