Pregunta 1
Pregunta
Blood flow that has consistent velocities within a vessel is known
as what type offlow
Respuesta
-
Turbulent flow
-
Laminar flow
-
Vortex flow
-
Stagnant flow
Pregunta 2
Pregunta
Blood flow that has randomly different velocities is known as what type of
flow
Respuesta
-
Turbulent flow
-
Laminar flow
-
Vortex flow
-
Stagnant flow
Pregunta 3
Pregunta
Blood flow that has high velocities in the center of the vessel but spirals near
walls of a vessel due to a stricture is known as what type of flow
Respuesta
-
Turbulent flow
-
Laminar flow
-
Vortex flow
-
Stagnant flow
Pregunta 4
Pregunta
Blood flow that slows to a point of immobility is known as what type of flow
Respuesta
-
Turbulent flow
-
Laminar flow
-
Vortex flow
-
Stagnant flow
Pregunta 5
Pregunta
Blood flow velocity is measured in what type of unit
Respuesta
-
Gauss/sec
-
mm/sec
-
cm/sec
-
inches/sec
Pregunta 6
Pregunta
Which of the following is the formula that is used to calculate blood flow
velocity
Respuesta
-
Velocity = Flow volume / Vessel area
-
Velocity = Vessel area / Flow volume
-
Velocity = Flow volume + vessel area
-
Velocity = Vessel area - Flow volume
Pregunta 7
Pregunta
Blood flow velocity is greatest near which area of the vessel
Respuesta
-
Vessel walls
-
Vessel center
-
None of the above
Pregunta 8
Pregunta
Blood flow velocity at a given point is dependent upon which factor
Pregunta 9
Pregunta
During peak systolic phase of the cardiac cycle, blood flow velocities are
dependent upon what factor(s)
Pregunta 10
Pregunta
Which of the following vessels has the highest peak velocity
Respuesta
-
Ascending aorta
-
Distal aorta
-
Proximal carotids
-
Basilar artery
Pregunta 11
Pregunta
Which of the following vessels has the slowest peak velocity
Pregunta 12
Pregunta
Typical peak velocities of the ascending aorta are usually within what range
Respuesta
-
150 - 175 cm/sec
-
100 - 160 cm/sec
-
80 - 120 cm/sec
-
40 - 70 cm/sec
Pregunta 13
Pregunta
Typical peak velocities of the distal aorta and iliac vessels are usually
within what range
Respuesta
-
150 - 175 cm/sec
-
100 - 160 cm/sec
-
80 - 120 cm/sec
-
40 - 70 cm/sec
Pregunta 14
Pregunta
Typical peak velocities of the proximal carotid, brachial and superficial
femoral arteries are usually within what range
Respuesta
-
150 - 175 cm/sec
-
100 - 160 cm/sec
-
80 - 120 cm/sec
-
40 - 70 cm/sec
Pregunta 15
Pregunta
Typical peak velocities of the middle and anterior cerebral arteries are
usually within what range
Respuesta
-
150 - 175 cm/sec
-
100 - 150 cm/sec
-
40 - 70 cm/sec
-
30 - 50 cm/sec
Pregunta 16
Pregunta
Typical peak velocities of the vertebral and basilar arteries are usually within
what range
Respuesta
-
80 - 120 cm/sec
-
50-70 cm/sec
-
30-50 cm/sec
-
under 20 cm/sec
Pregunta 17
Pregunta
The speed at which blood flows through an excited slice and only receives
one RF pulse is known as what type of phenomenon
Pregunta 18
Pregunta
To produce signal in a spin echo pulse sequence, blood flow must receive
both the 90 degree and the 180 degree RF pulse.
