Rite ad 4 Flashcards
Emesis after a contrast media reaction is considered what type of adverse reaction?
A non-allergic reaction to contrast media
Identify the ferromagnetic threat. Select all the correct answers
Scissors
Metal hemostat
Scalpel
A _________field of view (FOV) will utilize a steeper frequency encoding gradient. This will promote peripheral nerve stimulation.
Smaller
The quench is not experienced right away, after about _______________, the cryogen is released from the MRI unit through the quench vent.
15-20 seconds
Which of the following is true of all types of stainless steel? Select all the correct answers.
All will cause artifacts in our image
Which of the following is true of a gadolinium contrast osmolarity?
It is greater than blood
Which of the following stainless steel is non-ferrous?
Austenitic
Which of the following personnel can enter zone 3 and 4 but not escort a patient into zone 4, according to the ACR Manual on MRI Safety?
MR personnel level I
The rapid turning on and off of the gradient coil can produce which of the following events in our patient? Select all that apply.
Magnetophosphenes
Peripheral nerve stimulation
A patient undergoing an MRI exam is given an ice pack to reduce heat. Which of these methods is the patient using to regulate their increased heating?
Conduction
Which of the following are NOT recommended by the ACR Manual on MRI Safety?
Metal detector
This individual must have an in-depth understanding of the risks associated with the MRI environment, according to the ACR Manual on MRI Safety.
Level 2 personnel
What is the risk with a non-ferrous pain pump?
Lenz’s force
A patient will change into a gown in most hospital settings within this zone, according to the ACR Manual on MRI Safety.
Zone 3
Zone 2
Zone 1
Zone 4
Zone II
In which ways can a patient self-regulate their temperature when they get overheated? Select all that apply.
Evaporation
Radiation
Which of the following are considered ferrous materials? Select all the answers that are correct.
Steel
Cobalt
Nickel
What is the maximum allowable strength of the gradient coils for a given sequence called?
Maximum gradient peak
Which of the following are units of measure for the static magnetic field (BO)?
Tesla
In a superconducting magnet, what makes the chirping noise
The chiller
All MR medical directors should report incidents to which of the following within one business day of an adverse event?
FDA Medwatch Program
Gadolinium contains what kind of magnet susceptibility?
Paramagnetic
How many gauss are in one Tesla?
10,000
What organization has produced the terms used in MR labeling (MR Safe, MR Conditional, etc.)?
ASTM International
A ligand that cages a gadolinium ion is referred to as?
Macrocyclic bond
The electric fields associated with RF can cause what when exposing our patient?
Burning
Your patient has squeezed the ball and you have stopped imaging. When you enter the room your patient is concerned that their nose is burning. When the last sequence started they felt a tingling. The last sequence was a gradient echo sagittal. What is a probable cause of the feeling?
The patient is experiencing peripheral nerve stimulation
Which of the following require the minimal MR safety training according to the ACR Manual on MRI Safety?
MR Tech aid
The MRI technologist
A patient’s family member wanting to sit with the patient
The person being scanned
Level 1 MR personnel
The B1 refers to what?
The direction of the RF field
What unit of measurement is used for the SAR in MRI?
W/kg
Which of the following statements are true? Select all the correct answers.
The static magnetic field and time-varying fields can cause infertility
The static magnetic field and time-varying fields have been associated with teratogenesis
The static magnetic field and time-varying fields can cause an increase in spontaneous abortion
The static magnetic field and time-varying field exposure increase the chance of female offspring working in pregnant MR technologists
None
None
What type of MRI unit uses many bricks of magnets to produce a strong static field?
Permanent magnet
The 45-degree deflection of an implant is equal to what force?
1 gravity force
What group issued the ACR Manual on MRI Safety?
American College of Radiology
What type of MRI unit uses a coil of wire with a current running through it and a cryogen to help produce a strong magnetic field?
Superconducting magnetic
Which of the following statements are true when discussing MR safety?
Larger patients will heat up the most
When a patient undergoes an MRI exam and starts to perspire, what method is the body using to regulate the increased temperature?
