Rite ad 5 Flashcards
Which of the following is possible if a cryogen is released into the MR room?
Start snowing in the room
Start raining in the room
Have poor visibility
All of the choices
Start snowing in the room
Start raining in the room
Have poor visibility
A cryogen released in the scan room will do what to the room pressure?
Increase it
Not change it
Decrease it
Vary it
Increase it
Helium is very reactive?
True
False
False
What is hypothermia?
When the blood pressure decreases dramatically
When the blood pressure increases dramatically
When the body temperature gets dangerously warm
When the body temperatures get dangerously cold
When the body temperatures get dangerously cold
The gas ratio of helium is what?
1:2
200:1
1:1
700:1
700:1
If a cryogen touches a patient skin, what would happen?
Nothing
2nd-degree burn
Frostbite/tissue necrosis
Infection
Frostbite/tissue necrosis
How cold is helium in its liquid state?
500 Kelvin
-100 degrees Celsius
0 Kelvin
~4 Kelvin
~4 Kelvin
The change in pressure in the MRI scan room can do what to the patient during a malfunctioned quench?
Form a magnetic field around the scan table
Throw the patient around the room
Cause the room to shake
A patient may experience ear pain from increased pressure
A patient may experience ear pain from increased pressure
What occurs if a quench vent pathway fails?
Pressure within the MR scan room would increase
The static magnetic field will increase in strength
The gradient coils will be activated
The RF transmitter will emit a resonant frequency
Pressure within the MR scan room would increase
If a cryogen is released into the MR room, what could occur in the patient?
Asphyxia
Bronchitis
Neuropathy
Proximity Burn
Asphyxia
The degree that a tissue demonstrates T1 and T2 relaxation post contrast media injection refer to what?
Relaxivity
Osmolarity
Chelation
Viscosity
Relaxivity
Which of the following are contraindication(s) to the administration of a GBCA?
None of the above
Sickle-cell
Beta-blockers
Asthma
None of the above
Nephrogenic Systemic Fibrosis is caused by what?
When the gadolinium ion is excreted from the body quickly
When the gadolinium ion is excreted by the liver
When the patient is allergic to gadolinium contrast media
When a gadolinium ion breaks free from the ligand and remains in the body
When a gadolinium ion breaks free from the ligand and remains in the body
A patient receives many doses of gadolinium contrast over their lifetime. They come in for an MR brain and T1 shortening is seen pre-contrast in the dentate nuclei and basal ganglia. What is this called?
Retained gadolinium
Magnetohydrodynamic effect
NSF
Anthropogenic
Retained gadolinium
Normal kidneys should excrete all gadolinium contrast from a patient how quickly?
32 hr
6 hr
12 hr
24 hr
24 hr
A contrast media with a high relaxivity will do what when compared to a contrast media with a lower relaxivity?
It will produce more signal
It will produce less signal
It will produce more image noise
It will improve the resolution
It will produce more signal
A disease that may be connected with delivering gadolinium contrast to patients with compromised renal function is called?
Nephrogenic Systemic Fibrosis
Musculoskeletal fibrosis
Fibromyalgia
Gadolinuim deposition
Nephrogenic Systemic Fibrosis
Which of the following gadolinium contrast agents will demonstrate the highest risk of NSF in patients who are in renal failure?
Linear non-ionic contrast
Linear ionic contrast
Macrocyclic ionic contrast
Macrocyclic non-ionic contrast
Linear non-ionic contrast
The detection of gadolinium in the drinking water is called?
Gadolinium retention
NSF
Anthropogenic
Teratogenesis
Anthropogenic
The frequency of acute adverse reactions to GBCA is about______times higher in patients with previous reaction to GBCM.
3
0.06
5
8
8
What is the national standard formula for pediatrics and eGFR?
MSDS
CKD-EPI
SER-EGFR
Bedside Schwartz
Bedside Schwartz
Anthropogenic gadolinium can be described as what?