Pregunta 19
Pregunta
Blood flow that receives a 90 degree excitation pulse but not a 180 degree
rephasing pulse produces what type of signal
Respuesta
-
High signal
-
Low signal
-
No signal
Pregunta 20
Pregunta
Blood flow that receives a 180 degree rephasing pulse but not a 90 degree
excitation pulse produces what type of signal
Respuesta
-
High signal
-
Low signal
-
No signal
Pregunta 21
Pregunta
The magnitude of time of flight phenomenon effects is dependent upon which
factor(s)
Respuesta
-
Velocity of flow
-
TE
-
Slice thickness
-
All of the above
Pregunta 22
Pregunta
As blood flow velocity increases, the effects of time of flight phenomenon
Respuesta
-
Increase
-
Decrease
-
Stays the same
Pregunta 23
Pregunta
As blood flow velocity decreases, the effects of time of flight phenomenon
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 24
Pregunta
As the echo time increases, the effects of time of flight phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 25
Pregunta
As echo time decreases, the effects of time offlight phenomenon
Respuesta
-
Increases
-
Decreases
-
Stays the same
Pregunta 26
Pregunta
As slice thickness increases, the effects of time of flight phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 27
Pregunta
As slice thickness decreases, the effects of time of flight phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 28
Pregunta
In a gradient echo pulse sequence, blood flow that receives the initial RF
pulse produces what type of signal
Pregunta 29
Pregunta
The flow phenomenon that is characterized by the contrast differences
between fresh flowing nuclei entering a slice and stationary tissue within
that slice is known as
Pregunta 30
Pregunta
Entry slice phenomenon is most prominent in what slice of the area scanned
Respuesta
-
First slice
-
Middle slice
-
Last slice
-
Affects all the same
Pregunta 31
Pregunta
The effects of entry slice phenomenon are dependent upon which factor(s)
Respuesta
-
Repetition time
-
Slice thickness
-
Velocity of flow
-
All of the above
Pregunta 32
Pregunta
When TR is decreased, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 33
Pregunta
When TR is increased, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 34
Pregunta
When slice thickness is increased, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 35
Pregunta
When slice thickness is decreased, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 36
Pregunta
When the velocity of flow increases, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 37
Pregunta
When the velocity of flow decreases, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 38
Pregunta
The direction of blood flow is an important factor in determining the effects
of entry slice phenomenon
Pregunta 39
Pregunta
Blood flow that travels in the same direction in which the slices are acquired
is known as what type of flow
Respuesta
-
Counter current flow
-
Vortex flow
-
Stagnant flow
-
Co-current flow
Pregunta 40
Pregunta
Blood flow that travels in the opposite direction in which the slices are
acquired is known as what type of flow
Respuesta
-
Counter current flow
-
Vortex flow
-
Stagnant flow
-
Co-current flow
Pregunta 41
Pregunta
When the direction of blood flow is opposite the direction in which slices are
acquired, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 42
Pregunta
When the direction of blood flow is the same as the direction in which slices
are acquired, the effects of entry slice phenomenon
Respuesta
-
Increase
-
Decrease
-
Stay the same
Pregunta 43
Pregunta
The flow phenomenon that is characterized by phase differences between
flowing and stationary nuclei within a voxel is known as
Pregunta 44
Pregunta
The magnitude of intra-voxel dephasing is dependent upon which factor(s)
Pregunta 45
Pregunta
In which of the following types of flow can intra-voxel dephasing be
compensated for
Respuesta
-
Turbulent flow
-
Vortex flow
-
Stagnant flow
-
Laminar flow
Pregunta 46
Pregunta
The use of an additional gradient to correct the effects of intra-voxel
dephasing is a technique known as
Respuesta
-
Gradient moment rephasing
-
Intra-voxel misregistration
-
Gradient moment nulling
-
Gradient moment rephasing & Gradient moment nulling
Pregunta 47
Pregunta
Gradient moment nulling is most effective on which type of flow
Respuesta
-
Slow turbulent flow
-
Fast laminar flow
-
Slow laminar flow
-
Fast vortex flow
Pregunta 48
Pregunta
The effects of time of flight and entry slice phenomena can be minimized by
which method
Respuesta
-
Gradient moment nulling
-
Pre-saturation RF pulse
-
Respiratory compensation
-
None of the above
Pregunta 49
Pregunta
The method of acquiring more than one echo that are multiples of each other
to reduce intra-voxel dephasing is known as
Respuesta
-
Gradient moment nulling
-
Pre-saturation RF pulse
-
Even echo rephasing
-
None of the above
Pregunta 50
Pregunta
Which of the following conventional MRI techniques can be used to produce
contrast differences between vascular structures and stationary structures
Pregunta 51
Pregunta
Which of the following is the conventional technique used to produce a black
appearance in vascular structures
Respuesta
-
Short TE, Short TR, Pre-saturation pulse
-
Long TE, Short TR, Gradient moment nulling
-
Long TE, Long TR, Respiratory compensation
-
None of the above
Pregunta 52
Pregunta
Which of the following is the conventional technique used to produce a
bright appearance in vascular structures
Respuesta
-
Pre-saturation pulse
-
Respiratory compensation
-
Gradient moment nulling
-
None of the above
Pregunta 53
Pregunta
The vascular imaging method that maximizes vascular contrast while also
suppressing stationary tissue is known as
Pregunta 54
Pregunta
Which of the following is a method used inMRAto suppress stationary
tissue
Pregunta 55
Pregunta
Which of the following is a method used in MRA to increase signal from
vascular structures
Pregunta 56
Pregunta
The type of MRA that uses gradient echo pulse sequences and gradient
moment nulling to enhance flow is known as
Respuesta
-
Digital subtraction
-
TOFMRA
-
PCMRA
-
Velocity encoding
Pregunta 57
Pregunta
In TOF MRA, which method is used to suppress signal from stationary
tissue?
