Week 5 Quiz

Question 1

The MR signal is produced by magnetization _________________.

Select one:
a. in the longitudinal direction
b. decaying
c. in the transverse plane
d. out of phase

Answer 1

in the transverse plane

Question 2

What is the normal range of lab values for creatinine:

A. 0.6-1.2 mg/dL
B. 7-20 mg/dL
C. >60 mL/min
D. <60mL/min

Answer 2

0.6-1.2 mg/dL

Question 3

ACR guidelines recommend a 4-zone system for MR suites. Zone 1 is best describe with which description.?

Select one:

A. Area has restricted access and contains the MR scanner, anyone who enters this Zone must be directly supervised by trained MR personnel.

B. Area is freely accessible to the public, contains areas such as the reception desk and lobby.

C. Area is the buffer between freely accessible and restricted zones, this is the Zone where screening occurs and contains areas such as dressing rooms.

D. Area has restricted access and contains the scanner control room, only screened individuals are allowed into this area.

Answer 3

Area is freely accessible to the public, contains areas such as the reception desk and lobby

Question 4

There are a total of ___ tarsal bones.

a. 4
b. 5
c. 7
d. 8

Answer 4

7

Question 5

If a phase resolution of 256 is desired, then the TR must be repeated ___________ times (for 1 NSA).

Select one:
a. 256
b. 512
c. twice
d. 192

Answer 5

256

Question 6

The gradient magnetic fields are:

Select one:
a. controlled by RF pulses
b. always on
c. used for contrast control
d. superimposed over the main magnetic field

Answer 6

superimposed over the main magnetic field

Question 7

In a gradient echo sequence, reducing the flip angle while holding the TR constant reduces ______________.

Select one:
a. T2* contrast weighting
b. spin density contrast weighting
c. saturation
d. scan time
e. all of the above

Answer 7

saturation

Question 8

Which sequence of RF pulses accurately depicts a CSE sequence?

Select one:
a. 90 - 180 - 90
b.180 - 90 - 180
c. 90 - 90 - 90
d. 90 - 45 - 45

Answer 8

90-180-90

Question 9

Fourier transform will be applied to:

Select one:
a. free induction decay
b. RF signal
c. post-processed image data
d. data in k-space

Answer 9

data in k-space

Question 10

What parameter affects voxel volume?

Select one:
a. slice thickness
b. TI
c. FID
d. TR

Answer 10

slice thickness

Question 11

A gradient echo pulse sequence uses a _________________ to produce the echo.

Select one:
a. gradient magnetic field
b. ionizing radiation pulse
c. acoustic resonance trigger
d. electrical switching device

Answer 11

gradient magnetic field

Question 12

The individual hydrogen protons aligned in the parallel direction, in excess of the number aligned in the antiparallel direction, produce a _____________ vector parallel to the main magnetic field.

Select one:
a. net magnetization
b. varying
c. rotating
d. oscillating

Answer 12

net magnetization

Question 13

The B1 magnetic field is oriented _______________ to the static magnetic field.

Select one:
a. perpendicular
b. parallel
c. 180 degrees
d. at a 45-degree angle

Answer 13

perpendicular

Question 14

ACR guidelines recommend a 4-zone system for MR suites. Zone 3 is best describe with which description.?

Select one:

A. Area has restricted access and contains the MR scanner, anyone who enters this Zone must be directly supervised by trained MR personnel

B. Area is freely accessible to the public, contains areas such as the reception desk and lobby

C. Area is the buffer between freely accessible and restricted zones, this is the Zone where screening occurs and contains areas such as dressing rooms

D. Area has restricted access and contains the scanner control room, only screened individuals are allowed into this are

Answer 14

Area has restricted access and contains the scanner control room, only screened individuals are allowed into this area.

Question 15

_____________ describes the condition reached within a few seconds of hydrogen being placed in a magnetic field.

Select one:
a. FID
b. Equilibrium
c. Resonance
d. Phase coherence

Answer 15

Equilibrium

Question 16

SNR is a ratio of MR signal to ___________.

Select one:
a. noise
b. TR
c. scan time
d. TE

Answer 16

noise

Question 17

Aliasing is another name for:

Select one:
a. fold over
b. wrap around
c. ghosting
d. a & b
e. all of these

Answer 17

A & B

Question 18

Aliasing occurs when:

Select one:
a. the FOV is too large
b. the FOV is too small
c. the slice thickness is greater than 3mm
d. when gating is not used

Answer 18

the FOV is too small

Question 19

The hydrogen proton has been used for MR imaging because:

Select one:
a. it is the most abundant element in the body
b. it possesses a magnetic moment
c. it precesses at a frequency which is in a safe range with currently available magnets
d. all of these

Answer 19

All of these

Question 20

Precession refers to:

Select one:
a. the frequency of the RF pulse used to excite the proton
b. the orientation of the imaging plane within the magnetic field
c. the “wobble” of the axis of the proton as it spins in the magnetic field
d. the process by which the proton loses energy after excitation by the RF pulse

Answer 20

the “wobble” of the axis of the proton as it spins in the magnetic field

Question 21

Which of the following RF flip angles maximizes the amount of transverse magnetization?

