ARRT MRI FULL QUESTIONS AND CORRECT ANSWERS
ALREADY PASSED 2025 LATEST UPDATE.
✅to achieve low phase matrix the phase encoding gradient is applied _____ times during the
pulse sequence. Answer:fewer
✅the ______ slope of the phase encoding gradient, either positive or negative, determines
pixel size in the phase encoding direction of the image. Answer:steepest
✅to achieve a small pixel a _______ PEG is used. Answer:steep
✅to achieve a big pixel a _______ PEG is used. Answer:shallow
✅describe the gradients that are turned on in a pulse sequence in order. Answer:1) slice
select during RF excitation pulse
2) phase encoding gradient
3) if SE the slice select again with the 180 rephasing pulse
4) frequency encoding gradient centered over peak of echo
✅what is fast fourier transform?. Answer:math that gets frequencies in the echo to the
image,
✅what is k space. Answer:spatial frequency domain, where info is stored about the
frequency of a signal and where it comes from
✅every parameter we set changes how k space is filled with ____. Answer:data
,✅cartesian filling. Answer:Simplest method of filling. K-space is filled in a linear manner
from top to bottom or bottom to top
✅every TR the _________ amplitude is gradually decreased to step down through the lines of
k space until the center line is filled, then switched negatively to fill bottom half. Answer:PEG
✅analog to digital conversion. Answer:a process converting a waveform into binary
numbers, done inside the receiver coil assembly or the body of the MRI scanner
✅if the frequency matrix is 256 then ______ data points are acquired during the sampling
window. Answer:256
✅every _____ a different line of k space is filled with the same number of data points
determined by the frequency matrix. Answer:TR
✅the number of data points horizontally in each line equals ____. Answer:frequency matrix
✅the number of data points vertically in each column corresponds to the ______.
Answer:phase matrix
✅describe what the sampling window is. Answer:where the system measures spatial
frequencies in the echo
how long the frequency encoding gradient is on for
✅nyquist theorem. Answer:states that a frequency must be sampled at least twice in order
to reproduce it reliably
✅the digital sampling frequency is kept at what value?. Answer:twice the highest frequency
so as to avoid aliasing while still sampling in the most time efficient manner
✅to achieve high phase matrix the phase encoding gradient is applied _____ times during
the pulse sequence. Answer:many
,✅what parameter has the same numerical value as the digital sampling frequency?.
Answer:receiver bandwidth
✅the receiver bandwidth determines the _______________ accurately digitized during the
sampling window (same # as digital sampling frequency). Answer:range of frequencies
✅digital sampling frequency determines the _____________ acquired per second through
ADC. Answer:number of data points
✅the frequency matrix determines the number of data points collected during the ________.
Answer:sampling window
✅the _________ is affected by the duration of the sampling window because the echo is
usually centered in the middle of this window. Answer:minimum TE
✅even though the number of data points in each row and column of k space correspond to
the number of pixels, the grid of k space ______ correspond to the grid of pixels in the image.
Answer:does not
✅conjugate symmetry. Answer:k space symmetry top to bottom and left to right, because
the echo is centered and so the slope remains the same and each data point in k space is the
same as the one diagonally opposite
✅the central lines of k space are filled using a ____ slope gradient. Answer:shallow
✅shallow gradient slopes have. Answer:greater signal amplitude and are used for contrast
and signal
✅steeper gradient slopes have. Answer:greater phase shift and are used for resolution
✅the central portion of k space contains data that has. Answer:high signal amplitude and
low resolution
, ✅the outer portion of k space contains data that has. Answer:low signal amplitude and high
resolution
✅pixel size formula. Answer:FOV/matrix
✅the phase matrix depends on how many ___ of k space are filled with data points.
Answer:lines
✅the frequency matrix is the number of data points in each ____ of k space. Answer:row
✅partial, fractional averaging, or half fourier k space filling technique. Answer:where 75% of
the lines of k space is filled, zeroes are placed in the empty lines
✅partial echo k space filling technique. Answer:only part of the echo is read during the
application of FEG, usually dephasing portion due to extremely short TEs, and then the data
is mirrored to fill in the rest of k space, overall no data are lost, maximizes T1 and PD
✅parallel imaging k space filling technique. Answer:fills multiple lines of k space per TR,
using an array coils
✅single shot k space filling technique. Answer:collects all data from a single echo train,
switches gradients quickly, called phase blipping, there is no TR because there is only one RF
pulse (TR is infinity!)
✅spiral k space filling technique. Answer:PEG switch rapidly and oscillate, where filling
begins at the center and spirals out, no TR, all k space is filled in one shot
✅propeller or radial k space filling. Answer:Data points are acquired in strips and rotate
around the central axis. Reduces motion artifacts but scan time is increased.
