EX 1 Flashcards
Which of the following holds the least threat in terms of biological threat to the patient?
Static magnetic field
Time-varying gradient field
Time-varying RF field
Time-varying gradient field
When evaluating for concerns associated with the time-varying gradient field, which implant listed below is the most concerning?
Deep brain stimulator
Cardiac stent
Epicardial pacing leads
AAA repair
Deep brain stimulator
What is the half wavelength for a 1.5 T unit?
60 cm
25 cm
5 cm
12 cm
25 cm
Which of the following are true of 1.5 T MR units vs. 3.0 T? Select all that apply.
Implants that are safe at 3.0 T do not mean that they are safe at 1.5 T
Small metallic passive objects are safe at 3.0 T and not at 1.5 T
Ferrous objects show more attraction at 3.0 T vs 1.5 T
Heating in the pacemaker leads not connected to a generator is higher at 3.0 T than 1.5 T
implants that are safe at 3.0 T do not mean that they are safe at 1.5 T
Ferrous objects show more attraction at 3.0 T vs 1.5 T
All the following are true of screening patients with a ferromagnetic detector except?
Any objects that are metal or electrically conductive will be detected by a ferromagnetic detector.
They provide a higher level of detecting MR threats when compared to a metal detector.
It will only detect objects that are attracted to a magnetic field.
A ferrous object must be moving through the ferromagnetic detector field in order to be detected.
Any objects that are metal or electrically conductive will be detected by a ferromagnetic detector.
When advancing a patient into the bore, a patient with a pain pump complains of discomfort and like the device is moving within them. Once you stop moving the table, the discomfort stops as well. This is most likely caused by what?
Ohm’s law
Lorentz forces
Lenz forces
Lenz forces
A patient is having an MR lumbar spine scan in normal mode. We know that the whole body SAR will not exceed which of the following?
1.0 W/kg
4.0 W/kg
2.0 W/kg
3.0 W/kg
2.0 W/kg
What is the half wavelength for a 3.0 T unit?
12 cm
25 cm
5 cm
30 cm
12 cm
5,000G is equal to _____ T.
0.5T
1T
2T
0.25T
0.5T
Which of the following is true of the MR screening process according to the ACR Manual on MRI Safety? Select all that apply.
A written MR screening process is acceptable by a level 1 MR personnel as long as a level 2 MR personnel provides a verbal or interactive MR screening as well
A patient should be screened by at least one level 2 MR personnel verbally or interactively
Level 1 and 2 MR personnel need to have a more comprehensive MR screening process than used with patients
A patient should be MR screened twice
A written MR screening process is acceptable by a level 1 MR personnel as long as a level 2 MR personnel provides a verbal or interactive MR screening as well
A patient should be screened by at least one level 2 MR personnel verbally or interactively
A patient should be MR screened twice
What is the limit of the static magnetic field for patients <1 month old?
4T
8T
3T
2T
4T
Which of the following is true of tattoos? Select all that apply.
The strong static field can erase fresh tattoos
Skin can be twisted by the static magnetic field
Can rip out tattoos
Can cause a burn
Can cause a burn
What is true of an MR screening sheet? Select all that apply.
All the answers must be marked “yes” or “no”
Anyone entering zone 2 must have a sheet filled out prior to entering it
A Level 1 and 2 personnel will have a different sheet filled out than a patient
All the answers must be marked “yes” or “no”
Select the correct MR Unsafe symbol. Select all that apply.
black w/red
black w/black
What is the FDA limit of the static magnetic field for patients >1 month old?
2T
4T
8T
10T
8T
An Essure coil is made of 316L stainless steel, platinum, iridium, and nickel-titanium alloy. Which of the following statements is true?
An Essure coil is ferrous and may demonstrate some torquing while in the static magnetic field.
An Essure coil is ferrous and will demonstrate some artifacts when imaging the implant.
An Essure coil is non-ferrous and may demonstrate some artifact when imaging the implant.
An Essure coil is non-ferrous and may demonstrate some artifact when imaging the implant.
Which of the following is true when scanning pregnant patients?
Stay in normal mode
Scanning at 1.5 T suggested
Communicate with patient
All of the choices
Stay in normal mode
Scanning at 1.5 T suggested
Communicate with patient
Peripheral nerve stimulations are caused by an electric field that exceeds ____.
0.4 V/m
4.3 V/m
2.2 V/m
1.1 V/m
2.2 V/m
n order for the static magnetic field to be a true threat, an object could? Select all that apply.
