Test
Practice Set (4) - Image Production
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Preguntas del test (115)
1The precessional frequency of hydrogen at 1.5 telsa is
- A42.6MHz
- B63.86MHz
- C63.86KHz
- D21.28KHz
2More questions regarding precessional frequency at 1.0T
- A1
- B2
3Even more questions regarding precessional frequency at 0.5T
- A1
- B2
4The coils used to alter the magnetic field during scanning are known as the
- ARF receive coils
- BRF transmit coils
- CShim coils
- DGradient coils
5The precessional frequency of hydrogen nuclei that experience increased magnetic field strength due to gradient coils
- AIncreases
- BDecreases
- CStays the same
6The precessional frequency of hydrogen nuclei that experience decreased magnetic field strength due to gradient coils
- AIncreases
- BDecreases
- CStays the same
7There are how many pairs of gradient coils in a standard MRl system
- A1 pair
- B2 pairs
- C3 pairs
- D4 pairs
8The Z gradient alters the magnetic field strength along which axis
- AHorizontal axis
- BVertial axis
- CLong axis
- DShort axis
9The Y gradient alters the magnetic field strength along which axis
- AHorizontal axis
- BVertical axis
- CLong axis
- DShort axis
10The X gradient alters the magnetic field strength along which axis
- AHorizontal axis
- BVertical axis
- CLong axis
- DShort axis
11The center of the magnet where the magnetic field strength remains unchanged even during the application of gradient magnetic fields is known as the
- APericenter
- BIsocenter
- CMonocenter
- DNone of above
12The three primary functions that gradients perform during MR scanning are
- ASlice selection, RF application, Frequency encoding
- BPhase encoding, Frequency encoding, RF application
- CSlice selection, Phase encoding, Frequency encoding
- DNone of the above
13During slice selection, the Z gradient is used to select slices in which plane
- ACoronal
- BAxial
- CSaggital
- DNone of the above
14During slice selection, the X gradient is used to select slices in which plane
- ACoronal
- BAxial
- CSaggital
- DNone of the above
15During slice selection, the Y gradient is used to select slices in which plane
- ACoronal
- BAxial
- CSaggital
- DNone of the above
16During the acquisition of sagittal images with the frequency direction S/I, phase encoding is conducted by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
17During the acquisition of coronal images with the frequency direction S/I, phase encoding is conducted by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of above
18During the acquisition of axial images of the brain with the frequency direction A/P, phase encoding is performed by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
19During the acquisition of axial images of the body with the frequency direction L/R, phase encoding is performed by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
20During the acquisition of sagittal images with the phase direction A/P, frequency encoding is performed by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
21During the acquisition of coronal images with the phase direction L/R, frequency encoding is conducted by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
22During the acquisition of axial images of the body with the phase direction A/P, frequency encoding is performed by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
23During the acquisition of axial images of the brain with the phase direction L/R, frequency encoding is performed by which physical gradient
- AX gradient
- BY gradient
- CZ gradient
- DNone of the above
24In MR imaging, slice thickness is determined by which factor(s)
- AMagnet field strength
- BGradient slope slice select
- CTransmit bandwidth
- DGradient slope slice select and Transmit bandwidth
25In MRI, thin slices are achieved by applying a _______ gradient slope or a ______ bandwidth
- AShallow, broad
- BSteep, narrow
- CShallow, narrow
- DNone of the above
26In MRI, thick slices are achieved by applying a ________ gradient slope or a
_______ bandwidth- AShallow, broad
- BSteep, narrow
- CShallow, narrow
- DNone of the above
27The range of frequencies that is sampled during frequency encoding is known as the
- AReceive bandwidth
- BTransmit bandwidth
- CGradient slope
- DNone the above
28The range of frequencies that is transmitted by the RF pulse is known as the
- AReceive bandwidth
- BTransmit bandwidth
- CGradient slope
- DNone of the above
29In MR imaging, the interslice gap is determined by which factor(s)
