MRI Safety 1 Flashcards by Elad Nevo

The Insulated container used to transfer a cryogen is called a:

a. Flask
b. cryogenerator
c. dewar
d. none of the above

c. Dewar

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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

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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

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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

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At what lever of O₂in the air should the oxygen monitor first sound alarm

a. 39%
b. 29%
c. 19%
d. 9%

c. 19%

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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

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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

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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

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The most common reason for a manual quence is

a. projectile
b. ice block
c. vacuum leak
d. fire

d. fire

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Which pulse sequence would be of greatest safety concern regarding peripheral nerve stimulation

a. CSE
b. FSE
c. GRE
d. EPI

d. EPI

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Patients with tattoos should avoid MRI

a. true
b. false

b. false

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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

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Superconducting magnet coils are formed from which alloy

a. copper
b. titanium
c. niobium-titanium
d. none of the above

c. niobium - titanium

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Nitrogen liquefies below what temperature

a. 4.17K
b. 9.5K
c. 77.3 K
d. 273.16 K

c. 77.3 K

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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 I₀being 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

Prolonged inhalation of helium may lead to which of the following I. lowered voice pitch II. asphyxiation III. frostbite a. I only b. I and III only c. II and III only d. I II and III

c. II and III only

The standard dose of gadolinium agents is a. .1 mmol/g b. .1 mmol/kg c. .2 mmol/g d. .2 mmol/kg

b. .1 mmol/kg

After receiving an administration of an IV MRI contrast agent, it is recommended that women not breast feed for a. 1 hour b. 2 hours c. 1 day d. 2 days

d. 2 days

What type of patient does not require physiologic monitoring a. sedated b. anesthesized c. uncommunicable d. none of the above

d. none of the above

Sound is a(n) a. electromagnetic wave b. mechanical pressure wave c. a and b d. none of the above

b. mechanical pressure wave

The process of bringing up the static magnetic field to strength is called a. quenching b. venting c. ramping d. boiling off

c. ramping

If helium is vented into the MR scan room, what could occur a. strong odor b. displacement of air c. a and b d. none of the above

b. displacement of air

A large metallic object drawn into the MRI magnet system can instigate a quench a. true b. false

a. true

The sound level of an EPI sequence used in clinical MRI would probably be nearest a. 10dB b. 50dB c. 100dB d. 500dB

c. 100dB

Static magnetic fields existing outside of the magnet bore are called a. extraneous RF b. gradient moment nulling c. gradient fields d. fringe fields

d. fringe fields

Which of the following FDA limits for average whole body SAR is correct a. 3 W/kg b. 4 W/kg c. 3 kW/g d. 4 kW/g

b. 4 W/kg

FDA requirements state that MRI facilities should clearly indicate what level of field a. .5G b. 5G c. 5T d. b and c

b. 5G

Fringe magnetic fields can be reduced by a. shimming b. shielding c. a and b d. none of the above

b. shielding

For a superconducting MRI scanner, which magnetic field is always on a. RF field b. static field c. gradient field d. b and c

b. static field

Most claustrophobic MRI patients undergo a. relaxation techniques b. desensitization c. hypnosis d. pharmacological sedation

d. pharmacological sedation

Gadolinium is a a. metal b. ligand c. a and b d. none of the above

a. metal

Pregnant MRI healthcare workers may not enter the MRI scan room a. true b. false

b. false

Earplugs are a form of a. active noise control b. passive noise control c. a and b d. none of the above

b. passive noise control

Concerning the possibility of pregnant MRI workers entering the scan room, which of the following is probably inadvisable from a precautionary standpoint a. participating in interventional procedures in scan room b. monitoring patients while in scan room c. a and b d. none of the above

c. a and b

The ambient temperature in the MRI scan room should be closest to a. 0 C b. 10 C c. 20 C d. 30 C

c. 20 C

Which of the following exams utilize ionizing radiation I. radiography II. CT III. MRI a. I only b. I and II only c. III only d. I II and III

b. I and II only

The FDA label approved injection rate for gadolinium IV agents is a. 10 ml/sec b. 10 ml/ 5 sec c. 10ml/ 15 sec d. 10ml/ 50 sec

c. 10 ml/ 15 sec

Which of the following has a ferromagnetic componenet a. aluminium b. stainles steel c. titanium d. a and b

b. stainless steel

A patient presenting with a history of hemodialysis is most likely to have which condition a. aortic aneurysm b. aortic dissection c. pulmonary embolism d. renal insufficiency

d. renal insufficiency

For MRI breast exams, which of the following can affect the pattern of contrast media enhancement a. date of last menstrual period b. taking of oral contraceptives c. a and b d. none of the above

c. a and b

What kind of screening procedure is required before an individual can enter the MRI scan room a. written b. verbal c. a or b d. a and b

d. a and b

The unit dB for the sound intensity is called a. decabel b. decibel c. delibel d. dumbel

b. decibel

Hearing damage due to excessive sound levels occurs in the a. EAM b. middle ear c. inner ear d. none of the above

c. inner ear

Faraday's law states that ____ induce a voltage in a conductor a. static magnetic fields b. time varying magnetic fields c. a and b d. none of the above

b. time varying fields

For ethical reasons, most studies reporting potential bioeffects of static magnetic fields have been conducted on a. phantoms b. human beings c. mice, rats, rabbits, etc.. d. none of the above

c. mice, rats, rabbits etc..