Evaporative cooling
What types of cryogen are used in a dual cryogen system?
Helium
Nitrogen
Clothing labels are a good indicator if your patient’s clothes contain metal in the fabric.
True
False
False
What is the first thing that should be done for patients with a history of orbital trauma by a potential ferromagnetic foreign body?
Obtain plain x-ray orbit films
Where is a cryogen primarily located?
In the MR unit
Which of the following most likely would be considered a Level 1 MR personnel according to the ACR Manual on MRI Safety?
MR Tech aid
The MRI technologist
A patient’s family member wanting to sit with the patient
The person being scanned
MR Tech aid
This person is responsible for offering suggestions on MR protocol modifications, offering advice on MR Safety programs and MR Quality Assurance programs, providing a high level of advice on safety aspects of MR equipment, and reporting this information to the MRMD. This individual is typically a physicist.
MRSE
After about approximately__________, the magnetic field reaches zero after a quench
3-5 minutes
Pads placed between a patient and the side of the magnet can prevent a proximity burn.
True
False
True
How would gadolinium contrast appear on a T1-weighted image?
Bright
The control room is commonly found in what zone according to the ACR Manual on MRI Safety?
Zone 3
The ACR Committee on Drugs and Contrast Media concludes that patients receiving Group I GBCA’s should be considered at risk of developing NSF if any of the following conditions apply to the patient: (Select all that apply)
AKI
Severe or ESRD w/o dialysis
On dialysis
A ligand that attaches to a gadolinium ion in a chain like molecule is called what?
Linear
What is the name for the direction of magnetic flux densities produced by the static magnetic field?
B0
Unsafe active implanted devices in patients should never enter zone 3 but should definitely not ______.
Crossing the 5-gauss line
A deflection of 90 degrees due to translation force indicates how much force is experienced on the implant.
Undetermined
A patient begins to sneeze uncontrollably immediately after an injection of gadolinium contrast. This could be considered what?
Allergic reaction
Which of the following statements are not true according to the ACR Manual on MRI Safety?
Unscreened patients should not enter zone 3
Zone 4 is the responsibility of the level 2 personnel
The MR screening process for non-MR personnel and MR personnel should be the same
The MR screening process for non-MR personnel and MR personnel should be different
The MR screening process for non-MR personnel and MR personnel should be different
Which of the following answers best describes when an electrical current is produced in an electrically conductive material (wire, patient, etc) in an alternating magnetic field?
Faraday’s law of induction
A patient develops two hives on their chest after a gadolinium contrast injection. What type of adverse event is this considered?
Allergic reaction
Which of the following can reduce the risk of Lenz’s force with implanted devices in our patient?
Advance the patient slowly in the MR unit
The speed that it takes a gradient coil to activate and reach maximum strength is called what?
The rise time
Which formula are used to define the time-varying gradient magnetic fields?
dB/dt
Which of the following will influence the amount of heating produced from RF? Select all that apply.
Patient weight
Field strength
Flip angle
What does a cryogen do to the static magnetic field solenoid?
It reduces/eliminates resistance in wires
A gadolinium ion is attached to a molecule called a/an ______ so it can be excreted from a patient.
Ligand
Cryogen is designed to escape from the MR room through what?
Quench vent
Which of the following is true of non-MR personnel according to the ACR Manual on MRI Safety?
They must pass an MR safety screening process before entering zone 3
Which of the following will determine the amount of heating that a patient will receive? Select all that apply.
Patient mass
Patient’s overall surface area
Pulse sequence used
Which of the following describes the total dose of energy that a tissue receives during an entire exam?
Specific energy dose
During a quench, over a period of _________ minute(s), the magnetic field is changing. This can cause peripheral nerve stimulation or other biological effects associated with changing magnetic fields.
1
2
3
5
1
Common complaints in the MR environment due to the fast-changing gradient activations are (select all that apply)
Nystagmus
Dizziness
Nausea
Why are metal detectors not recommended in MR screening according to the ACR Manual on MRI Safety?
