Part D: Fundamentals Flashcards
1
Q
- In the equation associated with Larmor Equation, B₀ stands for:
a. Static magnetic field
b. Frequency
c. Gyromagnetic ratio
d. Voltage
A
a. Static magnetic field
2
Q
- In the equation associated with Larmor Equation, ω₀ stands for:
a. Static magnetic field
b. Frequency
c. Gyromagnetic ratio
d. voltage
A
b. Frequency
3
Q
- In the equation associated with Larmor Equation, y stands for:
a. Static magnetic field
b. Frequency
c. Gyromagnetic ratio
d. voltage
A
c. Gyromagnetic ratio
4
Q
- A magnetic field strength of 0.5T is equivalent to:
a. 15 000 G
b. 5 000 G
c. 1 G
d. 10 000G
A
b. 5 000 G
5
Q
- A condition whereby there are MORE spins ‘in line’ with the magnetic field than ‘opposed’ is known as:
a. Low energy
b. High energy
c. Thermal equilibrium
d. Excitation
A
c. Thermal equilibrium
6
Q
- During thermal equilibrium there are:
a. More spins in the low energy state
b. More spins in the high energy state
c. Equal number spins in the low and high energy state
d. Less spins in the low energy state
A
a. More spins in the low energy state
7
Q
- Proton spins that are ‘in line’ with the static magnetic field (B₀) are referred to as all of the following EXCEPT:
a. Spin up
b. Parallel
c. Low energy spins
d. High energy spins
A
d. High energy spins
8
Q
- The microscopic magnetic field associated with the proton within the magnetic field is known as the:
a. Free induction decay (FID)
b. Magnetic moment (μ)
c. Signal echo (SE)
d. Field of view (FOV)
A
b. Magnetic moment (μ)
9
Q
- During thermal equilibrium, the vector that represents the ‘spin excess’ is known as the:
a. Free induction decay (FID)
b. Net magnetisation vector (NMV)
c. Signal echo (SE)
d. Field of view (FOV)
A
b. Net magnetisation vector (NMV)
10
Q
- The RF pulse is applied to achieve a condition known as:
a. Thermal equilibrium
b. Excitation
c. Relaxation
d. Scan timing
A
b. Excitation
11
Q
- During excitation, all of the following occur EXCEPT:
a. Low energy spins enter the high energy state
b. Spins begin to precess ‘in phase’
c. The net magnetisation is transferred into the transverse (x/y) plane
d. High energy spins return to the low energy state
A
d. High energy spins return to the low energy state
12
Q
- During relaxation, all of the following occur EXCEPT:
a. Low energy spins enter the high energy state
b. High energy spins return to the low energy state
c. Spins begin to precess ‘out of phase’ or lose phase coherence
d. The net magnetisation recovers longitudinally
A
a. Low energy spins enter the high energy state
13
Q
- T1 relaxation is also known as all of the following EXCEPT:
a. T1 recovery
b. Spin lattice
c. Longitudinal recovery or relaxation
d. Spin-spin
A
d. Spin-spin
14
Q
- T2 relaxation is also known as:
a. T1 recovery
b. Spin lattice
c. Longitudinal recovery or relaxation
d. Spin-spin
A
d. Spin-spin
15
Q
- T2 relaxation is also known as all of the following EXCEPT:
a. T2 decay
b. Spin lattice
c. Spin-spin
d. Transverse relaxation
A
b. Spin lattice
16
Q
- T1 relaxation tim eis define as when:
a. 76% of the longitudinal magnetisation has regrown
b. 63% of the longitudinal magnetisation has regrown
c. 63% of the transverse magnetisation has regrown
d. 76% of the transverse magnetisation has regrown
A
b. 63% of the longitudinal magnetisation has regrown
17
Q
- T2 relaxation tim ei sdefined as when:
a. 76% of the longitudinal magnetisation has regrown
b. 63% of the longitudinal magnetisation has regrown
c. 63% of the transverse magnetisation has regrown
d. 76% of the transverse magnetisation has regrown
A
c. 63% of the transverse magnetisation has regrown
18
Q
- Images acquired with a spin echo pulse sequence having a SHORT TR and TE values yield images known as (Figure D.1):
a. T1W1
b. T2WI
c. PDWI
d. Diffusion images
A
a. T1W1
(Figure D.1):
19
Q
- Images acquired with a spin echo pulse sequence having LONG TR and TE values yield image known as (Figure D.1):
a. T1W1
b. T2WI
c. PDWI
d. Diffusion images
A
b. T2WI
(Figure D.1):
20
Q
- Images acquired with a spin echo pulse sequence having LONG TR an SHORT TE values yield images known as (Figure D.1):
