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Flashcards in MRI Safety 1 Deck (100)
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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



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