Pregunta 1
Pregunta
The precessional frequency of hydrogen at 1.5 telsa is
Respuesta
-
42.6MHz
-
63.86MHz
-
63.86KHz
-
21.28KHz
Pregunta 2
Pregunta
More questions regarding precessional frequency at 1.0T
Pregunta 3
Pregunta
Even more questions regarding precessional frequency at 0.5T
Pregunta 4
Pregunta
The coils used to alter the magnetic field during scanning are known as the
Respuesta
-
RF receive coils
-
RF transmit coils
-
Shim coils
-
Gradient coils
Pregunta 5
Pregunta
The precessional frequency of hydrogen nuclei that experience increased magnetic field strength due to gradient coils
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 6
Pregunta
The precessional frequency of hydrogen nuclei that experience decreased magnetic field strength due to gradient coils
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 7
Pregunta
There are how many pairs of gradient coils in a standard MRl system
Respuesta
-
1 pair
-
2 pairs
-
3 pairs
-
4 pairs
Pregunta 8
Pregunta
The Z gradient alters the magnetic field strength along which axis
Respuesta
-
Horizontal axis
-
Vertial axis
-
Long axis
-
Short axis
Pregunta 9
Pregunta
The Y gradient alters the magnetic field strength along which axis
Respuesta
-
Horizontal axis
-
Vertical axis
-
Long axis
-
Short axis
Pregunta 10
Pregunta
The X gradient alters the magnetic field strength along which axis
Respuesta
-
Horizontal axis
-
Vertical axis
-
Long axis
-
Short axis
Pregunta 11
Pregunta
The center of the magnet where the magnetic field strength remains unchanged even during the application of gradient magnetic fields is known as the
Respuesta
-
Pericenter
-
Isocenter
-
Monocenter
-
None of above
Pregunta 12
Pregunta
The three primary functions that gradients perform during MR scanning are
Respuesta
-
Slice selection, RF application, Frequency encoding
-
Phase encoding, Frequency encoding, RF application
-
Slice selection, Phase encoding, Frequency encoding
-
None of the above
Pregunta 13
Pregunta
During slice selection, the Z gradient is used to select slices in which plane
Respuesta
-
Coronal
-
Axial
-
Saggital
-
None of the above
Pregunta 14
Pregunta
During slice selection, the X gradient is used to select slices in which plane
Respuesta
-
Coronal
-
Axial
-
Saggital
-
None of the above
Pregunta 15
Pregunta
During slice selection, the Y gradient is used to select slices in which plane
Respuesta
-
Coronal
-
Axial
-
Saggital
-
None of the above
Pregunta 16
Pregunta
During the acquisition of sagittal images with the frequency direction S/I, phase encoding is conducted by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 17
Pregunta
During the acquisition of coronal images with the frequency direction S/I, phase encoding is conducted by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of above
Pregunta 18
Pregunta
During the acquisition of axial images of the brain with the frequency direction A/P, phase encoding is performed by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 19
Pregunta
During the acquisition of axial images of the body with the frequency direction L/R, phase encoding is performed by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 20
Pregunta
During the acquisition of sagittal images with the phase direction A/P, frequency encoding is performed by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 21
Pregunta
During the acquisition of coronal images with the phase direction L/R, frequency encoding is conducted by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 22
Pregunta
During the acquisition of axial images of the body with the phase direction A/P, frequency encoding is performed by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 23
Pregunta
During the acquisition of axial images of the brain with the phase direction L/R, frequency encoding is performed by which physical gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
-
None of the above
Pregunta 24
Pregunta
In MR imaging, slice thickness is determined by which factor(s)
Pregunta 25
Pregunta
In MRI, thin slices are achieved by applying a _______ gradient slope or a ______ bandwidth
Respuesta
-
Shallow, broad
-
Steep, narrow
-
Shallow, narrow
-
None of the above
Pregunta 26
Pregunta
In MRI, thick slices are achieved by applying a ________ gradient slope or a
_______ bandwidth
Respuesta
-
Shallow, broad
-
Steep, narrow
-
Shallow, narrow
-
None of the above
Pregunta 27
Pregunta
The range of frequencies that is sampled during frequency encoding is known as the
Respuesta
-
Receive bandwidth
-
Transmit bandwidth
-
Gradient slope
-
None the above
Pregunta 28
Pregunta
The range of frequencies that is transmitted by the RF pulse is known as the
Respuesta
-
Receive bandwidth
-
Transmit bandwidth
-
Gradient slope
-
None of the above
Pregunta 29
Pregunta
In MR imaging, the interslice gap is determined by which factor(s)
Respuesta
-
Slice selection gradient slope
-
Slice thickness
-
External magnetic field strength
-
Slice selection gradient slope & Slice thickness
Pregunta 30
Pregunta
The gradient that is turned on during the application of the 90 degree excitation pulse and the 180 degree RF pulse is known as
Pregunta 31
Pregunta
The gradient that is turned on during signal sampling is known as the
Pregunta 32
Pregunta
The gradient that is turned on just before the 180 degree rephasing pulse is known as the
Pregunta 33
Pregunta
The amplitude ofthe phase and frequency encoding gradients determines the dimension of what parameter
Pregunta 34
Pregunta
The frequency encoding gradient is also known as the _______ because it is turned on during the sampling of signal
Respuesta
-
Refocusing gradient
-
Spoiler gradient
-
Readout gradient
-
Phase encoding gradient
Pregunta 35
Pregunta
The theorem that states that a frequency must be sampled at least twice in order to reproduce it reliably is known as the
Respuesta
-
Pathagarum theorem
-
Nyquist theorem
-
Larmor theorem
-
Fourier theorem
Pregunta 36
Pregunta
The rate at which signal samples are taken during frequency encoding is known as the
Respuesta
-
Readout rate
-
Frequency rate
-
Sampling rate
-
None of the above
Pregunta 37
Pregunta
During the sampling of signal, the sampling rate is directly proportional to the
Respuesta
-
Sampling time
-
Receive bandwidth
-
Transmit bandwidth
-
None of the above
Pregunta 38
Pregunta
During the sampling of the signal, the sampling time is inversely proportional to
Pregunta 39
Pregunta
The spacial location of signal according to its precessional phase is known
Respuesta
-
Slice selection
-
Phase encoding
-
Frequency encoding
-
Readout
Pregunta 40
Pregunta
The spacial location of signal according to its precessional frequency is known as
Respuesta
-
Slice selection
-
Phase encoding
-
Frequency encoding
-
Spoiling
Pregunta 41
Pregunta
The area within the array processor where spatially located information is stored is known as
Respuesta
-
Interspace
-
Array space
-
Fourier space
-
K space
Pregunta 42
Pregunta
The magnitude of the phase shifts between two points within a patient is determined by which factor
Pregunta 43
Pregunta
The process that uses mathematical conversions to calculate the amplitude of individual frequencies is known as
Pregunta 44
Pregunta
The number of times each signal is sampled with the same value of the phase encoding gradient is known as
Pregunta 45
Pregunta
The higher the number of excitations that are acquired the more K space that is filled
Pregunta 46
Pregunta
In conventional spin echo sequences, how many phase encoding steps must be selected to fill 128 lines of K space
Pregunta 47
Pregunta
In conventional spin echo sequences, how many phase encoding steps must be selected to fill 256 lines of K space
Pregunta 48
Pregunta
Which parameter(s) effect total scan time
Pregunta 49
Pregunta
During a conventional spin echo pulse sequence, each slice is selected, phase encoded, and frequency encoded once per TR
Pregunta 50
Pregunta
The horizontal axis of K space represents which axis of the image (with corrected answer)
Respuesta
-
Phase encoding
-
Frequency encoding
-
Slice selection
-
None of the above
Pregunta 51
Pregunta
The vertical axis of K space represents which axis of the image (with corrected answer)
Respuesta
-
Phase encoding
-
Frequency encoding
-
Slice selection
-
None of the above
Pregunta 52
Pregunta
The area of K space filled with the shallowest phase encoding slopes is known as
Respuesta
-
Central lines
-
Outer lines
-
Negative lines only
-
None of the above
Pregunta 53
Pregunta
The area of K space that is filled with the steepest phase encoding gradient slopes is known as
Respuesta
-
Central lines
-
Outer lines
-
Positive lines only
-
None of the above
Pregunta 54
Pregunta
Image data along both the phase and frequency axis with the highest signal amplitude is stored in which area of K space
Respuesta
-
Central lines
-
Outer lines
-
Positive lines only
-
None of the above
Pregunta 55
Pregunta
Image data along both the phase and frequency axis with the lowest signal amplitude is stored in which area of the K space
Respuesta
-
Central lines
-
Outer lines
-
Positive lines only
-
None of the above
Pregunta 56
Pregunta
When the phase encoding gradient is activated, steep slopes produce what type of signal amplitude
Respuesta
-
High
-
Low
-
Medium
-
None of the above
Pregunta 57
Pregunta
When the phase encoding gradient is activated, shallow slopes produce what type of signal amplitude
Respuesta
-
High
-
Low
-
Medium
-
None of the above
Pregunta 58
Pregunta
When the phase encoding gradient is activated, medium slopes produce what type of signal amplitudes
Respuesta
-
High
-
Low
-
Medium
-
None of the above
Pregunta 59
Pregunta
When the amplitude of the phase encoding gradient increases, the amount of phase shift along the gradient
Respuesta
-
Increases
-
Decreases
-
Stays the same
-
None of the above
Pregunta 60
Pregunta
When the phase encoding gradient is activated, steep slopes produce data with what type of spatial resolution
Respuesta
-
High
-
Low
-
Medium
-
None of the above
Pregunta 61
Pregunta
Image data with high spatial resolution is stored in which area of K space
Respuesta
-
Outer lines
-
Central lines
-
Negative lines only
-
Positive lines only
Pregunta 62
Pregunta
Image data with low spatial resolution is stored in which area of K space
Respuesta
-
Outer lines
-
Central lines
-
Negative lines only
-
Positive lines only
Pregunta 63
Pregunta
The process of filling K space by sampling only half of the echo and interpolating the rest is known as
Pregunta 64
Pregunta
The process of filling only a percentage of K space with acquired data and filling the rest with zeros is known as
Respuesta
-
Partial saturation
-
Partial averaging
-
Partial voluming
-
Partial echo
Pregunta 65
Pregunta
Which method of image acquisition acquires all of the data from one slice before acquiring data from the next slice
Respuesta
-
Sequential
-
2D volumetric
-
3D volumetric
-
None of the above
Pregunta 66
Pregunta
Which method of image acquisition fills one line of K space for each slice in the sequence before it moves to the second line of K space
Respuesta
-
Sequential
-
2D volumetric
-
3D volumetric
-
None of the above
Pregunta 67
Pregunta
Which method ofimage acquisition acquires data from an entire volume of tissue, then uses a method called slice encoding to separate the images
Respuesta
-
Sequential
-
2D volumetric
-
3D volumetric
Pregunta 68
Pregunta
The thickness of an MRI image can be changed by which of the following methods
Respuesta
-
Altering the gradient slope
-
Changing the number of excitations
-
Altering the RF bandwidth
-
Altering the gradient slope & Altering the RF bandwidth
Pregunta 69
Pregunta
The term used to describe a volume element is known as
Respuesta
-
Pixel
-
Pixie
-
Voxel
-
Picture element
Pregunta 70
Pregunta
The number of picture elements used to make up an image is known as
Respuesta
-
Contrast
-
Matrix
-
Signal to noise
-
None of the above
Pregunta 71
Pregunta
The ability to distinguish one structure from another on an image is known as
Respuesta
-
Spatial resolution
-
Contrast to noise
-
Signal to noise
-
None of the above
Pregunta 72
Pregunta
The term used to describe a picture element is known as a
Respuesta
-
Image element
-
Pixel
-
Voxel
-
Volume element
Pregunta 73
Pregunta
The size of the area being displayed on an MR image is known as
Respuesta
-
Field of view
-
Voxel size
-
Pixel size
-
None of the above
Pregunta 74
Pregunta
The depth of a volume element is determined by what parameter
Respuesta
-
Matrix
-
NEX
-
Repetition time
-
Slice thickness
Pregunta 75
Pregunta
The height and width of a picture element is determined by what parameter(s)
Pregunta 76
Pregunta
A volume element that has the same height, width, and depth is known
as
Respuesta
-
Rectangular
-
Isotropic
-
Triangular
-
Anisotropic
Pregunta 77
Pregunta
A voxel that is unequal in height, width, and depth is known as
Respuesta
-
Isotropic
-
Triangular
-
Squared
-
Anisotropic
Pregunta 78
Pregunta
Three characteristics commonly used to define the quality of an MRl image are
Respuesta
-
Contrast, Resolution, Matrix
-
Resolution, Contrast, Signal to Noise
-
Signal to Noise, Excitations, Contrast
-
Resolution, Matrix, Signal to Noise
Pregunta 79
Pregunta
The difference in brightness between two regions of an image is known
Respuesta
-
Signal to noise
-
Image contrast
-
Spatial resolution
-
None of the above
Pregunta 80
Pregunta
Bright pixels on an MRI image represent what type of signal
Respuesta
-
Low
-
High
-
Weak
-
None of the above
Pregunta 81
Pregunta
The clarity with which different areas of an image are distinguished is known
as
Respuesta
-
Image contrast
-
Signal to noise
-
Spatial resolution
-
None of the above
Pregunta 82
Pregunta
The proportion of signal actually used to construct an image relative to the amount of background noise is known as
Respuesta
-
Spatial resolution
-
Signal to noise ratio
-
Image contrast
-
None of the above
Pregunta 83
Pregunta
An image with a grainy appearance usually represents an image with
Respuesta
-
High resolution
-
Low signal to noise
-
High signal to noise
-
Low resolution
Pregunta 84
