MRI PHYSICS 2 FINAL EXAM WITH COMPLETE
SOLUTIONS
Gradient Echo Correct Ans-In regards to MRI and flowing blood, all of the following
naturally offer dark blood without any special imaging requirements, except which?
Gradient Echo
Fast Spin Echo
Spin Echo
Inversion Recovery
False Correct Ans-True or False:
Gradient moment nulling predominantly increases intra-voxel dephasing?
Time of Flight phenomena Correct Ans-If flowing nuclei receive a 90 degree (excitation) but
do not receive a 180 degree (rephasing) pulse, no echo will be produced. This is known as?
Co-current Correct Ans-Flow that is in the same direction as slice selection is called?
High Correct Ans-Fat or water saturation is most effective on ______ field systems.
,Gradient moment nulling Correct Ans-____________ is when flowing spins gains 90 degree
phase as it passes the first positive lobe of gradient, then loses 180 degree as it passes through the
double negative lobe of gradient, then passes through the last positive lobe of gradient.
Large Correct Ans-To saturate or null fat or water, the precessional difference between the
two must sufficiently ________ so that they can be isolated from each other.
Velocity of flow decreases
TE decrease
Slice thickness increases Correct Ans-Flow related enhancement increases as the: (select all
that apply)
False Correct Ans-True or False:
For a constant velocity, nuclei take longer to travel through a thin slice compared with a thick
slice.
Decrease Correct Ans-A pulse sequence with a given set of parameters allows a maximum of
20 slices. If 2 saturation pulses are added, one would expect the maximum number of slices to:
Fat saturation Correct Ans-Which of the following techniques would be ineffective at
reducing motion artifacts created by blood flowing through the sagittal sinus?
,Chemical pre saturation Correct Ans-A method in which the specific frequency of just fat, or
water, is transmitted to push just those protons into transverse magnetization prior to the 90
degree RF pulse is known as what?
First Correct Ans-Entry slice phenomena (inflow effect) is most prominent in ________ slice
of "stack" of slices.
True Correct Ans-True or False:
Turbulent flow is flow at different velocities that fluctuates randomly?
Opposite Correct Ans-Counter-current flow has flowing nuclei traveling in __________
direction to slice excitation.
2.2 Correct Ans-Out of phase TE at 1.5T is approximately?
147 Hz Correct Ans-The precessional frequency difference of fat and water at 1.0T is?
Decreases Correct Ans-Entry slice phenomena _________ if nuclei receive repeated
excitations.
TE
Velocity of flow
Slice thickness Correct Ans-TOF effects depend on the following: (select all that apply)
, TR
Slice thickness
Velocity of flow
Direction of flow Correct Ans-Magnitude of entry slice phenomena depends on the
following: (select all that apply)
At the first slice in the stack
When using a long TR
In thin slices Correct Ans-Entry slice phenomena increases: (select all that apply)
Using a fast spin echo pulse sequence Correct Ans-All of the following are ways of
compensating for flow phenomena except:
Gradient Moment Nulling
Even Echo Rephasing
Spatial Presaturation
Using a fast spin echo pulse sequence
True Correct Ans-True or False:
Vortex flow is flow that is initially laminar but then passes through a stricture or stenosis in the
vessel?
SOLUTIONS
Gradient Echo Correct Ans-In regards to MRI and flowing blood, all of the following
naturally offer dark blood without any special imaging requirements, except which?
Gradient Echo
Fast Spin Echo
Spin Echo
Inversion Recovery
False Correct Ans-True or False:
Gradient moment nulling predominantly increases intra-voxel dephasing?
Time of Flight phenomena Correct Ans-If flowing nuclei receive a 90 degree (excitation) but
do not receive a 180 degree (rephasing) pulse, no echo will be produced. This is known as?
Co-current Correct Ans-Flow that is in the same direction as slice selection is called?
High Correct Ans-Fat or water saturation is most effective on ______ field systems.
,Gradient moment nulling Correct Ans-____________ is when flowing spins gains 90 degree
phase as it passes the first positive lobe of gradient, then loses 180 degree as it passes through the
double negative lobe of gradient, then passes through the last positive lobe of gradient.
Large Correct Ans-To saturate or null fat or water, the precessional difference between the
two must sufficiently ________ so that they can be isolated from each other.
Velocity of flow decreases
TE decrease
Slice thickness increases Correct Ans-Flow related enhancement increases as the: (select all
that apply)
False Correct Ans-True or False:
For a constant velocity, nuclei take longer to travel through a thin slice compared with a thick
slice.
Decrease Correct Ans-A pulse sequence with a given set of parameters allows a maximum of
20 slices. If 2 saturation pulses are added, one would expect the maximum number of slices to:
Fat saturation Correct Ans-Which of the following techniques would be ineffective at
reducing motion artifacts created by blood flowing through the sagittal sinus?
,Chemical pre saturation Correct Ans-A method in which the specific frequency of just fat, or
water, is transmitted to push just those protons into transverse magnetization prior to the 90
degree RF pulse is known as what?
First Correct Ans-Entry slice phenomena (inflow effect) is most prominent in ________ slice
of "stack" of slices.
True Correct Ans-True or False:
Turbulent flow is flow at different velocities that fluctuates randomly?
Opposite Correct Ans-Counter-current flow has flowing nuclei traveling in __________
direction to slice excitation.
2.2 Correct Ans-Out of phase TE at 1.5T is approximately?
147 Hz Correct Ans-The precessional frequency difference of fat and water at 1.0T is?
Decreases Correct Ans-Entry slice phenomena _________ if nuclei receive repeated
excitations.
TE
Velocity of flow
Slice thickness Correct Ans-TOF effects depend on the following: (select all that apply)
, TR
Slice thickness
Velocity of flow
Direction of flow Correct Ans-Magnitude of entry slice phenomena depends on the
following: (select all that apply)
At the first slice in the stack
When using a long TR
In thin slices Correct Ans-Entry slice phenomena increases: (select all that apply)
Using a fast spin echo pulse sequence Correct Ans-All of the following are ways of
compensating for flow phenomena except:
Gradient Moment Nulling
Even Echo Rephasing
Spatial Presaturation
Using a fast spin echo pulse sequence
True Correct Ans-True or False:
Vortex flow is flow that is initially laminar but then passes through a stricture or stenosis in the
vessel?
