Brainscape's Knowledge GenomeTM

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


See full index

MRI in practice 5th ed. > Chapter 2 > Flashcards

Chapter 2 Flashcards

Image weighting & contrast

1
Q

The T1 process is also known as:

a. Spin-spin
b. Spin density
c. Spin-lattice
d. Spin-warp

A

c. Spin-lattice

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

The T2 process is also known as:

a. Spin-spin
b. Spin density
c. Spin-lattice
d. Spin-warp

A

a. Spin-spin

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

T1 relaxation time is defined as:

a. 37% of the longitudinal magnetization has regrown
b. 63% of the transverse magnetization has decayed
c. 37% of the transverse magnetization has decayed
d. 63% of the longitudinal magnetization has regrown

A

d. 63% of the longitudinal magnetization has regrown

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

Repetition time is the parameter that is manipulated to control what relaxation?

a. T2
b. T2*
c. T1
d. PD

A

c. T1

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

Tissues with long T1 times regain their longitudinal magnetization:

a. Completely
b. Partially
c. Quickly
d. Slowly

A

d. Slowly

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

The rate of regrowth of the net magnetization along the longitudinal direction is known as:

a. T2*
b. resonance
c. T1
d. repetition time

A

c. T1

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

The decay of magnetization from the x-y plane is known as:

a. Spin-spin Relaxation
b. Spin-lattice Relaxation
c. Longitudinal relaxation
d. T1 relaxation

A

a. Spin-spin Relaxation

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

The phenomenon in which the transverse magnetization decays is called:

a. T1 Relaxation
b. precession
c. T2 Relaxation
d. resonance

A

c. T2 Relaxation

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

The phenomenon in which one proton transfers energy to another is called:

a. Rephasing
b. Precession
c. Dephasing
d. Spin-spin interaction

A

d. Spin-spin interaction

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

MTC saturation band is used to:

a. Diminish partial volume averaging
b. Improve spatial resolution
c. Saturate free protons
d. Saturate bound protons

A

d. Saturate bound protons

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

Bound protons tend to have shorter T1 and T2 relaxation times than free protons.

a. True
b. False

A

a. True

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

Which of the following parameters control the amount of contrast seen in an image due to T2 relaxation?

a. TE
b. TR
c. TI
d. None of these

A

a. TE

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

What type of contrast would result from combining a long TR and a long TE?

a. T1 contrast
b. T2 contrast
c. Proton Density contrast
d. None of these

A

b. T2 contrast

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

On a T2 weighted image, CSF appears bright since it has a:

a. short T2 relaxation time
b. short T1 relaxation time
c. long T2 relaxation time
d. long T1 relaxation time

A

c. long T2 relaxation time

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

What type of contrast would result from combining a short TR and a short TE:

a. T1 contrast
b. T2 contrast
c. Proton Density
d. None of these

A

a. T1 contrast

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

Full saturation results when:

a. The signal relaxes to 90 degrees
b. The NMV is pushed to 180 degrees
c. A variable flip angle is used
d. None of these

A

b. The NMV is pushed to 180 degrees

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

Partial saturation occurs:

a. After the excitation pulse
b. After the rephasing pulse
c. Before the TE is received
d. With a flip angle larger than 90 degrees

A

d. With a flip angle larger than 90 degrees

18
Q

Flip angles are affected by:

a. Strength and duration of the RF pulse
b. T1 & T2 parameters of the receiving signal
c. Proton Density
d. Echo time

A

a. Strength and duration of the RF pulse

19
Q

With a proton density weighted study:

a. Low density tissues appear bright
b. High density tissues appear bright
c. High density tissues appear dark
d. Low density tissues induce a large signal in the coil

A

b. High density tissues appear bright

20
Q

A long TR and a short TE results in:

a. A T1 weighted image
b. A PD weighted image
c. A T2 weighted image
d. A gradient image

A

b. A PD weighted image

21
Q

Tissues efficient at both T1 and T2 interactions and have low (short) relaxation times, therefore have:

a. High T1 values
b. High relaxation rates
c. High T2 values
d. Low relaxation rates

