EX 2 Flashcards by William Kerns

Who is responsible for maintaining the quench vent outside the site in zone 3?

Manufacturer engineer
Site engineer
MRI technologists
MRI Physicist

Site engineer

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Which provides us a more accurate understanding of RF exposure to our patient?

SED
Tesla
B1+rms
SAR

B1+rms

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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

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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

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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

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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

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Slew rate offers risks associated with which of the following?

Static magnetic field
Time-varying RF
Time-varying Gradient

Time-varying Gradient

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dB/dx refers to which of the following?

Time varying magnetic field
Patient Heating
Magnetic spatial gradient
Isogauss

Magnetic spatial gradient

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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

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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

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OSHA sets a safe noise level for occupational workers to what?

140dBA
99dBA
70dBA
85dBA

85dBA

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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

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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

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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

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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

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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

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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

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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

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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

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What is the center frequency for a 1.5T is approximately?

64 MHz
128 MHz
300 G/cm
224 MHz

64 MHz

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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

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Which of the following burns do not always occur at or near isocenter?

Resonance burns
Conductive loop burns
Proximity burns

Conductive loop burns

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Pressure build-up during an improper quench can cause a door opening ______ to be sealed and not open.

Outward
Inward

Inward

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The missile effect describes which of the following?

Translational forces
Peripheral nerve stimulation
RF Heating
Rotational forces

Translational forces

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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?

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

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

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

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