✅sequential acquisitions k space. Answer:all the data from 1 slice and then all the data from
the next slice
ALREADY PASSED 2025 LATEST UPDATE.
✅to achieve low phase matrix the phase encoding gradient is applied _____ times during the
pulse sequence. Answer:fewer
✅the ______ slope of the phase encoding gradient, either positive or negative, determines
pixel size in the phase encoding direction of the image. Answer:steepest
✅to achieve a small pixel a _______ PEG is used. Answer:steep
✅to achieve a big pixel a _______ PEG is used. Answer:shallow
✅describe the gradients that are turned on in a pulse sequence in order. Answer:1) slice
select during RF excitation pulse
2) phase encoding gradient
3) if SE the slice select again with the 180 rephasing pulse
4) frequency encoding gradient centered over peak of echo
✅what is fast fourier transform?. Answer:math that gets frequencies in the echo to the
image,
✅what is k space. Answer:spatial frequency domain, where info is stored about the
frequency of a signal and where it comes from
✅every parameter we set changes how k space is filled with ____. Answer:data
,✅cartesian filling. Answer:Simplest method of filling. K-space is filled in a linear manner
from top to bottom or bottom to top
✅every TR the _________ amplitude is gradually decreased to step down through the lines of
k space until the center line is filled, then switched negatively to fill bottom half. Answer:PEG
✅analog to digital conversion. Answer:a process converting a waveform into binary
numbers, done inside the receiver coil assembly or the body of the MRI scanner
✅if the frequency matrix is 256 then ______ data points are acquired during the sampling
window. Answer:256
✅every _____ a different line of k space is filled with the same number of data points
determined by the frequency matrix. Answer:TR
✅the number of data points horizontally in each line equals ____. Answer:frequency matrix
✅the number of data points vertically in each column corresponds to the ______.
Answer:phase matrix
✅describe what the sampling window is. Answer:where the system measures spatial
frequencies in the echo
how long the frequency encoding gradient is on for
✅nyquist theorem. Answer:states that a frequency must be sampled at least twice in order
to reproduce it reliably
✅the digital sampling frequency is kept at what value?. Answer:twice the highest frequency
so as to avoid aliasing while still sampling in the most time efficient manner
✅to achieve high phase matrix the phase encoding gradient is applied _____ times during
the pulse sequence. Answer:many
,✅what parameter has the same numerical value as the digital sampling frequency?.
Answer:receiver bandwidth
✅the receiver bandwidth determines the _______________ accurately digitized during the
sampling window (same # as digital sampling frequency). Answer:range of frequencies
✅digital sampling frequency determines the _____________ acquired per second through
ADC. Answer:number of data points
✅the frequency matrix determines the number of data points collected during the ________.
Answer:sampling window
✅the _________ is affected by the duration of the sampling window because the echo is
usually centered in the middle of this window. Answer:minimum TE
✅even though the number of data points in each row and column of k space correspond to
the number of pixels, the grid of k space ______ correspond to the grid of pixels in the image.
Answer:does not
✅conjugate symmetry. Answer:k space symmetry top to bottom and left to right, because
the echo is centered and so the slope remains the same and each data point in k space is the
same as the one diagonally opposite
✅the central lines of k space are filled using a ____ slope gradient. Answer:shallow
✅shallow gradient slopes have. Answer:greater signal amplitude and are used for contrast
and signal
✅steeper gradient slopes have. Answer:greater phase shift and are used for resolution
✅the central portion of k space contains data that has. Answer:high signal amplitude and
low resolution
, ✅the outer portion of k space contains data that has. Answer:low signal amplitude and high
resolution
✅pixel size formula. Answer:FOV/matrix
✅the phase matrix depends on how many ___ of k space are filled with data points.
Answer:lines
✅the frequency matrix is the number of data points in each ____ of k space. Answer:row
✅partial, fractional averaging, or half fourier k space filling technique. Answer:where 75% of
the lines of k space is filled, zeroes are placed in the empty lines
✅partial echo k space filling technique. Answer:only part of the echo is read during the
application of FEG, usually dephasing portion due to extremely short TEs, and then the data
is mirrored to fill in the rest of k space, overall no data are lost, maximizes T1 and PD
✅parallel imaging k space filling technique. Answer:fills multiple lines of k space per TR,
using an array coils
✅single shot k space filling technique. Answer:collects all data from a single echo train,
switches gradients quickly, called phase blipping, there is no TR because there is only one RF
pulse (TR is infinity!)
✅spiral k space filling technique. Answer:PEG switch rapidly and oscillate, where filling
begins at the center and spirals out, no TR, all k space is filled in one shot
✅propeller or radial k space filling. Answer:Data points are acquired in strips and rotate
around the central axis. Reduces motion artifacts but scan time is increased.
✅sequential acquisitions k space. Answer:all the data from 1 slice and then all the data from
the next slice