Contain steel or iron
Contain 316L stainless steel
Be electrically conductive
Enter the MR environment
Contain steel or iron
Enter the MR environment
The ICNIRP states that moving through a field strength above ______ may be high enough to produce vertigo and other sensory perceptions like nausea or magnetophosphenes.
1.0 T
4.0 T
2.0 T
3.0 T
2.0 T
The ICNIRP sets an occupational dose of ____ to the head and torso.
Spatial peak magnetic flux density of 6 T
Spatial peak magnetic flux density of 2 T
Spatial peak magnetic flux density of 1 T
Spatial peak magnetic flux density of 4 T
Spatial peak magnetic flux density of 2 T
The quench vent outside the MR facility is inspected by who?
MR Technologist
Manufacturer engineer
MRMD
Facility engineer
Facility engineer
Which of the following is typically labeled non-MR personnel? Select all that apply.
Local firefighter
Family of patient
Referring physicians
Security
Patient transport
Local firefighter
Family of patient
Referring physicians
Security
Patient transport
A proximity burn occurs when?
When a electrical conductive material is placed on our patient.
When a patient’s skin forms a conductive loop.
When an ECG wire forms a loop.
A patient’s skin is in contact with the gantry.
A patient’s skin is in contact with the gantry.
All the zones need to be represented with signage except?
Zone 4
Zone 2
Zone 1
Zone 3
All need to be represented, but zone 1 may be optional depending on the auditing body
All need to be represented, but zone 1 may be optional depending on the auditing body
PNS occurs in our patient due to which of the following processes?
Faraday’s law
Ohm’s law
Lenz Law
Lorentz forces
Faraday’s law
A patient is exposured to 99dBA and has earplugs with an NRR of 29. What is the level of noise the patient will experience?
88dBA
70dBA
85dBA
90dBA
88dBA
(29-7)/2=11. 99-11 = 88dBA
A patient had an MRI a month ago and had suffered a moderate allergic reaction. The patient is in need of another MR with contrast tomorrow. How can we reduce the risk of this…
Give the patient Xanax prior to the exam
Have a code blue team on standby in zone IV for the duration of the exam
Give a half dose of GBCM
Give steroids to the patient 6 hours before their exam
Give steroids to the patient 6 hours before their exam
A large ferrous object is stuck against the MRI unit and no one is in harm’s way. What should you do?
Pull the object off of the unit yourself
All of the choices
There is no need to report this event since it did not hurt anyone
Contact trained personnel to remove the object
Contact trained personnel to remove the object
This individual manages day-to-day MR safety issues, enforces policies, and provides MR safety knowledge.
MRMD
MRSO
MRSE
MRSO
What makes the time-varying gradient field (TVGF) different than the time-varying RF field (TVRF)?
The TVGF will produce resonance in the patient.
The TVGF uses a faster changing magnetic field than the TVRF.
The TVGF uses a slower changing magnetic field than the TVRF.
The TVGF will induce more heating in the patient than the TVRF.
The TVGF uses a slower changing magnetic field than the TVRF.
Gadolinium contrast has been found in the body in what form? Select all that apply.
Water soluble
Non-water soluble
Free gadolinium is not bound to anything
Water soluble
Non-water soluble
Which of the following are true of the copper T or copper 7 IUD? Select all that apply.
Can produce significant heating
Can become dislodged
Contains thin coiled copper wires
Produce large artifacts
Contains thin coiled copper wires
If a cryogen comes in contact with skin, what will happen?
Explode
Combust
Frostbite/necrosis
Nothing, in its gas form
Frostbite/necrosis
According to the IEC, what is the limit for the static magnetic field for clinical MRI?
200 mT
8 T
400 mT
4 T
8 T
A patient is complaining of discomfort from high SAR during a fast spin echo. What can be done to make them more comfortable?
Increase the flip angle
Increase the receiving bandwidth
Decrease the TR
Decrease the echo train length
Decrease the echo train length
Where would we expect to see the maximum peripheral nerve stimulation in our patient who is having an MR lumbar spine exam performed head first?
Lumbar spine
Thighs
Feet
Abdomen
Thighs
Which of the following IUD contain ferrous material? Select all that apply.
Mirena IUD
Copper T
Copper 7
None of the choices
None of the choices
Which of the following statements are true of gadolinium contrast? Select all that apply.
It is hypothesized that gadolinium retention occurs due to it following pathways that other metals do, such as iron and calcium.
Gadolinium is not linked to NSF.
Gadolinium retention has been linked to gadolinium-associated plaques.
Cases of NSF have been increasing over the last 5 years
It is hypothesized that gadolinium retention occurs due to it following pathways that other metals do, such as iron and calcium.