Respuesta
-
Saturation
-
Subtraction
-
Gradient moment nulling
-
None of the above
Pregunta 58
Pregunta
TOF MRA is most sensitive to blood flow that flows in what direction in
relation to the slice
Pregunta 59
Pregunta
Which of the following is a disadvantage of TOF MRA
Respuesta
-
Parallel flow can be suppressed
-
Slow flow can be suppressed
-
Stationary tissue with short Tl relaxation times can produce signal
-
All of the above
Pregunta 60
Pregunta
Which of the following is an advantage of TOF MRA
Respuesta
-
Relatively short scan times
-
Increased sensitivity to flow
-
Decreased sensitivity to intra-voxel dephasing
-
All of the above
Pregunta 61
Pregunta
Which of the following TOF MRA sequences is most likely to saturate slow
flow
Pregunta 62
Pregunta
The type of MRA that produces image contrast based on the differences in
phase shifts between blood flow and stationary tissue is known as
Respuesta
-
TOFMRA
-
Velocity encoding
-
PCMRA
-
None ofthe above
Pregunta 63
Pregunta
Which of the following type of MRA uses a bipolar gradient to enhance
vascular structures
Respuesta
-
TOFMRA
-
Bright blood imaging
-
Phase contrast MRA
-
Black Blood imaging
Pregunta 64
Pregunta
Which of the following is a type of image that is produced by phase contrast
MRA?
Pregunta 65
Pregunta
Which of the following is an advantage of phase contrast MRA
Respuesta
-
Increased stationary tissue suppression
-
Sensitive to flow in all directions
-
Sensitive to flow with various velocities
-
All of the above
Pregunta 66
Pregunta
Which of the following is a disadvantage of phase contrast MRA
Respuesta
-
Long scan times
-
Reduced intra-voxel dephasing
-
Increased sensitivity to turbulence
-
Long scan times & Increased sensitivity to turbulence
Pregunta 67
Pregunta
Which of the following PC MRA techniques provides the highest signal to
noise ratio and spacial resolution
Pregunta 68
Pregunta
The method that is most commonly used to reduce artifact produced by
cardiac motion when scanning the chest is known as
Respuesta
-
Respiratory gating
-
Respiratory compensation
-
Cardiac gating
-
None of the above
Pregunta 69
Pregunta
Two types of cardiac gating that are most commonly used are known as
Respuesta
-
Respiratory gating, Respiratory compensation
-
ECG gating, Peripheral gating
-
Pseudo gating, Respiratory gating
-
None of the above
Pregunta 70
Pregunta
The P wave of the ECG represents which phase of the cardiac cycle
Respuesta
-
Atrial systole
-
Ventricular systole
-
Ventricular diastole
-
Atrial diastole
Pregunta 71
Pregunta
The QRS wave of the ECG represents which phase of the cardiac cycle?
Respuesta
-
Atrial systole
-
Ventricular systole
-
Ventricular diastole
-
Atrial diastole
Pregunta 72
Pregunta
The T wave of the ECG represents which phase of the cardiac cycle
Respuesta
-
Atrial systole
-
Ventricular systole
-
Ventricular diastole
-
Atrial diastole
Pregunta 73
Pregunta
During cardiac gating, which wave is used to trigger each pulse sequence
Respuesta
-
P wave
-
Q wave
-
R wave
-
T wave
Pregunta 74
Pregunta
During cardiac gating, the time between two consecutive R waves is known
as
Respuesta
-
Trigger window
-
Trigger delay
-
R-R interval
-
None of the above
Pregunta 75
Pregunta
The ECG wave with the highest electrical amplitude is known as the
Respuesta
-
R wave
-
Q wave
-
T wave
-
P wave
Pregunta 76
Pregunta
During cardiac gating, TR is dependent upon which factor(s)
Pregunta 77
Pregunta
During cardiac gating, which factors are affected by having an effective TR
Respuesta
-
Image weighting
-
Number of slices
-
Scan time
-
All of the above
Pregunta 78
Pregunta
During cardiac gating, the waiting time between the R wave and the start of
the data acquisition is known as
Respuesta
-
Repetition time
-
Inversion time
-
Trigger delay
-
Echo delay
Pregunta 79
Pregunta
During cardiac gating, the waiting time before each R wave is known as
Respuesta
-
Repetition time
-
Inversion time
-
Trigger delay
-
Trigger window
Pregunta 80
Pregunta
During cardiac gating, which of the following is the formula used to calculate
available imaging time
Pregunta 81
Pregunta
The type of cardiac gating that detects the increase in blood volume in the
capillary bed during systole is known as
Respuesta
-
ECG gating
-
Pseudo gating
-
Peripheral gating
-
None of the above
Pregunta 82
Pregunta
During cardiac gating, one R-R interval and a short TE is used to produce
what type of image
Respuesta
-
T1 weighting
-
T2 weighting
-
Proton density weighting
-
None of the above