MRI Safety 1 Flashcards
The Insulated container used to transfer a cryogen is called a:
a. Flask
b. cryogenerator
c. dewar
d. none of the above
c. Dewar
With regard to gadolinium based contrast agents, the term NSF indicates
a. neurologic systemic fibrosis
b. nephrogenic systemic fibrosis
c. a and b
d. none of the above
b. nephogenic systemic fibrosis
The risk of hearing damage increases with all the factors below except
a. noise level
b. noise duration
c. age of adult
d. environment temperature
d. environment temperature
Why is it necessary to monitor the ECG after an MRI procedure
a. to establish a baseline trace
b. to verify that the ECG unit is functioning properly
c. to insure that hte patient is not undergoing myocardial infarction
d. none of the above
c. to insure that the patient is not undergoing myocaridal infarction
At what lever of O2 in the air should the oxygen monitor first sound alarm
a. 39%
b. 29%
c. 19%
d. 9%
c. 19%
Which of the following MRI monitoring device types are unaffected by the MRI environment
I. LCD
II. CRT
III. Fiber Optic
a. I only
b. III only
c. I and III only
d. II and III only
c. I and III only
Which of the following describe chelated gadolinium based intravenous MRI contrast agents
I. negative agents
II. T1 shortening agents
III. nephrotoxic
a. I only
b. II only
c. I and II only
d. I II and III only
b. II only
the biologic half life of chelated gadolinium IV contrast agents is approximately
a. 1.5 hours
b. 1.5 days
c. 5 hours
d. 5 days
a. 1.5 hours
The most common reason for a manual quence is
a. projectile
b. ice block
c. vacuum leak
d. fire
d. fire
In 2003, the FDA designated magnetic field strengths up to ___ as a non significant risk for adult MRI patients
a. 2.0T
b. 4.0T
c. 8.0T
d. none of the above
c. 8.0 T
If monitoring device adversly impacts the quality of the MRI image it cannot be
a. MR safe
b. MR compatible
c. a and b
d. none of the above
b. MR compatible
Compared to patients in 2.0T MR systems, patients in 4.0 MR systems report increased sensations of
a. nausea
b. vertigo
c. metallic taste
d. all of the above
d. all of the above
In order to avoid any negative sensations in 4.0T MR systems, it is best to have the patient do what in the MR scan room
a. close eyes
b. take deep breaths
c. move slowly
d. all of the above
c. move slowly
Which of the following is outside the MRI technologist scope of practice
a. adminestering contrast agents
b. adminestering sedatives
c. written screening
d. b and c
b. adminestering sedatives
magnetophosphenes are believed to result from
a. stimulation of optic nerve
b. currents induced by rapidly changing gradient magnet fields
c. eye of head movements in large static magnetic fields
d. all of the above
d. all of the above
Acoustic noise in MRI is due principally to the operation of
a. RF field system
b. Gradient field system
c. static field system
d. none of the above
b. Gradient field system
the two major MRI safety issues involving gradient magnetic fields include which of the following
I. power deposition
II. peripheral nerve stimulation
III. acoustic noise
a. I and II
b. I and III
c. II and III
d. none of the above
c. II and III
FDA rules require that
a. dB/dt < 6mT/s
b. dB/dt < 60mT/s
c. dB/dt < 6 T/s
d. dB/dt < 60 T/s
c. dB/dt < 6 T/s
According to the American College of Radiology, the standard of care is to inform pregnant women that
a. clinical MRI does not produce harmful bioeffects during pregnancy
b. there is no evidence that clinical MRI produces harmful bioeffects during pregnancy
c. clinical MRI should not be performed during pregnancy
d. a and b
b. there is no evidence that clinical MRI produces harmful bioeffects during pregnancy
Which pulse sequence would be of greatest safety concern regarding peripheral nerve stimulation
a. CSE
b. FSE
c. GRE
d. EPI
d. EPI
Patients with tattoos should avoid MRI
a. true
b. false
b. false
Where and how do cables and wires exit the magnet bore
a. center of table, crossed
b. edge of table, crossed
c. cnenter of table, uncrossed
d. edge of table, uncrossed
c. center of table, uncrossed
Superconducting magnet coils are formed from which alloy
a. copper
b. titanium
c. niobium-titanium
d. none of the above
c. niobium - titanium
Nitrogen liquefies below what temperature
a. 4.17K
b. 9.5K
c. 77.3 K
d. 273.16 K
c. 77.3 K
Which of the following are advantages of superconducting MR scanners
I. low power consumption
II. low capital cost
III. low field homogeneity
a. I only
b. I and II
c. II and III
d. I II and III
a. I only
A sudden loss of superconductivity is called a
a. ramp up
b. ramp down
c. quench
d. boil off
c. quench
RF effects in patients are believed to be mainly due to
a. peripheral nerve stimulation
b. gastrointestinal
c. tissue heating
d. a and c
d. tissue heating
Which of the following conditions can alter a patients ability to dissipate heat
I. medications
II. age
III. hypertension
a. I only
b. I and III only
c. II adn III only
d. I II and III
d. I II and III
If the release of cryogen prevents opening the MR scan room doom, the proper procedure is to
a. instigate a quench
b. breakdown scan room door
c. break scan room window
d. a and c
c. break scan room window
which of the following FDA limits for SAR in the extremities is correct
a. 8 W/kg
b. 12 W/kg
c. 8 kW/g
d. 12 kW/g
b. 12 W/kg
the FDA requires that core body temperature increases during MRI be no greater than
a. 1 C
b. 1 F
c. 40 C
d. 40 F
a. 1 C
Which pulse sequences would be of concern for RF power depositions
I. gradient echo
II. fast spin echo
III. magnetization transfer
a. I only
b. I and II only
c. II and III
d. I II and III
d. I II and III
Ear plugs can reduce the sound intensity level experienced by a patient. this is an example of
a. passive noise control
b. active noise control
c. reactive noise control
d. none of the above
a. passive noise control
If I is the sound intensity with I0 being the reference sound level (threshold of hearing), then the equation for the sound intensity level ß is
a. ß = log(I/I0)
b. ß = log (I0/I)
c. ß = 10 log(I/I0)
d. ß = 10 log (I0/I)
c. ß = 10 log(I/I0)
Which of the following are contraindications to chelated gadolinium contrast agents
I. pregnancy
II. sickle cell anemia
III. allergyn to iodine based x - ray agent
a. I only
b. I and II only
c. III only
d. none of the above
d. none of the above
the two most temperature sensitive organs in human being are which of the following
I. testes
II. ovaries
III. eyes
a. I and II
b. I and III
c. II and III
d. none of the above
b. I and III
What kind of response is characteristic for a claustrophobic MRI patient
a. immediate
b. delayed
c. transitory
d. none of the above
a. immediate
The maximum FDA label approved dose of Magnevist for a 95lb patient is
a. 4.3ml
b. 8.6ml
c. 9.5ml
d. 20 ml
b. 8..6ml
Breathing in a pure environment of which gas is most hazardous for humans
a. helium
b. nitrogen
c. oxygen
d. air
b. nitrogen
Which MRI studies would be likely to be performed during pregnancy
I. suspected brain tumor
II. routine Knee
III. AVM
a. I only
b. II only
c. I and III only
d. I II and III
c. I and III only