They are dependent on operator skill
They cannot detect small fragments well
All of the choices
They have varied sensitivity
They are dependent on operator skill
They cannot detect small fragments well
They have varied sensitivity
How much more heating does a 360-degree RF pulse have than a 180-degree RF pulse?
4 times more
According to the ACR Manual on MRI Safety, what zone is the MRI unit found?
Zone 4
Which of the following are considered time-varying magnetic fields?
RF and changing gradient magnetic field
The B1 field is found where?
90 degrees to the B0
The patient changing room for MRI patients is commonly found in the following zones according to the ACR Manual on MRI Safety.
Zone 2
Towels next to a patient’s ears are sufficient to lower noise.
True
False
False
The slope of the phase encoding gradient amplitude will determine how much resolution we will have in our image. Therefore a _____________ gradient slope will produce high-resolution images.
Steeper
Which of the following is used to measure patient heating in MRI?
Specific absorption rate
All of the following are true of a patient according to the ACR Manual on MRI Safety, except?
Patients should remove any ferrous objects prior to the MR exam
Patient can be screened and accompanied by Level 1 personnel into Zone 4
Patients must be verbally or interactively screened before entering the MR suite
Patients must be supervised by level 2 personnel for the entirety of the exam
Patient can be screened and accompanied by Level 1 personnel into Zone 4
According to the ACR Manual on MRI Safety, what zone is the quench pipe located OUTSIDE, a facility?
Zone 3
When electrical fields are produced in implants, the process of _________heating can result.
ohmic
The process of releasing a cryogen from the MR unit is called?
Quench
What is the difference between an allergic reaction to contrast media and an anaphylactic reaction?
Anaphylactic reactions are more serious
A macrocyclic agent refers to a gadolinium ion that is what?
A “caged in” gadolinium ion
The number of particles found in one liter of a solution is defined as what?
Osmolarity
The T wave in the cardiac cycle represents what?
Heart repolarization
The image matrix consists of a frequency and phase direction. When increasing these values, we will increase our resolution. This means that we will be increasing the slope of our gradient coils and this will _______________ the chances of peripheral nerve stimulation.
Increase
In order for cryogen to not harm a patient, what needs to happen?
The cryogen needs to be vented outside
What is the most common patient complaint post gadolinium contrast injection?
Headache
Inside the bore of the MRI unit, where would we expect the gradient coils to be found?
Surrounding the patient peripheral to isocenter
A headache after a contrast media injection is considered what possible adverse event.
Non-allergic reaction
What document has established guidelines for MR safety and best practices that are followed today in the US?
ACR Manual on MRI Safety
A patient receives an injection of gadolinium contrast and has pain at the injection site. What would this be considered?
A non-allergic reaction
An area that is outside of any MR department and is accessible to the general public is called what, according to the ACR Manual on MRI Safety?
Zone 1
_______________ states that as you run a current through a wire, a magnetic field is produced 90° to that current. It also explains that an electrical current will be produced in a wire placed in a changing magnetic field.
Faraday’s Law of Induction
A tester magnet should be how strong according to the ACR Manual on MRI Safety?
Equal or greater than 1000 gauss
The gradient coils are responsible for which of the following? Select all that apply.
Noise
Peripheral nerve stimulation
Which of the following describes when a non-ferrous, electrically conductive object is repulsed by a static magnetic field when moving through its magnetic flux?
Lenz’s force
The loud knocking noise in a MRI machine is produced only by the static magnetic field turning on and off.
False, the loud knocking noise is created by the gradients turning on and off quickly
Which of the following is true of a metal detector?
All the choices
They detect all conductive materials
They are sensitive to only ferrous objects
They are able to detect only metal substances
They are able to detect only metal substances
A technologist walks into the MRI room to check on a patient. As they do this, they stick their head into the scanner quickly. What can occur from this movement through the static magnetic field? Select all that apply.
Magnetophosphenes
Vertigo
Nausea
What is the cryogen used in MRI?
Helium