Which of the following agents are the most stable?
All are equally stable
Macrocyclic
Non-ionic linear
Ionic linear
Macrocyclic
Why is it recommended to tape or wrap gauze around jewelry?
To make sure translational force does not occur
To reduce the magnetic susceptibility
To reduce contact with the skin
To make sure rotational force does not occur
To reduce contact with the skin
According to the ASTM F2503 document, the MR environment refers to what?
Anything within the 5 Gauss line
An area that contains the Faraday shield and the 5 Gauss line
Zone 3 and Zone 4
Zone 4
An area that contains the Faraday shield and the 5 Gauss line
Which of the following issues are most likely to occur when exposing a neurostimulator to RF and cause the most immediate threat to our patient?
Rotational force
Magnophosphenes
Translational force
Burns
Burns
The quench vent in the MR room should be inspected by who?
MRMD
MR technologist
Manufacturer engineers
Facility engineers
Manufacturer engineers
Which of the following is true of gadolinium retention? Select all that apply.
It is a result of free gadolinium in the patient
It is seen in only renal compromised patients
Every linear agent produces the same amount of retention in the brain.
It is seen in bone and brain tissue
It is a result of free gadolinium in the patient
What can be done to reduce pressure in an MR scan room during a quench with a defective room vent and a door that opens into the scan room? A patient is in the room.
Break the window to zone IV
Open the door to zone IV
Drill a hole into the wall to zone IV
Wait 20 minutes for the pressure to dissipate
Break the window to zone IV
A patient is complaining of discomfort during a single shot fast spin echo sequence. What can be done to make them more comfortable?
Increase the phase encoding resolution
Decrease the TR
Use parallel imaging
Scan only in the axial plane
Use parallel imaging
What are ways to reduce the negative effects associated with the time-varying gradient field? Select all that apply.
Increase the number of RF pulses
Increase the field strength
Decrease the acquisition speed (switching magnetic fields)
Decrease the strength of the gradient field magnetic slope (gradient amplitude)
Decrease the acquisition speed (switching magnetic fields)
Decrease the strength of the gradient field magnetic slope (gradient amplitude)
Which of the following implants hold the most thermal risk to a patient?
Gallbladder clip
Abandon pacemaker lead
Pacemaker lead attached to a generator
Bone screw
Abandon pacemaker lead
Which of the following is most likely experienced by the patient being exposed to a fast time-varying gradient field?
Translational force
Lenz’s effect
Tingling
Burn
Tingling
When handling a code in the MR environment, which of the following are NOT best practices according to the ACR?
A patient should be completely stable prior to removing a patient from zone 4
It is suggested that a patient be brought to zone 2 but can be in zone 3 if necessary to resuscitate the patient
All the choices should not be done
The patient must be removed from zone 4 before calling a code
A patient should be completely stable prior to removing a patient from zone 4
Select all that will produce/influence magnetophosphenes from the static magnetic field.
Rate of motion through a magnetic field
Patient sex
Weight of patient
Strength of field strength
Rate of motion through a magnetic field
Strength of field strength
What type of contrast is Dotarem?
Non ionic, macrocylic
Ionic, non ionic
Ionic, macrocylic
Linear, macrocylic
Ionic, macrocylic
Which of the following are considered long-term effects of gadolinium contrast media? Select all that apply.
Anaphylaxis
Emesis
Nephrogenic systemic fibrosis
Gadolinium associated plaques
Nephrogenic systemic fibrosis
Gadolinium associated plaques
The change in pressure in the MRI scan room can do what?
Cause condensation to accumulate on the patient
Detach the MR table
Increase the static magnetic field
Pressure locking of access to zone IV
Pressure locking of access to zone IV
Which of the following is used to calculate renal function? Select all that apply.
Platelet count
Creatinine
Patient white blood cell count
D-dimer
Creatinine
n order for the time-varying RF field to be a threat, an object could? Select all that apply.
Be electrically conductive
Non-ferrous and non-metallic
Form a conductive loop
Be >2cm in size
Be electrically conductive
Form a conductive loop
Be >2cm in size
Which of the following agents yields the best chance for transmetalation to occur?
Linear ionic
Macrocyclic ionic
Linear non-ionic
Macrocyclic non-ionic
Linear non-ionic
During a malfunctioned quench what would we expect to see? Select all that apply.
Increase in temperature
Decrease in room pressure
Changing magnetic field
Explosion risk
Changing magnetic field
Explosion risk
Which of the following has theoretically been deemed a threat to a patient with a heart valve containing non-magnetic metallic disks or leaflets at ultra-high field strengths?
