Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

001 MRI > EXAM #10 — PHYSICS UNIT 03 > Flashcards

EXAM #10 — PHYSICS UNIT 03 Flashcards

1
Q

define the following term:

specific absorption rate (SAR).

A

a measure of energy (RF) dissipation in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define the following term:

time varying magnetic fields.

A

magnetic fields whose strength varies over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define the following term:

exclusion zone.

A

the area around the MRI magnet where the field strength is 5 Gauss or stronger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

identify the 3 types of electromagnetic fields that are used in MRI.

A

static field, gradient fields, RF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

identify the maximum static magnetic field strength allowed by the FDA for clinical imaging of patients over 1 month old.

A

8 Tesla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

discuss the risk of irreversible biological effects of static magnetic field strengths less than 2T.

A

no known risk of irreversible biological effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

identify the primary safety hazard associated with static magnetic fields.

A

interaction with metallic objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

identify the primary safety hazard associated with gradient magnetic fields.

A

induced electrical currents in conductors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

identify 3 reversible, temporary biological effects associated with very rapidly
switching gradient magnetic fields.

A

visual flashes, skin sensation, and muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

identify the unit of measure of specific absorption rate (SAR).

A

Watts/kilogram (Wlkg)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

identify the maximum SAR values for:

a. whole-body imaging in the US. ___ W/kg
b. head imaging in the US. ___ W/kg

A

identify the maximum SAR values for:

a. whole-body imaging in the US. 4.0 W/kg
b. head imaging in the US. 3.0 W/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

discuss the primary potential biological response to RF in the MRI environment.

A

tissue heating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

discuss the primary hazard associated with RF in the MRI environment.

A

burns or fires caused by the induction of electrical currents in conductors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

state the patient information that directly affects SAR calculation.

A

weight and age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

state 4 ways in which an implanted cardiac pacemaker is dangerous in the MRI environment.

A

deflection of pacemaker generator, reed switch malfunction, pacemaker reprogramming, induction of electrical current in pacemaker leads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

identify 2 objects that are often present in an MRI site and have wires that can form conductive loops.

A

surface coils, patient monitoring equipment (EKG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

discuss 3 hazards associated with metallic implants and MR imaging.

A

deflection, heating, artifacts that can cause misdiagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

safe / unsafe / conditionally

cardiac pacemaker.

A

Unsafe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

safe / unsafe / conditionally

intracranial aneurysm clip.

A

Conditionally safe (depends on specific model)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

safe / unsafe / conditionally

intravascular filter or stent.

A

Conditionally safe (depends on time since implantation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

safe / unsafe / conditionally

vascular access port.

A

Conditionally safe (depends on specific model)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

safe / unsafe / conditionally

prosthetic heart valve.

A

Safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

safe / unsafe / conditionally

otologic implant.

A

Conditionally safe (depends on specific model)

24
Q

safe / unsafe / conditionally

ocular implant.

A

Conditionally safe (depends on specific model)

25
Q

safe / unsafe / conditionally

bullet, pellet, or shrapnel.

A

Conditionally safe ( depends on location in body)

26
Q

safe / unsafe / conditionally

surgical staples in abdomen.

A

Safe

27
Q

safe / unsafe / conditionally

halo vest, external fixation device.

A 
Conditionally safe (depends on specific
model)
28
Q

safe / unsafe / conditionally

orthopedic internal fixation.

A

Safe

29
Q

safe / unsafe / conditionally

neurostimulator.

A

Conditionally safe (depends on several factors, must rely on specific manufacturer’s guidelines)

30
Q

safe / unsafe / conditionally

bone growth stimulator.

A

Conditionally safe ( depends on several factors, must rely on specific manufacturer’s guidelines)

31
Q

safe / unsafe / conditionally

intraocular metallic foreign body.

A

Unsafe

32
Q

safe / unsafe / conditionally

internal cardiac defibrillator.

A

Unsafe

33
Q

safe / unsafe / conditionally

internal drug infusion pump.

A

Conditionally safe (depends on several factors, must rely on specific manufacturer’s guidelines)

34
Q

deflection / current / malfunction

cardiac pacemaker.

A

All

35
Q

deflection / current / malfunction

intracranial aneurysm clip.

A

Deflection

36
Q

deflection / current / malfunction

intravascular filter or stent.

A

Deflection

37
Q

deflection / current / malfunction

vascular access port.

A

Heating

38
Q

deflection / current / malfunction

prosthetic heart valve.

A

Deflection, malfunction

39
Q

deflection / current / malfunction

otologic implant.

A

Deflection

40
Q

deflection / current / malfunction

ocular implant.

A

Deflection

41
Q

deflection / current / malfunction

bullet, pellet, or shrapnel.

A

Deflection, heating

42
Q

deflection / current / malfunction

surgical staples in abdomen.

A

Deflection

43
Q

deflection / current / malfunction

halo vest, external fixation device.

A

Deflection

44
Q

deflection / current / malfunction

orthopedic internal fixation.

A

Deflection

45
Q

deflection / current / malfunction

neurostimulator.

A

All

46
Q

deflection / current / malfunction

bone growth stimulator.

A

All

47
Q

deflection / current / malfunction

intraocular metallic foreign body.

A

Deflection

48
Q

deflection / current / malfunction

internal cardiac defibrillator.

A

All

49
Q

deflection / current / malfunction

internal drug infusion pump.

A

Deflection, malfunction

50
Q

state the fringe field strength that defines the exclusion zone.

A

5 Gauss

51
Q

identify the most reliable source for MRl safety information on a specific implant.

A

implant manufacturer

52
Q

discuss the primary hazard associated with a superconducting magnet quench.

A

asphyxiation by gaseous helium in the magnet room

53
Q

discuss 2 safety issues related to the acoustic noise generated by MRl systems.

A

difficult patient/technologist communication, hearing loss

54
Q

discuss the US FDA guidelines for scanning pregnant patients.

A

the scanning of pregnant patients is neither recommended nor prohibited

55
Q

discuss the Society of Magnetic Resonance Imaging (SMRl) Safety Committee’s recommendation for scanning pregnant patients.

A

the risk of injury to the fetus should be weighed with the potential benefit to the mother and fetus

001 MRI (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions