MRI Physics Final Exam Study Set3| 230+
Questions and 100% Correct Answers
Using a fast spin echo pulse sequence - ✔✔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 - ✔✔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 - ✔✔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 - ✔✔If a flowing nucleus is adjacent to a stationary nucleus in a voxel, there is a
__________ difference between the two nuclei.
Extra-voxel dephasing - ✔✔The causes of flow artifacts are known as flow phenomena. The
principle phenomena are all of the following except:
TOF
Intra-voxel dephasing
Extra-voxel dephasing
Entry slice phenomena
,Scan TR divided by number of slices - ✔✔The SAT TR is equal to?
Entry-slice phenomena - ✔✔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 - ✔✔The four principle types of flow are all of the following except:
Exited - ✔✔As TE increases, a higher proportion of flowing nuclei have ________ the slice
between the excitation pulse and rephasing pulse.
False - ✔✔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 - ✔✔True or False:
Spatial pre-saturation nullifies the signal from flowing nuclei so the effects of entry slice and
TOF phenomena are minimized.
False - ✔✔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.
Transverse, inferior to the region of interest - ✔✔In what orientation and position, should a
saturation reign be located in order to eliminate carotid flow from transverse images of the
cervical spine?
,Y gradient - ✔✔If a coronal saturation reigon is placed anterior to the cervical spine to
eliminate motion artifacts from swallowing, which gradient must be turned on during the
transmission of the initial saturation 90 degree RF pulse?
Lower chance of inaccuracy on image - ✔✔All of the following describe, or are consequences
of turbulent flow except:
Great deal of dephasing in this locations
Lower chance of inaccuracy on image
Mixing and moving in more than one direction
Found in tortuous sections, distal to bifurcations and stenosis
Phase Matrix - ✔✔All of the following affect entry slice phenomena except:
Direction of flow
Slice thickness
Velocity of flow
TR
Phase Matrix
Increases - ✔✔As velocity of flow increases, the time of flight effect:
False - ✔✔True or False:
To reduce truncation artifact, decrease phase encoding steps from 256 to 128.
Chemical mis-registation - ✔✔What produces a ring of dark signal around certain organs
where fat and water interfaces occur within same voxel?
, 62.5 Hz - ✔✔If the receive bandwidth = 16 KHz, and if 256 is the frequency matrix, what is
the frequency range of each pixel?
Swapping phase and frequency - ✔✔To reduce phase misshaping, the direction of the phase
encoding gradient can be changed to get rid of the artifact interfacing with the area of interest.
This is known as:
True - ✔✔True or False:
To reduce shading artifact, ensure that the coil is loaded correctly, and the PT is not touching
the coil at any point.
Respiratory Ordered Phase Encoding - ✔✔ROPE is a respiratory compensation method.
What does ROPE stand for?
True - ✔✔True or False:
Phase mipmapping is caused by anatomy moving along the encoding gradient during the pulse
sequence.
3.5 - ✔✔The chemical shift between fat and water has been measured to be approximately
______ parts per million (ppm).
True - ✔✔True or False:
Aliasing or wrap around produces images where anatomy that exists outside the FOV is folded
onto the top of the anatomy inside the FOV.
Oversampling
Increase FOV
PreSat Band - ✔✔Which of the following are ways to prevent phase wrap artifact? (select all
that apply):
Questions and 100% Correct Answers
Using a fast spin echo pulse sequence - ✔✔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 - ✔✔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 - ✔✔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 - ✔✔If a flowing nucleus is adjacent to a stationary nucleus in a voxel, there is a
__________ difference between the two nuclei.
Extra-voxel dephasing - ✔✔The causes of flow artifacts are known as flow phenomena. The
principle phenomena are all of the following except:
TOF
Intra-voxel dephasing
Extra-voxel dephasing
Entry slice phenomena
,Scan TR divided by number of slices - ✔✔The SAT TR is equal to?
Entry-slice phenomena - ✔✔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 - ✔✔The four principle types of flow are all of the following except:
Exited - ✔✔As TE increases, a higher proportion of flowing nuclei have ________ the slice
between the excitation pulse and rephasing pulse.
False - ✔✔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 - ✔✔True or False:
Spatial pre-saturation nullifies the signal from flowing nuclei so the effects of entry slice and
TOF phenomena are minimized.
False - ✔✔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.
Transverse, inferior to the region of interest - ✔✔In what orientation and position, should a
saturation reign be located in order to eliminate carotid flow from transverse images of the
cervical spine?
,Y gradient - ✔✔If a coronal saturation reigon is placed anterior to the cervical spine to
eliminate motion artifacts from swallowing, which gradient must be turned on during the
transmission of the initial saturation 90 degree RF pulse?
Lower chance of inaccuracy on image - ✔✔All of the following describe, or are consequences
of turbulent flow except:
Great deal of dephasing in this locations
Lower chance of inaccuracy on image
Mixing and moving in more than one direction
Found in tortuous sections, distal to bifurcations and stenosis
Phase Matrix - ✔✔All of the following affect entry slice phenomena except:
Direction of flow
Slice thickness
Velocity of flow
TR
Phase Matrix
Increases - ✔✔As velocity of flow increases, the time of flight effect:
False - ✔✔True or False:
To reduce truncation artifact, decrease phase encoding steps from 256 to 128.
Chemical mis-registation - ✔✔What produces a ring of dark signal around certain organs
where fat and water interfaces occur within same voxel?
, 62.5 Hz - ✔✔If the receive bandwidth = 16 KHz, and if 256 is the frequency matrix, what is
the frequency range of each pixel?
Swapping phase and frequency - ✔✔To reduce phase misshaping, the direction of the phase
encoding gradient can be changed to get rid of the artifact interfacing with the area of interest.
This is known as:
True - ✔✔True or False:
To reduce shading artifact, ensure that the coil is loaded correctly, and the PT is not touching
the coil at any point.
Respiratory Ordered Phase Encoding - ✔✔ROPE is a respiratory compensation method.
What does ROPE stand for?
True - ✔✔True or False:
Phase mipmapping is caused by anatomy moving along the encoding gradient during the pulse
sequence.
3.5 - ✔✔The chemical shift between fat and water has been measured to be approximately
______ parts per million (ppm).
True - ✔✔True or False:
Aliasing or wrap around produces images where anatomy that exists outside the FOV is folded
onto the top of the anatomy inside the FOV.
Oversampling
Increase FOV
PreSat Band - ✔✔Which of the following are ways to prevent phase wrap artifact? (select all
that apply):
