Brainscape's Knowledge GenomeTM

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


See full index

MRI > Test 2 > Flashcards

Test 2 Flashcards

1
Q

What is the readout gradient is also known as?
a. RF encoding gradient
b. Frequency encoding gradient
c. Phase encoding gradient
d. Slice select gradient

A

B

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

What is the center of the bore in all planes is known as?
a. Claustrocenter
b. Hypercenter
c. Isocenter
d. Hypocenter

A

C

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

When does the frequency encoding gradient turn on in a CSE pulse sequence?
a. Between the 90º and 180º pulses
b. During the 90º and 180º pulses
c. During the FID
d. During the spin echo

A

D

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

What is the range of frequencies sampled during the read out gradient (sampling window) known as?
a. Spatial encoding
b. Spin echo
c. Transmit bandwidth
d. Receive bandwidth

A

D

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

In general, what do small FOVs and thin slices require?
a. Steep gradients
b. Short TRs
c. Wide bandwidths
d. Long RF pulses

A

A

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

During the scan, where is data stored?
a. Hard drive
b. k-Space
c. Chest of drawers
d. Spin echo

A

B

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

What is the mathematical process that converts frequency amplitudes from the time domain to the frequency domain in order to locate them spatially?
a. FID
b. Fast Fourier Transform
c. Readout gradient
d. k-Space

A

B

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

What determines which line of k-space get filled?
a. k-Space gradient
b. Slice select gradient
c. Readout gradient
d. Phase encoding gradient

A

D

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

Data in the outer lines of k-space contribute to ________ information.
a. Signal and contrast
b. Distal pixels
c. Resolution
d. T1 or T2

A

C

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

A single data point of k space contains information from the entire slice.
True
False

A

T

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

FLAIR is a fast IR sequence that nulls signal from what tissue?
a. White matter
b. Water/CSF
c. Fat
d. Muscle

A

B

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

In order to null the signal from a tissue using an IR sequence, the TI must be what?
a. at the larmor frequency
b. 0.69 times the T1 time of the tissue
c. 0.69 times the T2 time of the tissue
d. In steady state

A

B

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

What pulse sequence is a 90º pulse followed by a 180º pulse?
a. FIESTA
b. SSFSE
c. CSE
d. FSE

A

C

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

In a Fast/Turbo spin echo sequence, data from echoes farther away from the effective TE will be placed where?
a. In a shallow readout gradient
b. In noise
c. In the central lines of K space
d. In the outer lines of K space

A

D

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

A sequence that uses a reverse flip angle at the end of the echo train to restore residual transverse magnetization into the longitudinal plane is known as what?
a. Single Shot Fast Spin Echo/SSFSE/HASTE
b. FIESTA/Balanced gradient echo
c. Incoherent Gradient Echo/SPGR
d. DRIVE/FR-FSE/Driven equilibrium Fourier transform

A

D

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

Which inversion recovery sequence has the shortest TI?
a. FSE
b. FLAIR
c. STIR
d. SSFSE

A

C

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

What is TI?
a. Time from 180º inversion pulse to the 90º excitation pulse
b. Time from the 90º excitation pulse to the 180º rephasing pulse
c. Time from 90º inversion pulse to the 90º excitation pulse
d. Time from 90º excitation pulse to the 180º inversion pulse

A

A

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

What is Tau?
a. Time from 180º inversion pulse to the 90º excitation pulse
b. Time from the 90º excitation pulse to the 180º rephasing pulse
c. Time from 90º inversion pulse to the 90º excitation pulse
d. Time from 90º excitation pulse to the 180º inversion pulse

A

B

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

What is TE?
a. Time from 180º inversion pulse to the 90º excitation pulse
b. Time from the 90º excitation pulse to the 180º rephasing pulse
c. Time from 90º inversion pulse to the 90º excitation pulse
d. Time from 90º excitation pulse to the peak of echo

A

D

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

Increasing ETL will result in

    I. Increased T1 weighting

    II. Reduced scan time

    III. Increased heating

a. II and III
b. I and II
c. I and III
d. I, II, and III

A

A

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

The technologist selects a TR of 600ms and a TE of 30ms for a CSE sequence. What weighting should they expect?
a. T1
b. T2
c. Diffusion
d. PD

A

A

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

How does a CSE pulse sequence compensate for T2*?
a. Long TR
b. Two rephasing pulses
c. Short TR
d. 180º rephasing pulse

A

D

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

What pulse sequence acquires all lines of k-space in one TR using FSE in combination with partial averaging?
a. CSE/FSE
b. SSFSE/HASTE
c. FRFSE/DRIVE
d. STIR/FLAIR

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What changes during every 180° rephasing echo in a Fast/Turbo spin echo?
a. Phase encoding gradient
b. Effective TE
c. Center frequency
d. Phase direction

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What occurs when a gradient is applied to B0?
a. The precessional frequencies of H increases at one end and decreases at the other
b. T2 weighting increases
c. T2 weighting decreases
d. Resonance occurs as long as it is at the Larmor frequency