A

b. High relaxation rates

22
Q

As the NMV precesses within the transverse plane, it induces an electrical current in a:

a. Gradient coil
b. Shim coil
c. B0
d. Radio-frequency coil

A

d. Radio-frequency coil

23
Q

Once the NMV has moved away from equilibrium, the following will occur:

a. The longitudinal component will increase
b. The transverse component will decrease
c. The longitudinal component will stay the same
d. The transverse component will increase

A

d. The transverse component will increase

24
Q

__________ contrast parameters are those that cannot be changed because they are inherent to the body’s tissues.

a. Extrinsic
b. TR
c. Intrinsic
d. TE

A

c. Intrinsic

25
Q

Fat molecules consist of large molecules, closely packed together, called:

a. Histidines
b. Lipids
c. Glycines
d. Steroids

A

b. Lipids

26
Q

Images characterized by bright fat and dark water are:

a. T1 weighted
b. T2 weighted
c. Proton density weighted
d. Nuclear density weighted

A

a. T1 weighted

27
Q

The intrinsic contrast mechanism with regard to fMRI is:

a. Faraday’s law of induction
b. chemical shift
c. flow-related enhancement
d. the BOLD effect

A

d. the BOLD effect

28
Q

Abnormal tissue has a high ADC (restricted diffusion) and high signal.

a. True
b. false

A

b. false

29
Q

Blood oxygenation level ________ (BOLD) produces MR signal intensity changes between stimulus and rest.

a. dependent
b. dosage
c. diffusion
d. data

A

a. dependent

30
Q

Which of the following would result in an image with the greatest amount of diffusion weighting?

a. b-value 750
b. b-value 450
c. b-value 825
d. b-value 1100

A

d. b-value 1100

31
Q

The main purpose of producing an ADC map is to:

a. reduce the contribution from diffusion effects
b. eliminate T2 shine-through
c. increase SNR
d. reduce T1 weighting

A

b. eliminate T2 shine-through

32
Q

Changing the b-value alters the:

a. amplitude, timing and/or duration of the diffusion gradients
b. amplitude of the phase encoding gradient
c. length of the readout gradient
d. spatial resolution

A

a. amplitude, timing and/or duration of the diffusion gradients

33
Q

The term used to describe the movement of molecules in the extra-cellular space due to random thermal motion is:

a. transference
b. osmosis
c. diffusion
d. perfusion

A

c. diffusion

34
Q

In a spin echo pulse sequence by decreasing the TR from 2000 ms to 600 ms, which of the following is the end result?

a. a stronger MRI signal
b. few protons would experience spin-spin interaction
c. better tissue contrast based on the tissue T2 characteristics
d. better tissue contrast based on the tissue T1 characteristics

A

d. better tissue contrast based on the tissue T1 characteristics

35
Q

The most serious risk of GBCA’s is

a. extravasation
b. nephrogenic systemic fibrosis
c. adverse reaction
d. allergic reaction

A

b. nephrogenic systemic fibrosis

36
Q

Nephrogenic systemic fibrosis has been reported only in patients with

a. normal kidney function
b. diabetes
c. serious decreased renal function
d. high blood pressure

A

c. serious decreased renal function

37
Q

The mechanism of T2 contrast enhancements agents is to:

a. Increase T2 relaxation time, therefore producing low signal
b. decrease T2 relaxation time, therefore producing low signal
c. increase T2 relaxation time, therefore producing high signal
d. decrease T2 relaxation time, therefore producing high signal

A

b. decrease T2 relaxation time, therefore producing low signal

38
Q

The mechanism of T1 contrast enhancements agents is to:

a. increase T1 relaxation time, therefore producing low signal
b. decrease T1 relaxation time, therefore producing low signal
c. increase T1 relaxation time, therefore producing high signal
d. decrease T1 relaxation time, therefore producing high signal

A

d. decrease T1 relaxation time, therefore producing high signal

39
Q

Gadolinium is a rare earth metal (lanthanide), more commonly known as a _______ metal.

a. base
b. heavy
c. noble
d. precious

A

b. heavy

40
Q

Extrinsic contrast parameters include all expect:

a. TR
b. Flow
c. TE
d. b value

A

b. Flow

MRI in practice 5th ed. (10 decks)

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