The influence of gadolinium on patients with renal insufficiency
When the accumulation of gadolinium occurs in the body
When gadolinium is found in the water supply
When the retention of gadolinium in specific tissues is present
When gadolinium is found in the water supply
A disease that causes fibrosis of the skin and organs of a patient who receives unstable gadolinium-based contrast media is called?
Nephrogenic Systemic Fibrosis
Musculoskeletal fibrosis
Fibromyalgia
Gadolinuim deposition
Nephrogenic Systemic Fibrosis
Which of the following is true if we increase the image matrix from 256×256 to 512×512?
We reduce peripheral nerve stimulation
Our phase encoding gradient would active a stronger magnetic gradient field
Our phase encoding gradients would activate a weaker magnetic gradient field
We reduce patient heating
Our phase encoding gradient would active a stronger magnetic gradient field
What is true of peripheral nerve stimulation?
An exam must be stopped if this occurs
It can cause discomfort to the patient
It is always life-threatening
All of the choices
It can cause discomfort to the patient
What is the FDA limit for the effects of peripheral nerve stimulation?
What the patient can tolerate
300mT/m
300W/kg
1 degree Celsius
What the patient can tolerate
Which of the following will produce the greatest possibility of peripheral nerve stimulation when we change the following, but not the slew rate?
Moving from a large image matrix (384×384) to a small image matrix (160×160)
Changing your slice thickness from 2mm to 7mm
Moving from a small FOV (120mm) to a large FOV (350mm)
Moving from a small image matrix (320×320) to a large image matrix (512×512)
Moving from a small image matrix (320×320) to a large image matrix (512×512)
Where will peripheral nerve stimulation be felt with the most intensity?
At isocenter
Further away from isocenter in the gantry
At the level of the table when it is advanced
Outside the gantry near the 5 gauss line
Further away from isocenter in the gantry
Which of the following is true if we increase the field of view from 200mm to 400mm?
We use a weak time-varying gradient magnetic field
We reduce patient heating
We increase the patient heating
We use a stronger time-varying gradient magnetic field
We use a weak time-varying gradient magnetic field
Which of the following concerns can be caused by the time-varying gradient magnetic field with a lead in the heart?
Muscle fatigue
Anaphylaxis
Arrhythmia
All of the choices
Arrhythmia
Which of the following is measured in milliseconds?
Spatial gradient
The rise time
The slew rate
Maximum gradient peak
The rise time
Which of the following pulse sequences will produce the greatest chance for peripheral nerve stimulation?
Conventional spin echo
Fast spin echo
Gradient echo
EPI
EPI
Which of the following will produce a minimal chance of peripheral nerve stimulation when using the same slew rate?
Going from a small image matrix (256×256) to a large image matrix (512×512)
Going from a large FOV (300 mm) to a small FOV (200 mm)
Going from a thick slice (5 mm) to a thin slice (1 mm)
Going from a large image matrix (512 x 512) to a small image matrix (320×320)
Going from a large image matrix (512 x 512) to a small image matrix (320×320)
Do not expose implant to more than 80% the maximum threshold of the gradient coils, means:
That we must stay in normal operation mode.
That we must stay in first-level mode
That we must stay in second-level mode
That we must stay in normal operation mode.
The slew rate influences which of the following?
The amount of induced stimulation in our patient
The amount of heating in our patient
The rotational forces
The translational forces
The amount of induced stimulation in our patient
Which of the following bioeffects are associated with the time-varying gradient magnetic field? Select all that apply.
Significant heating
Magnetophosphenes
Magnetohydrodynamic effect
Peripheral nerve stimulation
Magnetophosphenes
Peripheral nerve stimulation
Which of the following is measured in mT/m?
The rise time
Maximum gradient peak
The slew rate
Spatial gradient
Maximum gradient peak
Which of the following is measured in T/m/s?
The slew rate
Maximum gradient peak
The rise time
Spatial gradient
The slew rate
1.5T and 3T MR units typically have a maximum gradient peak of what?
10-20 mT/m
0-20 mT/m
20-35 mT/m
30-45 mT/m
30-45 mT/m