The volume ratio of helium gas compared to the liquid state is closest to a. 1:1 b. 10:1 c. 1,000:1 d. 1,000,000:1

c. 1,000:1

New fluotropic systems are utilized in MRI to measure patient a. respiratory rate b. heart rate c. temperature d. a and b

c. temperature

Normal core body temp is a. 36 C b. 37 C c. 38 C d. 39 C

b. 37 C

Under normal physiological conditions, MRI gadolinium contrast media will cross a. blood brain barrier b. placental barrier c. a and b d. none of the above

b. placental barrier

Which of the following items are contraindicated for MRI a. ICC b. ICD c. ICE d. none of the above

b. ICD

The absolute zero of temperature is equivalent to a. 0 K b. -273.16 C c. -459.69 F d. all of the above

d. all of the above

During an MRI procedure which individuals in the scan room should use sound protection a. patient b. family member c. technologist d. all of the above

d. all of the above

Active Noise Control utilizes the fact that noise is a. low frequency b. high frequency c. a wave d. none of the above

c. a wave

Helium liquefies below what temperature a. 4.17K b. 9.5K c. 77.3K d. 273.16K

a. 4.17K

A research study of the spontaneous abortion rate in pregnant MRI technologists found that a. the rate was the same as the general population b. the rate was 30% higher than the general population c. the rate was 30% lower than the general population d. none of the above

a. the rate wasthe same as the general population

For the following coordinate choices, where is dB/dt the smallest a. X=0,Y=0,Z=0 b. X = 10cm, Y = 0, Z = 0 c. X = 0, Y = 10 cm, Z = 0 d. X = 10cm, Y = 10 cm, Z = 0

a. X=0,Y=0,Z=0

The most common pulse sequence for fetal imaging is a. Fast GRE b. EPI c. CSE d. SSFSE

d. SSFSE

Which of the following does not contribute to patient distress in the MRI environment a. psychiatric illness b. the underlying medical problem c. the nature of the MRI physical environmen d. none of the above

d. none of the above

A 4.0T static magnetic field is equivalent to a field strength of a. 400 G b. 4,000 G c. 40,000 G d. 400,000 G

c. 40,000 G

Anaphylactoid patient reactions are impossible with MRI contrast agents a. true b. false

b. false

Which of the following described superparamagnetic iron oxide MRI contrast agents I. colloids II. negative agents III. take up by Kupffer cells a. I and II only b. II and III only c. III only d. I II and III

d. I II and III

The best diagnosis of fetal anomalies in pregnant patients is provided by a. sonography b. CT c. MRI d. radiography

c. MRI

Typical recommendations for NPO patients are a. 2 hr clear liquids, 2 hr light meal b. 2 hr clear liquid, 6hr light meal c. 6 hr clear liquid, 2 hr light meal d. 6 hr clear liquid, 6 hr light meal

b. 2 hr clear liquid, 6hr light meal

SAR means a. specific attenuation ratio b. specific attenuation rate c. specific absorption ratio d. specific absorption rate

d. specific absorption rate

Use of MRI contrast media during pregnancy requires I. informed consent II. written, informed consent III. Physician's order a. I only b. II only c. I and III only d. II and III only

d. II and III only

In MRI screening, the standard test for metallic foreign bodies is a. film/screen radiography b. digital radiography c. CT scan d. a or c

a. film/screen radiography

The most common procedure performed in dedicated extremity MRI systems is a. abdomen b. shoulder c. wrist d. Knee

d. Knee

Adolescants should be screened for MRI when they are a. alone b. with parent c. a and b d. none of the above

c. a and b

The best MRI safety measure is a. plain film radiography b. patient education c. verbal interview d. physician referral

b. patient education

Patient sedatives issues are resolved by a. screener b. technologist c. radiologist d. all of the above

c. radiologist

Which of the MRI procedures below has teh highest rate of non-compliance a. breast b. pelvis c. cervical d. all of the above

a. breast

The best way to avoid patient burns with monitoring equipment is to use a. hard wire cables b. co axial cable c. fiber optic cables d. none of the above

c. fiber optic cables

Which method would generally be the best to allay patient anxiety a. explain procedure to patient before entering scan room b. explain procedure to patient while in scan room c. explain procedure over intercom d. do not explain procedure

a. explain procedure to patient before entering scan room

The standard practice for monitoring sedated or anethesized patients is a. capnometer b. ventilator c. pulse oximetry d. none fo the above

c. pulse oximetry

A previous MRI scan without safety incident does not guarantee the safety of a subsequent MRI exam a. true b. false

a. true