- ASlice selection gradient slope
- BSlice thickness
- CExternal magnetic field strength
- DSlice selection gradient slope & Slice thickness
30The gradient that is turned on during the application of the 90 degree excitation pulse and the 180 degree RF pulse is known as
- ASlice selection gradient
- BPhase encoding gradient
- CFrequency encoding gradient
- DNone of the above
31The gradient that is turned on during signal sampling is known as the
- ASlice selection gradient
- BPhase encoding gradient
- CFrequency encoding gradient
- DNone of the above
32The gradient that is turned on just before the 180 degree rephasing pulse is known as the
- ASlice selection gradient
- BPhase encoding gradient
- CFrequency encoding gradient
- DNone of the above
33The amplitude ofthe phase and frequency encoding gradients determines the dimension of what parameter
- AFOV
- BTR
- CTE
- DNEX
34The frequency encoding gradient is also known as the _______ because it is turned on during the sampling of signal
- ARefocusing gradient
- BSpoiler gradient
- CReadout gradient
- DPhase encoding gradient
35The theorem that states that a frequency must be sampled at least twice in order to reproduce it reliably is known as the
- APathagarum theorem
- BNyquist theorem
- CLarmor theorem
- DFourier theorem
36The rate at which signal samples are taken during frequency encoding is known as the
- AReadout rate
- BFrequency rate
- CSampling rate
- DNone of the above
37During the sampling of signal, the sampling rate is directly proportional to the
- ASampling time
- BReceive bandwidth
- CTransmit bandwidth
- DNone of the above
38During the sampling of the signal, the sampling time is inversely proportional to
- ASampling rate
- BTransmit bandwidth
- CReceive bandwidth
- DSampling rate & Receive bandwidth
39The spacial location of signal according to its precessional phase is known
- ASlice selection
- BPhase encoding
- CFrequency encoding
- DReadout
40The spacial location of signal according to its precessional frequency is known as
- ASlice selection
- BPhase encoding
- CFrequency encoding
- DSpoiling
41The area within the array processor where spatially located information is stored is known as
- AInterspace
- BArray space
- CFourier space
- DK space
42The magnitude of the phase shifts between two points within a patient is determined by which factor
- ASlope of the frequency encoding gradient
- BSlope of the phase encoding gradient
- CStrength of the RF pulse
- DNone of the above
43The process that uses mathematical conversions to calculate the amplitude of individual frequencies is known as
- AFast Fourier Transformation
- BFree induction decay
- CLamor equation
- DNone of the above
44The number of times each signal is sampled with the same value of the phase encoding gradient is known as
- ANumber of signal averages
- BNumber of excitations
- CNumber of signal quotients
- DAll of the above
45The higher the number of excitations that are acquired the more K space that is filled
- ATrue
- BFalse
46In conventional spin echo sequences, how many phase encoding steps must be selected to fill 128 lines of K space
- A64
- B128
- C192
- D256
47In conventional spin echo sequences, how many phase encoding steps must be selected to fill 256 lines of K space
- A64
- B128
- C192
- D256
48Which parameter(s) effect total scan time
- ARepetition time
- BNumber of phase encoding steps
- CNumber of excitations
- DAll of the above
49During a conventional spin echo pulse sequence, each slice is selected, phase encoded, and frequency encoded once per TR
- ATrue
- BFalse
50The horizontal axis of K space represents which axis of the image (with corrected answer)
- APhase encoding
- BFrequency encoding
- CSlice selection
- DNone of the above
51The vertical axis of K space represents which axis of the image (with corrected answer)
- APhase encoding
- BFrequency encoding
- CSlice selection
- DNone of the above
52The area of K space filled with the shallowest phase encoding slopes is known as
- ACentral lines
- BOuter lines
- CNegative lines only
- DNone of the above
53The area of K space that is filled with the steepest phase encoding gradient slopes is known as
- ACentral lines
- BOuter lines
- CPositive lines only
- DNone of the above
54Image data along both the phase and frequency axis with the highest signal amplitude is stored in which area of K space
- ACentral lines
- BOuter lines
- CPositive lines only
- DNone of the above
55Image data along both the phase and frequency axis with the lowest signal amplitude is stored in which area of the K space
- ACentral lines
- BOuter lines
- CPositive lines only
- DNone of the above
56When the phase encoding gradient is activated, steep slopes produce what type of signal amplitude
- AHigh
- BLow
- CMedium
- DNone of the above
57When the phase encoding gradient is activated, shallow slopes produce what type of signal amplitude
- AHigh
- BLow
- CMedium
- DNone of the above
58When the phase encoding gradient is activated, medium slopes produce what type of signal amplitudes
- AHigh
- BLow
- CMedium
- DNone of the above
59When the amplitude of the phase encoding gradient increases, the amount of phase shift along the gradient
- AIncreases
- BDecreases
- CStays the same
- DNone of the above
60When the phase encoding gradient is activated, steep slopes produce data with what type of spatial resolution
- AHigh
- BLow
- CMedium
- DNone of the above
61Image data with high spatial resolution is stored in which area of K space
- AOuter lines
- BCentral lines
- CNegative lines only
- DPositive lines only
62Image data with low spatial resolution is stored in which area of K space
- AOuter lines
- BCentral lines
- CNegative lines only
- DPositive lines only
63The process of filling K space by sampling only half of the echo and interpolating the rest is known as
- AFractional echo
- BGradient echo
- CPartial echo
- DFractional echo & Partial echo
64The process of filling only a percentage of K space with acquired data and filling the rest with zeros is known as
- APartial saturation
- BPartial averaging
- CPartial voluming
- DPartial echo
65Which method of image acquisition acquires all of the data from one slice before acquiring data from the next slice
- ASequential
- B2D volumetric
- C3D volumetric
- DNone of the above
66Which 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
- ASequential
- B2D volumetric
- C3D volumetric
- DNone of the above
67Which method ofimage acquisition acquires data from an entire volume of tissue, then uses a method called slice encoding to separate the images
- ASequential
- B2D volumetric
- C3D volumetric
68The thickness of an MRI image can be changed by which of the following methods
- AAltering the gradient slope
- BChanging the number of excitations
- CAltering the RF bandwidth
- DAltering the gradient slope & Altering the RF bandwidth
69The term used to describe a volume element is known as
- APixel
- BPixie
- CVoxel
- DPicture element
70The number of picture elements used to make up an image is known as
- AContrast
- BMatrix
- CSignal to noise
- DNone of the above
71The ability to distinguish one structure from another on an image is known as
- ASpatial resolution
- BContrast to noise
- CSignal to noise
- DNone of the above
72The term used to describe a picture element is known as a
- AImage element
- BPixel
- CVoxel
- DVolume element
73The size of the area being displayed on an MR image is known as
- AField of view
- BVoxel size
- CPixel size
- DNone of the above
74The depth of a volume element is determined by what parameter
- AMatrix
- BNEX
- CRepetition time
- DSlice thickness
75The height and width of a picture element is determined by what parameter(s)
- ASize of the FOV
- BNumber of phase encoding steps
- CNumber of frequency encoding steps
- DAll of the above
76A volume element that has the same height, width, and depth is known
as- ARectangular
- BIsotropic
- CTriangular
- DAnisotropic
77A voxel that is unequal in height, width, and depth is known as
- AIsotropic
- BTriangular
- CSquared
- DAnisotropic
78Three characteristics commonly used to define the quality of an MRl image are
- AContrast, Resolution, Matrix
- BResolution, Contrast, Signal to Noise
- CSignal to Noise, Excitations, Contrast
- DResolution, Matrix, Signal to Noise
79The difference in brightness between two regions of an image is known
- ASignal to noise
- BImage contrast
- CSpatial resolution
- DNone of the above
80Bright pixels on an MRI image represent what type of signal
- ALow
- BHigh
- CWeak
- DNone of the above
81The clarity with which different areas of an image are distinguished is known
as- AImage contrast
- BSignal to noise
- CSpatial resolution
- DNone of the above
82The proportion of signal actually used to construct an image relative to the amount of background noise is known as
- ASpatial resolution
- BSignal to noise ratio
- CImage contrast
- DNone of the above
83An image with a grainy appearance usually represents an image with
- AHigh resolution
- BLow signal to noise
- CHigh signal to noise
- DLow resolution
84Noise that degrades image quality in a specific location within an MRI image is known as
- AInherent noise interference
- BRandom noise interference
- CDiscrete noise interference
- DNone of the above
85Noise that generally degrades overall quality of an MRI image is known
- AInherent noise interference
- BRandom noise interference
- CDiscrete noise interference
- DNone of the above
86Which of the following is a parameter that directly affects signal to noise ratio
- AVoxel size
- BNumber of excitations
- CRepetition time
- DAll of the above
87The term "Trade-off parameters" is used to describe parameters that affect each other inversely
- ATrue
- BFalse
88When magnetic field strength increases, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
89When voxel size decreases, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
90When pixel size increases, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
91When bandwidth is increased, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
92When repetition time is increased, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
93When echo time is increased, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
94When field of view decreases, spatial resolution
- AIncreases
- BDecreases
- CStays the same
95When field of view is increased, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
96When the number of excitations is increased, spatial resolution
- AIncreases
- BDecreases
- CStays the same
97When image matrix is increased, spatial resolution
- AIncreases
- BDecreases
- CStays the same
98When slice thickness is increased, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
99When slice spacing increases, signal to noise ratio
- AIncreases
- BDecreases
- CStays the same
100When image matrix is decreased, spatial resolution
- AIncreases
- BDecreases
- CStays the same
101When TE is decreased, the spatial resolution
- AIncreases
- BDecreases
- CStays the same
102When TR is increased, acquisition time
- AIncreases
- BDecreases
- CStays the same
103When the number of excitations is decreased, acquisition time
- AIncreases
- BDecreases
- CStays the same
104When image matrix increases, acquisition time
- AIncreases
- BDecreases
- CStays the same
105With the parameters given, which protocol gives the highest signal to noise ratio
- ALong TR/Short TE/High matrix
- BShort TR/Long TE/Low matrix
- CLong TR/Long TE/High matrix
- DLong TR/Short TE/Low matrix
106With the parameters given, which protocol gives the highest spatial resolution
- AThick slice/Large FOV/High matrix
- BThin slice/Large FOV/High matrix
- CThin slice/Small FOV/Low matrix
- DThin slice/Small FOV/High matrix
107With the parameters given, which protocol has the longest acquisition time
- ALong TR/Low NEX/Low matrix
- BShort TR/High NEX/Low matrix
- CShort TR/Low NEX/High matrix
- DLong TR/High NEX/High matrix
108With the parameters given, which protocol gives the highest signal to noise ratio
- AThick slice/Low TE/Large FOV
- BThin slice/High TE/Small FOV
- CThick slicelHigh TE/Small FOV
- DThin slice/Low TE/Small FOV
109As bandwidth increases, sampling time
- AIncreases
- BDecreases
- CStays the same
110As bandwidth decreases, sampling time
- AIncreases
- BDecreases
- CStays the same
111Which of the following 'logical' gradients is known as the frequency encoding gradient
- AX gradient
- BY gradient
- CZ gradient
112Which of the following 'logical' gradients is known as the phase encoding gradient
- AX gradient
- BY gradient
- CZ gradient
113Which of the following 'logical' gradients is known as the slice selection gradient
- AX gradient
- BY gradient
- CZ gradient
114In plane pixel size can be determined by which of the following methods
- ADividing the FOY by the number phase and frequency steps
- BDividing the NEX by the FOV
- CDividing the TR by the NEX
- DDividing the TR by the slice thickness
115Which of the following is the formula for determining scan time for a 3D FT pulse sequence
- ATR x NEX x phase steps x number of slices
- BTR x NEX x phase steps
- CNEX x TR x number of slices
- DTR x phase steps x number of slices
Información
- Descripción
- Diploma MR Test sobre Practice Set (4) - Image Production, creado por S L el 23/01/2016.
- Autor
- S L
- Idioma
- English
- Visitas
- 111
- Etiquetas
- Valoración
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