Antenna effect
Translational force
Rotational force
Lenz’s effect
Lenz’s effect
Transient dyspnea:
Is seen in repeat contrast reactions
Is associated with chronic obstructive pulmonary disease and noted after the administration of any GBCM.
Describes the manifestation of transient severe respiratory motion-related artifact in the arterial phase after the administration of gadoxetate disodium.
Is an acute reaction after the administration of gadoxetate disodium and requires immediate intervention
Describes the manifestation of transient severe respiratory motion-related artifact in the arterial phase after the administration of gadoxetate disodium.
A patient has an external fixation device that is labeled as MR conditional. All the conditions are met and you scan the patient. The patient says that the external fixation device starts vibrating. This is caused by which of the following?
All of the choices
Time-varying RF field
Static magnetic field
Time-varying gradient field
Time-varying gradient field
A manufacturer’s instructions define that an implant can be scanned at 2 W/kg for 15 min. What does this mean?
The patient can be scanned only in normal mode for a total exam time greater than 15 min.
Patients can be scanned in first-level as long as the total exam time is less than 7.5 min.
The patient can be scanned in first-level controlled mode as long as the individual sequence does not exceed 15 min.
The patient can be scanned in normal mode as long as the individual sequence does not exceed 15 min.
The patient can be scanned in normal mode as long as the individual sequence does not exceed 15 min.
Which of the following is true of gadolinium-associated plaques? Select all that apply.
This is a common occurrence in MRI
It is the same thing as NSF
It occurs when gadolinium is ingested
It is not related to renal compromised patients
It is not related to renal compromised patients
When evaluating for concerns associated with the time-varying gradient field, which implant listed below is of most concern?
Hip replacement
All the choices
MR Conditional insulin pump
Cardiac pacemaker
Cardiac pacemaker
Anthropogenic effects of gadolinium would most likely be seen where?
Cities with large healthcare facilities
Rural areas
Towns with many rivers and lakes
Cities with large healthcare facilities
A patient is having an MR brain scan in first-level controlled mode with a receive-only coil. We know that the whole body SAR for a head will not exceed which of the following?
8 W/kg
2.0 W/kg
4.0 W/kg
3.2 W/kg
3.2 W/kg
All the following except what makes a patient more prone to an allergic reaction to gadolinium?
Allergy to CT contrast
Seasonal Allergies
High Blood Pressure
Prior Gadolinium Reaction
High Blood Pressure
Guidewires can produce heating in the patient due to which of the following?
Reflective burn
Proximity burn
Antenna effect
A loop of conductive tissue
Antenna effect
What needs to be in site when complying with the line of sight rule defined in the ACR Manual on MRI Safety? Select all that apply.
Patient
Door to Zone 4
Console
Door to Zone 3
Patient
Door to Zone 4
Console
A patient is complaining of severe discomfort and tingling during a GRASS sequence in normal control mode. What can be done to make the patient more comfortable?
Increase the echo train length
Scan in first level control mode
Increase the flip angle
Use a spin echo sequence
Use a spin echo sequence
As we approach the MRI unit, which of the following occur without any time-varying magnetic fields activated? Select all that apply.
Translational force increases
Rotational force increases
Non-ferrous objects are attracted to the MR unit
Patients may experience burns
Translational force increases
Rotational force increases
Non-ferrous objects are attracted to the MR unit
An MR Conditional implant or device should minimally address which of the following per the ASTM guidelines. Select all that apply.
Patient position
Static magnetic field
Radiofrequency fields
Switched gradient magnetic fields
Static magnetic field
Radiofrequency fields
Switched gradient magnetic fields
What type of gadolinium contrast has been shown to cause falsely low serum calcium laboratory values?
Linear non-ionic
Linear ionic
There is no correlation
Macrocyclic
Linear non-ionic
A patient is having an MR with IV-administered GBCM. This patient has sickle cell disease. Which of the following is true?
The risk of adverse effects to the patient is minimal and there is no reason to withhold administration.
Contrast media should not be given.
A GFR should be obtained prior to injection.
Patients should receive a hydration protocol and be pre-medicated.
The risk of adverse effects to the patient is minimal and there is no reason to withhold administration.
Which of the following is true of gadolinium and breastfeeding mothers? Select all that apply.
It is thought that gadolinium contrast may alter the taste of breast milk
Available data suggest that breast-feeding should be pumped and discarded for 24 hours after the intravenous dose
20% of the intravascular dose would be excreted into the breast milk within the first 24 hours
Gadolinium is found in breast milk in a stable and chelated form
It is thought that gadolinium contrast may alter the taste of breast milk
Gadolinium is found in breast milk in a stable and chelated form
The magnetohydrodynamic effect will influence what?
