MRI Registry Special Procedures
EXAM VERIFIED | LATEST UPDATE A+
SOLUTION GUIDE
A method of visualizing vessels (arteries or veins) that contain flowing nuclei, by
creating a contrast between them and stationary non-flowing nuclei. - Answer- Magnetic
Resonance Angiography (MRA)
This subject requires an understanding of both flow mechanics and flow phenomena -
Answer- Flow dynamics
What are the four types of flow mechanics? - Answer- 1. Laminar flow.
2. Spiral flow.
3. Vortex flow.
4. Turbulent flow
What is laminar flow also referred to as? - Answer- 1st order of motion
This type of flow is described as normal blood flow that because it has a constant
velocity - Answer- Laminar flow
The type of flow that describes the spiral motion of blood as it nears an occlusion -
Answer- Spiral flow
The type of flow that describes the spiral motion of blood as it passes through an
occlusion - Answer- Vortex flow
What is turbulent flow also referred to as - Answer- 3rd order motion
This type of flow is described as the random fluctuation of blood flow after passing
through an occlusion - Answer- Turbulent flow
The phenomenon that explains how stationary spins always receive both the excitation
and rephasing pulse, and flowing spins present within the slice for excitation have
usually traveled out of the slice before being rephased (thus returning no signal). -
Answer- Time of flight
Time of flight phenomenon is only observable during __________ sequences. - Answer-
SE
During _________ sequences, all spins (stationary and flowing) throughout the entire
imaging volume get rephased because the rephasing gradient used is not slice
selective. - Answer- GE
, The following are multiple factors that affect the amount of time of flight (TOF) affect
present during SE sequences: - Answer- 1. Velocity of flow.
2. Entry slice phenomenon.
3. Intra-voxel Dephasing
As flow velocity increases, ___________ flowing nuclei are present within the slice for
both the excitation and rephasing pulse. - Answer- Less
As flow velocity decreases, ___________ flowing nuclei are present within the slice for
both the excitation and rephasing pulse, thus TOF effects _______________. - Answer-
More; decrease
Velocity of flow: as the TE increases, ____________ flowing newly exit the slice
between the excitation pulse and the rephasing pulse, thus giving a ____________ in
signal that ________________ TOF effect - Answer- More; decrease; increases
As slice thickness increases, ____________ flowing nuclei receive both the excitation
and rephasing pulse since they travel through the slice longer, thus ________________
signal, which resulting in a________________ of TOF effects. - Answer- More;
increasing; decrease
What is entry slice phenomenon, also known as? - Answer- Inflow effect
This phenomenon explains how spins flowing perpendicular to a stack of slices Enter
the stack fresh (unsaturated) and produce more signal than stationary nuclei that
receive repeated RF excitation (saturated). - Answer- Entry slice phenomenon
As the flowing nuclei travel deeper into the stack, they receive more and more RF
excitation, dust becoming saturated, which results in a? - Answer- Decrease of entry
slice phenomenon
The following are multiple factors that affect the amount of entry/phenomenon present in
a stack of slices: - Answer- 1. TR
2. Slice thickness.
3. Velocity of flow.
4. Direction of flow.
As TR increases, less RF excitation pulses get delivered to tissues overtime. Thus,
entry slice phenomenon ________________ because more unsaturated flowing spins
are present. - Answer- Increases
As sliced thickness increases, flowing nuclei tend to receive more RF excitation pulses.
Thus, entry slice phenomenon _______________ due to the longer time required for
spins to travel across a slice. - Answer- Decreases
EXAM VERIFIED | LATEST UPDATE A+
SOLUTION GUIDE
A method of visualizing vessels (arteries or veins) that contain flowing nuclei, by
creating a contrast between them and stationary non-flowing nuclei. - Answer- Magnetic
Resonance Angiography (MRA)
This subject requires an understanding of both flow mechanics and flow phenomena -
Answer- Flow dynamics
What are the four types of flow mechanics? - Answer- 1. Laminar flow.
2. Spiral flow.
3. Vortex flow.
4. Turbulent flow
What is laminar flow also referred to as? - Answer- 1st order of motion
This type of flow is described as normal blood flow that because it has a constant
velocity - Answer- Laminar flow
The type of flow that describes the spiral motion of blood as it nears an occlusion -
Answer- Spiral flow
The type of flow that describes the spiral motion of blood as it passes through an
occlusion - Answer- Vortex flow
What is turbulent flow also referred to as - Answer- 3rd order motion
This type of flow is described as the random fluctuation of blood flow after passing
through an occlusion - Answer- Turbulent flow
The phenomenon that explains how stationary spins always receive both the excitation
and rephasing pulse, and flowing spins present within the slice for excitation have
usually traveled out of the slice before being rephased (thus returning no signal). -
Answer- Time of flight
Time of flight phenomenon is only observable during __________ sequences. - Answer-
SE
During _________ sequences, all spins (stationary and flowing) throughout the entire
imaging volume get rephased because the rephasing gradient used is not slice
selective. - Answer- GE
, The following are multiple factors that affect the amount of time of flight (TOF) affect
present during SE sequences: - Answer- 1. Velocity of flow.
2. Entry slice phenomenon.
3. Intra-voxel Dephasing
As flow velocity increases, ___________ flowing nuclei are present within the slice for
both the excitation and rephasing pulse. - Answer- Less
As flow velocity decreases, ___________ flowing nuclei are present within the slice for
both the excitation and rephasing pulse, thus TOF effects _______________. - Answer-
More; decrease
Velocity of flow: as the TE increases, ____________ flowing newly exit the slice
between the excitation pulse and the rephasing pulse, thus giving a ____________ in
signal that ________________ TOF effect - Answer- More; decrease; increases
As slice thickness increases, ____________ flowing nuclei receive both the excitation
and rephasing pulse since they travel through the slice longer, thus ________________
signal, which resulting in a________________ of TOF effects. - Answer- More;
increasing; decrease
What is entry slice phenomenon, also known as? - Answer- Inflow effect
This phenomenon explains how spins flowing perpendicular to a stack of slices Enter
the stack fresh (unsaturated) and produce more signal than stationary nuclei that
receive repeated RF excitation (saturated). - Answer- Entry slice phenomenon
As the flowing nuclei travel deeper into the stack, they receive more and more RF
excitation, dust becoming saturated, which results in a? - Answer- Decrease of entry
slice phenomenon
The following are multiple factors that affect the amount of entry/phenomenon present in
a stack of slices: - Answer- 1. TR
2. Slice thickness.
3. Velocity of flow.
4. Direction of flow.
As TR increases, less RF excitation pulses get delivered to tissues overtime. Thus,
entry slice phenomenon ________________ because more unsaturated flowing spins
are present. - Answer- Increases
As sliced thickness increases, flowing nuclei tend to receive more RF excitation pulses.
Thus, entry slice phenomenon _______________ due to the longer time required for
spins to travel across a slice. - Answer- Decreases