Select one:
a. 45°
b. 120°
c. 180°
d. 90°

Answer 21

90 degree

Question 22

Which of the following is not a requirement for magnetic resonance imaging?

Select one:
a. a strong magnetic field
b. RF energy
c. atomic nuclei with unpaired nucleons
d. ionizing radiation

Answer 22

ionizing radiation

Question 23

With conventional spin echo a single “line” of k-space is filled during each ________________.

Select one:
a.TR
b. excitation
c. TE
d. frequency encoding

Answer 23

TR

Question 24

The formula that describes the relationship between the static magnetic field and the precessional frequency of the hydrogen protons is the ___________.

Select one:
a. Helmholtz relationship
b. Bloch equation
c. Larmor equation
d. Nyquist theorem

Answer 24

Larmor equation

Question 25

The RF energy used in MRI is classified as _______________. Select one: a. a magnetic beam b. investigational waveform c. electromagnetic radiation d. non-radiation energy

Answer 25

electromagnetic radiation

Question 26

If the TR of a gradient echo sequence is less than the T1 and T2 time of tissue, a condition known as ______________ will be achieved. Select one: a. echo readout b. steady state c. spin dephasing d. spin saturation

Answer 26

steady state

Question 27

Which of the following parameters affects image contrast? Select one: a. Matrix size b. FOV c. NEX d. TR

Answer 27

TR

Question 28

To calculate the precessional frequency, the strength of the static magnetic field is multiplied by a constant known as ______________. Select one: a. the gyromagnetic ratio b. linear attenuation coefficient c. alpha-1 d. tau

Answer 28

the gyromagnetic ratio

Question 29

If a phase resolution of _______ is desired, then the TR must be repeated 512 times (for 1 NSA). Select one: a. twice b. 256 c. 512 d. 192

Answer 29

512

Question 30

The U.S. Food and Drug Administration recommends that patients not be subjected to sound levels greater that _____ dB without hearing protection. a. 50 b. 85 c. 99 d. 130

Answer 30

99

Question 31

If a patient has a history of metal shavings in their eye(s), the accepted standard for screening is _______________. Select one: a. CT scan b. nothing, the patient is not to be scanned with MRI c. physical examination d. plain film x-ray of the orbits

Answer 31

plain fil x-ray of the orbits

Question 32

With conventional spin echo a single "line" of k-space is filled during each ________________. Select one: a. TR b. frequency encoding c. excitation d. TE

Answer 32

TR

Question 33

The SAR limit set by the FDA for the head is: a. 3 W/kg averaged over 10 minutes b. 4 W/kg averaged over 15 minutes c. 8 W/kg averaged over 5 minutes d. 12 W/kg averaged over 5 minutes

Answer 33

3 W/kg averaged over 10 minutes

Question 34

A magnetic field strength of 1 Tesla is equivalent to ____________ Gauss. Select one: a. 10,000 b. 1,000 c. 1.0 d. 15,000

Answer 34

10,000

Question 35

A surface coil wire cannot cause an injury to the patient if it is not frayed. Select one: True False

Answer 35

False

Question 36

A gradient echo pulse sequence uses a _________________ to produce the echo. Select one: a. gradient magnetic field b. ionizing radiation pulse c. acoustic resonance trigger d. electrical switching device

Answer 36

gradient magnetic field

Question 37

_________ is defined as threatening to harm an individual. a. Coercion b. Negligence c. Assault d. Battery

Answer 37

Assault

Question 38

The strength of magnetic fringe fields is measured in: Select one: a. Gauss b. Watts c. Tesla d. SAR

Answer 38

Gauss

Question 39

The static magnetic field strength of MR systems is measured in units of: Select one: a. SAR b. Watts c. Gauss d. Tesla

Answer 39

Tesla

Question 40

Malpractice is defined as: A. A legal or civil wrong committed by one person against the person or property of another B. An obligation not to inflict harm intentionally C. Professional misconduct, improper discharge of professional duties, or a failure to meet the standard of care by a professional that results in harm to another D. A failure to exercise the appropriate/reasonable level of care expected to be exercised by professionals in a given circumstance

Answer 40

Professional misconduct, improper discharge of professional duties, or a failure to meet the standard of care by a professional that results in harm to another

Question 41

What is the normal range of lab values for BUN: A. 0.6-1.2 mg/dL B. 7-20 mg/dL C. >60 mL/min D. <60mL/min

Answer 41

7-20 mg/dL

Question 42

Cables from ECG leads and RF coils must be: a. placed straight through the bore of the magnet, not coiled b. laid into neat loops at the patient's feet c. laid along the patient's right arm, neatly braided d. no particular placement is required as long as the cables are plugged in

Answer 42

placed straight through the bore of the magnet, not coiled

Question 43

Gradient magnetic fields are used to ______________. Select one: a. control the image contrast b. spatially encode signal c. improve the SNR d. transmit the RF pulse

Answer 43

spatially encode signal

Question 44

What is the normal range of lab values for eGFR: A. 0.6-1.2 mg/dL B. 7-20 mg/dL C. >60 mL/min D. <60mL/min

Answer 44

>60 mL/min

Question 45

Presaturation pulses are used to ________________. Select one: a. turn flowing blood bright b. reduce scan time c. improve spatial resolution d. reduce flow artifacts

Answer 45

reduce flow artifacts