R wave
S wave
P wave
T wave
T wave
Which of the following are correct when using a metal detector to screening a patient for MR threats?
They are one of the most effective means of identifying risk in MR.
They are a must in ensuring the safety of our patients and are recommended by the ACR Manual on MRI Safety
They will only detect ferrous objects.
They can not determine what is ferrous or not.
They can not determine what is ferrous or not.
RF-induced heating in a patient or implant will depend on which of the following? Select all that apply.
Department policies
Position of the implant or patient
MR RF coil used
Overall MR field strength
Position of the implant or patient
MR RF coil used
Overall MR field strength
Select the correct MR Conditional symbol. Select all that apply.
yellow/black
white/black
Which of the following orthopedic implants would we expect to demonstrate the largest chance of a burn during an MR exam?
Lumbar Fusion
AAA repair
Hip Replacement
External Fixation System
External Fixation System
Which of the following locations are found in the MR environment? Select all that apply.
C
B
D
A
A
Which of the following issues could occur with an insulin/pain pump? Select all that apply.
Damage to the pump
Infusing a bolus of medication
Heating in leads
Damage to the pump
Infusing a bolus of medication
Select the correct MR Safe symbol. Select all that apply.
white/green
green/white
white/black
black/white
Which of the following are considered short-term (non-allergic or allergic reactions) effects of gadolinium contrast media? Select all that apply.
Swelling
Hives
Emesis
Nephrogenic systemic fibrosis
Swelling
Hives
Emesis
Which of the following will produce the largest artifact in the MR environment?
Nickel alloy AAA repair
Cobalt cardiac stent
Titanium clip
Steel L-spine cage
Steel L-spine cage
In order for cryogen to not harm a patient, what needs to happen?
The cryogen must be filtered to make it safe to breath
The cryogen should be vented underground
The cryogen needs to be warmed to room temperature
The cryogen needs to be vented outside
The cryogen needs to be vented outside
A patient is complaining of severe discomfort during a DWI sequence. What can be done to make the patient more comfortable?
Shortening the TR
Increasing image matrix
Perform a fast spin echo
Perform an SSFP sequence instead
Perform a fast spin echo
Which of the following reactions are most common when administering MR contrast?
Gadolinium associated plaques
Allergic reactions
NSF
Physiologic reactions
Physiologic reactions
An emergent quench can take approximately how long?
2-4 minutes
30 seconds -1 minute
10 seconds
5-15 minutes
30 seconds -1 minute
Which of the following increases the odds that a patient will develop NSF after injection of gadolinium contrast? Select all the apply.
Hypertension
Renal disease
Patients over 60 years older
Migraines
Hypertension
Renal disease
Patients over 60 years older
What is the best way to prevent NSF? Select the single best answer.
Don’t give gadolinium contrast to patients who are in renal failure
NSF cannot be prevented
Perform dialysis on the patient prior to the gadolinium contrast injection
Hydrate patient prior to gadolinium injection
Don’t give gadolinium contrast to patients who are in renal failure
An MR fetus study is being performed. What field strength should be used to scan this patient according to the FDA?
< 4.0 T
Only 0.5 T
>3.0 T
>8.0 T
< 4.0 T
Which of the following is considered an allergic reaction to gadolinium contrast media? Select all that apply.
Swelling
Elevated eGFR
Headache
Hives
Swelling
Hives
Which of the following are sensations that occur from the time-varying gradient field?
Pain
Tingling
All of the choices
Twitching
Pain
Tingling
Twitching
A sequence is run with peak unweighted sound pressure of 120dB. Is this within IEC regulation?
Yes
No
Yes
peak is 140
Which of the following reasons why a tissue expander may be contraindicated for MRI?
These implants may contain magnetic components that can be attracted to the MR unit.
These implants contain large conductive metals that can heat up during acquisition.
All of the choices
These implants can produce uncomfortable peripheral nerve stimulation.
These implants may contain magnetic components that can be attracted to the MR unit.
The ICNIRP sets an occupational dose of ____ to the limbs.
Up to 10 T
Up to 2 T
Up to 4 T
Up to 8 T
Up to 8 T
Which of the following images demonstrates an MR unit that is shielded?
B
A
B
Which of the following will influence translational force? Select all that apply.
Strength of the magnetic field strength
Magnetic susceptibility
Mass of the object
Spatial gradient magnetic field
Strength of the magnetic field strength
Magnetic susceptibility
Mass of the object
Spatial gradient magnetic field