a. T1W1
b. T2WI
c. PDWI
d. Diffusion images
A
c. PDWI
(Figure D.1):
21
Q
- Spin density is another term for (Figure D.1):
a. Nuclear density
b. Spin density
c. Proton density
d. b and c
A
b. Spin density
(Figure D.1):
22
Q
- Spin density is determined by the (Figure D.1):
a. Amount of excess spins in the low energy state at equilibrium
b. Amount of transverse magnetisation at the time the echo is sampled
c. T1/T2
d. Amount of excess spins in the high energy state equilibrium
A
a. Amount of excess spins in the low energy state at equilibrium
(Figure D.1):
23
Q
- Gradient echo (steady-state) sequences acquired with short TR and flip angle combinations along with a moderately long TE yield images with (Figure D.1):
a. T1 contrast
b. T2 contrast
c. PF contrast
d. T2* contrast
A
d. T2* contrast
24
Q
- T2 + T2’ equals (Figure D.1):
a. T1
b. T2
c. PD
d. T2*
A
d. T2*
25
Q
- The LOGICAL gradient that is used for slice selection for the acquisition of an axial slice is the:
a. x
b. y
c. z
d. A combination of gradients
A
c. z
26
Q
- The PHYSICAL gradient that is used for slice selection for the acquisition of an axial slice is the:
a. x
b. y
c. z
d. A combination of gradients
A
c. z
27
Q
- The LOGICAL gradient that is used for the lice selection for the acquisition of a sagittal slice is the:
a. x
b. y
c. z
d. A combination of gradients
A
c. z
28
Q
- The PHYSICAL gradient that is used for slice selection for the acquisition of a sagittal slice is the:
a. x
b. y
c. z
d. A combination of gradients
A
a. x
29
Q
- The LOGICAL gradient that is used for phase encoding for the acquisition of an axial slice of the abdomen is the:
a. x
b. y
c. z
d. A combination of gradients
A
b. y
30
Q
- The LOGICAL gradient that is used for phase encoding for the acquisition of an axial slice of the head is the:
a. x
b. y
c. z
d. A combination of gradients
A
b. y
31
Q
- The PHYSCIAL gradient that is sued for phase encoding for the acquisition of an axial slice of the abdomen is the:
a. x
b. y
c. z
d. A combination of gradients
A
b. y
32
Q
- The PHYSICAL gradient that is used for phase encoding for the acquisition of an axial slice of the head is:
a. x
b. y
c. z
d. A combination of gradients
A
a. x
33
Q
- The receiver bandwidth is related to the slope of the:
a. Frequency-encoding gradient
b. Phase-encoding gradient
c. Slice-selecting gradient
d. Transmitting gradient
A
a. Frequency-encoding gradient
34
Q
- Following a 90° RF pulse, the signal that is created is called:
a. Spin echo
b. Gradient echo
c. Free induction decay
d. FRE
A
c. Free induction decay
35
Q
- T2* is a result of dephasing due to a tissue’s T2 time and:
a. T1
b. Susceptibility, inhomogeneities, and chemical shift
c. Molecular weight
d. a and b
A
b. Susceptibility, inhomogeneities, and chemical shift
36
Q
- The peak signal strength of a spin echo is less than the initial signal strength of the free induction decay because of:
a. T1 relaxation
b. T2* decay
c. Spin density changes
d. T2 relaxation
A
d. T2 relaxation
37
Q
- An example of a dipole is:
a. A hydrogen nucleus
b. A bar magnet
c. The earth
d. a, b, and c
A
d. a, b, and c
38
Q
- A vector has both direction and:
a. Purpose
b. Current
c. Magnitude
d. A fractional equivalent force
A
c. Magnitude
39
Q
- Hydrogen nuclei have a magnetic moment because they possess a property called:
a. Inversion
b. Flux
c. Spin
d. Resonance
A
c. Spin
40
Q
- When placed in a large static magnetic field, hydrogen nuclei:
a. Align with the magnetic field
b. Align in either a parallel or antiparallel position
c. Oscillate
d. Relax
A
b. Align in either a parallel or antiparallel position
41
Q
- Spins aligned in the antiparallel direction are in:
a. An expanded energy state
b. A resonant condition
c. A high-energy state
d. A constant sate of flux
A
c. A high-energy state
42
Q
- During thermal equilibrium, the spin excesses of individual hydrogen nuclei add to form:
a. A rotating vector
b. An oscillating vector
c. A varying vector
d. A net magnetisation vector
A
d. A net magnetisation vector
43
Q
