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