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

GRE pulse sequences have more T2* than SE.
True
False

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

A pulse sequence with a TR of 50ms, a TE of 5ms, and a flip angle of 70 would result in what weighting?
PD weighting
T2* weighting
T2 weighting
T1 weighting

A

T1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

In general, GRE pulse sequences are faster than SE.
True
False

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

With a short TR, what determines the optimum flip angle to give the highest signal for a tissue?
a. Larmor equation
b. DRIVE
c. Steady State
d. Ernst angle

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What processes affect weighting in GRE?
a. All of the above
b. Flip angle
c. Steady State
d. Residual transverse magnetization

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the difference between SE and GRE

I.  GRE has a variable flip angle

II.  SE uses a 180º rephasing pulse

III. GRE uses a rephasing gradient.

a. I, II, and III
b. I and III
c. II only
d. II and III

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In incoherent gradient echo, the spoilers can be ____.
a. Only RF pulses
b. Only gradients
c. Frequency modulation
d. Gradient or RF pulses

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Decreasing pixel size will increase resolution.
True
False

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The technologist doubles the NEX. What happens to SNR?

 I.  The SNR doubles

 II. The SNR increases by √2

 III. The SNR increases by 1.4

a. II and III
b.I only
c. II only
d. II and III

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What results when slice thickness is increased?
a. Decreased SNR
b. Increased partial voluming
c. Increased chemical shift
d. Decreased coverage

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Doubling NEX will double scan time.
True
False

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Coil placement and selection is important for image quality
True
False

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What results when FOV is increased?

I. SNR increases

II. Resolution decreases

III. Coverage increases

a. II and III
b. I and III
c. I, II, and III
d. I and II

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What results when receiving bandwidth increases?

 I. Resolution increases

 II.  Minimum TE decreases

 III. SNR decreases

a. II and III
b. I, II, and III
c. III only
d. I and III

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

which of the following pulse sequences does not use a 180 refocusing RF pulse
a. spin echo
b. gradient echo
c. inversion recovery
d. fast spin echo

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does STIR stand for?
a. sequence time in relaxation
b. safe time in recovery
c. short tau inversion recovery
d. soft tune inversion RF

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

the highest signal amplitude is stored in which area of space
a. central line
b. outer line
c. top half
d. bottom half

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what do data near periphery of kspace determine?
a. contrast
b. details and resolution
c. weighting
d. slice thickness

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

a long TI required for which pulse sequence
a. STIR
b. FLAIR
c. CSE
d. DRIVE

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what determines the number of lines of k-space
a. phase matrix
b. phase encoding gradient
c. frequency matrix
d. frequency encoding gradient

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the term for the number of times data is collected with the same phase encoding gradient slope?
a. TR
b. NEX/NSA
c. frequency matrix
d. Receive bandwidth

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

adjust which parameter will have smallest effect on scan time
a. TR
b. TE
c. NEX/NSA
d. slice thickness
e. phase matrix

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

increasing what parameter will increase SNR?
a. TR
b. frequency matrix
c. TE
d. slice gap

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

increasing bandwidth will affect all of the following except:
a. decrease chemical shift
b. decrease SNR
c. decrease resolution
d. decrease minimum TE

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

decreasing slice thickness will result in all of the following except
a. decrease SNR
b. decrease coverage
c. decrease resolution
d. increase partial voluming

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what GRE pulse sequence use oscillating readout gradient to produce a train of echo
a. Fast GRE
b. EPI
c. FIESTA
d. FSE

A

B

52
Q

doubling NEX will double __
a. scan time
b. SNR
c. resolution
d. T1-W

A

A

53
Q

what is gradient amplitude

A

rate of change of mag field strength

54
Q

___ gradient amplitude will have big differences in frequencies
a. steep
b. shallow

A

A

55
Q

what is purpose of gradient axes

A

spatially locate signal along 3 gradients

56
Q

what determine slice thickness ? (2)

A

slope of gradients
range of frequencies (transmit bandwidth)

57
Q

to achieve thin slice we need ___ & ___

A

steep slope and narrow transmit bandwidth

58
Q

what is sampling window

A

amount of time the frequency encoding gradient is turned on

59
Q

sampling interval has a ____ relationship with digital sampling frequency

A

inverse

60
Q

sampling interval = ____/___

A

sampling window (s)
sampling frequency (Hz)