- The formula that describes the relationship between the static magnetic field and the precessional frequency of the hydrogen protons is the:
a. Helholtz relationship
b. Nyquist theorem
c. Larmor equation
d. Bloch equation
A
c. Larmor equation
44
Q
- To calculate the precessional frequency, the strength of the static magnetic field is multiplied by a constant known as the:
a. Gyromagnetic ratio
b. Tau
c. Alpha- 1
d. Linear attenuation coefficient
A
a. Gyromagnetic ratio
45
Q
- The condition reached within a few seconds of hydrogen being paced in a magnetic field is described as:
a. Resonance
b. Free induction decay
c. Phase coherence
d. Thermal equilibrium
A
d. Thermal equilibrium
46
Q
- During thermal equilibrium, the individual protons precess:
a. At the same frequency
b. In phase
c. Out of phase
d. Slower
A
c. Out of phase
47
Q
- In order for energy to transfer between systems, the two systems must be at the same:
a. Phase location
b. Energy level
c. Mass
d. Resonant frequency
A
d. Resonant frequency
48
Q
- Assuming a TR sufficient for full recovery of longitudinal magnetisation, maximum signal is produced in the receiver coil when the net magnetisation is tipped:
a. 180°
b. 90°
c. Away from the z axis
d. Through the transverse plane
A
b. 90°
49
Q
- In relation to the static magnetic field (B₀), the RF field (B₁), is orientated:
a. Parallel
b. Perpendicular
c. At 180°
d. At 45°
A
b. Perpendicular
50
Q
- The RF energy used in MRI is classified as:
a. Electromagnetic radiation
b. Ionising radiation
c. Nonradiation energy
d. Investigational
A
a. Electromagnetic radiation
51
Q
- Immediately on the application of the 90° pulse, the precessing protons:
a. All flip to the high energy state
b. Tip into the transverse plane
c. Begin to precess in phase
d. a and b
A
c. Begin to precess in phase
52
Q
- The MR signal is produced by magnetisation:
a. Out of phase
b. In the longitudinal direction
c. Decayed
d. In the transverse plane
A
d. In the transverse plane
53
Q
- Frequency can be defined by the:
a. Rate of phase change per unit time
b. Phase/2
c. Fourier equation
d. Amplitude of the signal
A
a. Rate of phase change per unit time
54
Q
- Gradient magnetic fields are used to:
a. Improve the SNR
b. Spatially encode the data
c. Transmit the RF pulse
d. Control the image contrast
A
b. Spatially encode the data
55
Q
- Slice thickness is controlled by:
a. Length of the gradient field
b. Slope of the gradient
c. Receiver bandwidth
d. a and b
A
b. Slope of the gradient
56
Q
- The physical gradient along the bore of a superconducting magnet is the:
a. x gradient
b. x, y gradient
c. y gradient
d. z gradient
A
d. z gradient
57
Q
- To produce a sagittal slice, the physical gradient used during the excitation pulse is the:
a. z gradient
b. y gradient
c. x gradient
d. a and b
A
c. x gradient
58
Q
- The gyromagnetic ratio for hydrogen is:
a. 63.86 MHz/T
b. 42.6 MHz/T
c. 1 G/cm
d. 4 W/kg
A
b. 42.6 MHz/T
59
Q
- In a 0.5-T imager, the precessional frequency of hydrogen is approximately:
a. 63.86 MHz
b. 42.6 MHz
c. 21.3 MHz
d. 0.5 MHz
A
c. 21.3 MHz
60
Q
- The amount of RF energy necessary to produce a 45° flip angle is determined by the:
a. Coil being used
b. Amplitude (power) and duration of the RF pulse
c. Strength of the external magnetic field
d. All of the above
A
d. All of the above
61
Q
- The gradient that varies in amplitude with each TR is the:
a. Phase-encoding gradient
b. Frequency-encoding gradient
c. Slice selecting gradient
d. a and b
A
a. Phase-encoding gradient
62
Q
- The gradient that is on during the sampling of the echo is the:
a. Phase-encoding gradient
b. Frequency-encoding gradient
c. Slice selecting gradient
d. a and b
A
b. Frequency-encoding gradient
63
Q
- K-space is:
a. The image in its natural state
b. A negative of an MR image
c. The raw data from which an MR image is created
d. What comes after J space
A
c. The raw data from which an MR image is created
64
Q
- Multiple coil elements combined with multiple receiver channels is a:
a. Quadrature coil
b. Surface coil
c. Linear coil
d. Phased array coil
A
d. Phased array coil