Pregunta
Noise that degrades image quality in a specific location within an MRI image is known as
Respuesta
-
Inherent noise interference
-
Random noise interference
-
Discrete noise interference
-
None of the above
Pregunta 85
Pregunta
Noise that generally degrades overall quality of an MRI image is known
Respuesta
-
Inherent noise interference
-
Random noise interference
-
Discrete noise interference
-
None of the above
Pregunta 86
Pregunta
Which of the following is a parameter that directly affects signal to noise ratio
Respuesta
-
Voxel size
-
Number of excitations
-
Repetition time
-
All of the above
Pregunta 87
Pregunta
The term "Trade-off parameters" is used to describe parameters that affect each other inversely
Pregunta 88
Pregunta
When magnetic field strength increases, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 89
Pregunta
When voxel size decreases, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 90
Pregunta
When pixel size increases, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 91
Pregunta
When bandwidth is increased, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 92
Pregunta
When repetition time is increased, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 93
Pregunta
When echo time is increased, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 94
Pregunta
When field of view decreases, spatial resolution
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 95
Pregunta
When field of view is increased, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 96
Pregunta
When the number of excitations is increased, spatial resolution
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 97
Pregunta
When image matrix is increased, spatial resolution
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 98
Pregunta
When slice thickness is increased, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 99
Pregunta
When slice spacing increases, signal to noise ratio
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 100
Pregunta
When image matrix is decreased, spatial resolution
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 101
Pregunta
When TE is decreased, the spatial resolution
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 102
Pregunta
When TR is increased, acquisition time
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 103
Pregunta
When the number of excitations is decreased, acquisition time
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 104
Pregunta
When image matrix increases, acquisition time
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 105
Pregunta
With the parameters given, which protocol gives the highest signal to noise ratio
Respuesta
-
Long TR/Short TE/High matrix
-
Short TR/Long TE/Low matrix
-
Long TR/Long TE/High matrix
-
Long TR/Short TE/Low matrix
Pregunta 106
Pregunta
With the parameters given, which protocol gives the highest spatial resolution
Respuesta
-
Thick slice/Large FOV/High matrix
-
Thin slice/Large FOV/High matrix
-
Thin slice/Small FOV/Low matrix
-
Thin slice/Small FOV/High matrix
Pregunta 107
Pregunta
With the parameters given, which protocol has the longest acquisition time
Respuesta
-
Long TR/Low NEX/Low matrix
-
Short TR/High NEX/Low matrix
-
Short TR/Low NEX/High matrix
-
Long TR/High NEX/High matrix
Pregunta 108
Pregunta
With the parameters given, which protocol gives the highest signal to noise ratio
Respuesta
-
Thick slice/Low TE/Large FOV
-
Thin slice/High TE/Small FOV
-
Thick slicelHigh TE/Small FOV
-
Thin slice/Low TE/Small FOV
Pregunta 109
Pregunta
As bandwidth increases, sampling time
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 110
Pregunta
As bandwidth decreases, sampling time
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 111
Pregunta
Which of the following 'logical' gradients is known as the frequency encoding gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
Pregunta 112
Pregunta
Which of the following 'logical' gradients is known as the phase encoding gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
Pregunta 113
Pregunta
Which of the following 'logical' gradients is known as the slice selection gradient
Respuesta
-
X gradient
-
Y gradient
-
Z gradient
Pregunta 114
Pregunta
In plane pixel size can be determined by which of the following methods
Respuesta
-
Dividing the FOY by the number phase and frequency steps
-
Dividing the NEX by the FOV
-
Dividing the TR by the NEX
-
Dividing the TR by the slice thickness
Pregunta 115
Pregunta
Which of the following is the formula for determining scan time for a 3D FT pulse sequence
Respuesta
-
TR x NEX x phase steps x number of slices
-
TR x NEX x phase steps
-
NEX x TR x number of slices
-
TR x phase steps x number of slices