61
Q

incorrect frequency sampled is due to ____ which lead to artifact called ___

A

sampling frequency < Nyquist frequency
aliasing

62
Q

sampling frequency > Nyquist frequency = ____

A

more noise
time insufficient

63
Q

Receive bandwidth = ____ because both has 2 x Nyquist frequency

A

sampling frequency

64
Q

to achieve small fFOV, we need ____

A

steep frequency encoding gradient

65
Q

data in COLUMN determine ___ in ____ direction

A

size of FOV
phase

66
Q

data in ROW determine ___ in ____ direction

A

size of FOV
frequency

67
Q

duration of ____ affect minimum TE

A

sampling window

68
Q

phase FOV expressed as ____

A

% of frequency FOV

69
Q

what is frequency matrix

A

Number of pixels in frequency direction

70
Q

phase FOV is used in ____ , ____, ____

A

rectangular FOV
antialiasing
parallel imaging

71
Q

what determine frequency matrix

A

amount of time signal is sampled

72
Q

duration of sampling window affect___

A

minimum TE

73
Q

what happened when phase encoding gradient is ON

A

affect frequency of magnetic moments

74
Q

what happened when phase encoding gradient is OFF

A

frequency back to normal & phase position remains

75
Q

phase encoding gradient can be used to avoid ___

A

aliasing/wrap

76
Q

what is phase matrix

A

number of time phase encoding is turned on

77
Q

high amplitude signal = ____
which location in k-space

A

decrease resolution
central

78
Q

low amplitude signal = ___
which location in k-spce

A

increase resolution
outer

79
Q

2D scan time = _____ x ____ x_____

A

phase matrix
TR
NEX/NSA

80
Q

what is needed to create a large change in phase

A

steep slope

81
Q

small pixel = _____ phase encoding gradient

A

steep

82
Q

steep phase encoding fill ___ lines

A

outer

83
Q

shallow phase encoding fill ___ line

A

central

84
Q

we can take advantage of which fact abt k-space to reduce scan time

A

conjugate symmetry

85
Q

how pulse sequence fill k-space

A
  1. Bss pick an area of k-space
  2. phase encoding pick which line of k-space to fill
  3. frequency encoding determine how each line is filled
86
Q

what determine how each line of k-space is filled

A

frequency encoding

87
Q

what are the options to fill k-space

A
  1. partial averaging
  2. partial echo
  3. parallel imaging
    4 . single shot
    5.spiral k-space
  4. acquisition
  5. propeller/BLADE
88
Q

which options only fill half of k-space and has symmetrical top and bottom
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

1

89
Q

which option allow central line to get sample first
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

5

90
Q

which option fill many lines per TR and require special coil
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

3

91
Q

which option fill all data in k-space in a single TR with echo train
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

4

92
Q

which option has symmetrical echo that doesnt need to sample
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

2

93
Q

which option sample center every TR but has long scan time and reduce resolution
1. partial averaging
2. partial echo
3. parallel imaging
4 . single shot
5.spiral k-space
6. acquisition
7. propeller/BLADE

A

7

94
Q

FFT converts ____ from the __ domain to the ____ domain

A

frequency amplitude
time
frequency

95
Q

low amplitude signal generated ___

A

steep phase gradient + large phase change

96
Q

For nyquist theorum, what must be sampled and how many times for accuracy

A

highest frequencies
twice

97
Q

each chest = ___

A

slice in the image

98
Q

Number of chests = ___

A

Number of slice

99
Q

each drawer = ____ of k-space

A

line

100
Q

each sock = ___

A

data point

101
Q

what determine what data to put in which line

A

frequency coding gradient

102
Q

the number of data point is determined by ____

A

frequency matrix

103
Q

Thru ADC, echo received at time ___ is digitized

A

TE

104
Q

amplitude is to figure out _____

A

if a pixel is bright or dark

105
Q

frequency is to figure out ____

A

which pixel

106
Q

what is spatial encoding

A

calculate how much signal from each voxel

107
Q

SE use a ___ pulse to rephase echo

A

180

108
Q

CSE give ____ weighting

A

True T2

109
Q

pattern for CSE
1. 90-180
2. 90-180-180-180-
3. 180-90-180-180-

A

1

110
Q

pattern for FSE
1. 90-180
2. 90-180-180-180-
3. 180-90-180-180-

A

2

111
Q

FSE use ____ and has ____
while EPI use ___ & ___

A

ETL
effective TE

RF pulse and oscillating readout gradient

112
Q

DRIVE use _____ pulse

A

reverse flip pulse

113
Q

IR sequence use ____

A

TI

114
Q

pattern for IR
1. 90-180
2. 90-180-180-180-
3. 180-90-180-180-

A

3

115
Q

what pulse sequence is 90-180

A

CSE

116
Q

what pulse sequence is 180-90-180-180-

A

IR

117
Q

what pulse sequence is 90-180-180-180-

A

FSE

118
Q

STIR has ____ TI

A

short

119
Q

why STIR need a short TI

A

T1 time of fat is shorter than water

120
Q

FLAIR has ____ TI

A

long

121
Q

which pulse sequence null signal from fat
1. STIR
2. FLAIR
3. DIR
4. TIR

A

1

122
Q

which pulse sequence null signal from BLOOD
1. STIR
2. FLAIR
3. DIR
4. TIR

A

3

123
Q

which pulse sequence null signal from WATER
1. STIR
2. FLAIR
3. DIR
4. TIR

A

2

124
Q

which pulse sequence add another inversion pulse to null signal from FAT AND BLOOD
1. STIR
2. FLAIR
3. DIR
4. TIR

A

4

125
Q

what is the null point of fat

A

0.69 x T1 time

126
Q

what is the definition of null point

A

time it takes a certain tissue to recover from full inversion to the transverse plane

127
Q
A

MRI (5 decks)

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