MRI PHYSICS 2 FINAL Exam 2024/2025(Questions With 100% Correct Answers)A+ Graded Verified
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Course
MRI PHYSICS 2
Institution
MRI PHYSICS 2
Gradient Echo - ANSWER 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 - ANSWER True or False:
Gradient moment nulling pre...
MRI PHYSICS 2 FINAL Exam 2024/2025(Questions With
100% Correct Answers)A+ Graded Verified
Gradient Echo - ANSWER 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 - ANSWER True or False:
Gradient moment nulling predominantly increases intra-voxel dephasing?
Time of Flight phenomena - ANSWER 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 - ANSWER Flow that is in the same direction as slice selection is called?
High - ANSWER Fat or water saturation is most effective on ______ field systems.
Gradient moment nulling - ANSWER ____________ 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 - ANSWER 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 - ANSWER Flow related enhancement increases as the:
(select all that apply)
False - ANSWER True or False:
For a constant velocity, nuclei take longer to travel through a thin slice compared with a
thick slice.
Decrease - ANSWER 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 - ANSWER Which of the following techniques would be ineffective at
reducing motion artifacts created by blood flowing through the sagittal sinus?
Chemical pre saturation - ANSWER 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 - ANSWER Entry slice phenomena (inflow effect) is most prominent in ________
slice of "stack" of slices.
True - ANSWER True or False:
Turbulent flow is flow at different velocities that fluctuates randomly?
Opposite - ANSWER Counter-current flow has flowing nuclei traveling in __________
direction to slice excitation.
2.2 - ANSWER Out of phase TE at 1.5T is approximately?
147 Hz - ANSWER The precessional frequency difference of fat and water at 1.0T is?
TE
Velocity of flow
Slice thickness - ANSWER TOF effects depend on the following: (select all that apply)
TR
Slice thickness
Velocity of flow
Direction of flow - ANSWER 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 - ANSWER Entry slice phenomena increases: (select all that apply)
Using a fast spin echo pulse sequence - ANSWER 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 - ANSWER True or False:
Vortex flow is flow that is initially laminar but then passes through a stricture or stenosis
in the vessel?
Even echo rephasing - ANSWER If there is two or more echoes produced in a fast spin
echo pulse sequence, intravoxel dephasing may be reduced by acquiring the second and
succeeding even echoes at multiple of the first TE. This is known as:
Phase - ANSWER If a flowing nucleus is adjacent to a stationary nucleus in a voxel,
there is a __________ difference between the two nuclei.
Extra-voxel dephasing - ANSWER The causes of flow artifacts are known as flow
phenomena. The principle phenomena are all of the following except:
Scan TR divided by number of slices - ANSWER The SAT TR is equal to?
Entry-slice phenomena - ANSWER The phenomena that occurs when moving protons,
usually when moving perpendicular to the slice plane, appear brighter in the first slice
than the rest of the slices is known as what?
Circular flow - ANSWER The four principle types of flow are all of the following except:
Exited - ANSWER As TE increases, a higher proportion of flowing nuclei have
________ the slice between the excitation pulse and rephasing pulse.
False - ANSWER True or False:
Co-current flow, in regards to entry slice phenomen, is when the moving protons are
traveling in the opposite direction of the slice direction, thus making entry slice
phenomena less pronounced.
True - ANSWER True or False:
Spatial pre-saturation nullifies the signal from flowing nuclei so the effects of entry slice
and TOF phenomena are minimized.
False - ANSWER True or False:
Second order motion can be compensated for as system can only correct for flow that is
at constant velocity and direction during data acquisition.
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