ASMIRT - MRI ACCREDITATION EXAM ACTUAL
EXAM 2026 || MOST RECENT EXAM 2026|2027 ACTUAL
COMPLETE REAL EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) ALREADY GRADED
A+ | GUARANTEED SUCCESS!! NEWEST EXAM | JUST
RELEASED!!
What is cross-talk artefact? - ANSWER-This refers to the
interference which occurs between adjacent slices and is due
to the imperfect nature of RF pulses. Ideally, each RF pulse
would have a rectangular profile supplying maximum amplitude
at the desired frequencies and zero amplitude above or below.
Unfortunately, this is not possible and RF pulse profiles have a
curved component. Whenever a slice is excited there will
always be some excitation of tissue on either side. This can
produce saturation effects with an associated loss of signal
intensity
How can cross-talk artefact be remedied? - ANSWER-Remedies
include: • inter-slice gaps • interleaving within the same TR •
interleaving with separate acquisition for odd and even slices
(which doubles the time)
What is zipper artefact? - ANSWER-The Zipper artefact is
caused by RF breakthrough and is probably the most common
equipment artefact. This appears as a zipper like band of light
and dark pixels passing through the image. It is often two to
three pixels wide and extending across an image in the phase
,encoding direction. It is usually caused by extraneous RF
getting into the examination through some disruption to the RF
shielding - eg. a partially open
door or a conductive cable passed through a wave-guide. This
RF is picked up
by the receive coils and mapped into the image. Another
common cause is RF
emission is from equipment within the examination room
such as a pulse
oximeter.
What are reconstruction artefacts? - ANSWER-The Zipper
artefact is caused by RF breakthrough and is probably the most
common equipment artefact. This appears as a zipper like band
of light and dark pixels passing through the image. It is often
two to three pixels wide and extending across an image in the
phase encoding direction. It is usually caused by extraneous
RF getting into the examination through some disruption to the
RF shielding - eg. a partially open door or a conductive cable
passed through a wave-guide. This RF is picked up by the
receive coils and mapped into the image. Another common
cause is RF emission is from equipment within the examination
room such as a pulse oximeter.
What can certain artefacts indicate in terms of machine
malfunction? -
ANSWER-MRI systems are complex and breakdowns in various
components do happen. The resultant images can be
particularly strange. There appearance however can often help
,in identifying the problem. A skewing of the entire image can be
an indication of a malfunctioning gradient coil or amplifier.
Sometimes although rarely this is also due to the loss of a shim
coil. Reduced intensity or shading through an entire image is
often the result of a failure in the transmit or receive RF chain.
What is MRA? - ANSWER-Magnetic Resonance angiography
(MRA) uses the inherent motion sensitivity of MRI to visualize
blood flow from within vessels. The moving spins in MRI such
as flowing blood have a significant effect on the final signal.
These effects can be image degrading such as artefacts.
However they can also be useful to produce MR angiograms.
The first effect of blood flow is its movement through slices.
The TOF effect arises because some or all of the blood within
an imaged slice is replaced during the repetition time or
between the application of the 90 degree and 180 degree pulses
TE/2.
What are the two main types of MRA? - ANSWER-TOF - Time
of Flight: relies
on flow dependent changes in longitudinal
magnetization.
PC - Phase Contrast: relies on flow dependent changes
in transverse
magnetization.
What signal will blood give if it is "stationary" in a SE MRA? -
ANSWER-If blood is "stationary" the spins will experience both
the 90 degree and 180 degree pulse generating an echo. Now
, whilst blood is never truly stationary unless your patient is
"dead" the signal returned from it is dependent on the blood
velocity and the slice thickness. Thus if we have a thick slice,
slow flowing blood may appear to be "stationary" and thus give
us a signal.
What signal will be returned by blood with a high velocity in a
SE MRA? - ANSWER-When the blood velocity reaches the point
where the blood within a slice has completely left in the time
between the 90 degree and 180 degree pulses then no signal is
returned. This is known as high velocity signal loss or wash
out.
What is occurring in blood that returns an intermediate signal
in a SE MRA? - ANSWER-The third type of signal behavior
occurs at an intermediate stage compared to the above two
examples. This occurs when blood is moving at a speed such
that only some of the blood leaves between the two excitation
pulses. The portion that remains is diluted by fresh blood
flowing into the slice. Only the blood that remains in the slice
receiving both pulses will produce a signal. This results in a
reduction of signal due to the wash out effect.
What are the signal differences of stationary and high velocity
blood in a GE
MRA compared to a SE MRA? - ANSWER-Gradient echo images
are different due to the lack of a 180 degree refocusing pulse.
GRE sequences only ever demonstrate flow related
enhancement and never show wash out signal losses.
EXAM 2026 || MOST RECENT EXAM 2026|2027 ACTUAL
COMPLETE REAL EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) ALREADY GRADED
A+ | GUARANTEED SUCCESS!! NEWEST EXAM | JUST
RELEASED!!
What is cross-talk artefact? - ANSWER-This refers to the
interference which occurs between adjacent slices and is due
to the imperfect nature of RF pulses. Ideally, each RF pulse
would have a rectangular profile supplying maximum amplitude
at the desired frequencies and zero amplitude above or below.
Unfortunately, this is not possible and RF pulse profiles have a
curved component. Whenever a slice is excited there will
always be some excitation of tissue on either side. This can
produce saturation effects with an associated loss of signal
intensity
How can cross-talk artefact be remedied? - ANSWER-Remedies
include: • inter-slice gaps • interleaving within the same TR •
interleaving with separate acquisition for odd and even slices
(which doubles the time)
What is zipper artefact? - ANSWER-The Zipper artefact is
caused by RF breakthrough and is probably the most common
equipment artefact. This appears as a zipper like band of light
and dark pixels passing through the image. It is often two to
three pixels wide and extending across an image in the phase
,encoding direction. It is usually caused by extraneous RF
getting into the examination through some disruption to the RF
shielding - eg. a partially open
door or a conductive cable passed through a wave-guide. This
RF is picked up
by the receive coils and mapped into the image. Another
common cause is RF
emission is from equipment within the examination room
such as a pulse
oximeter.
What are reconstruction artefacts? - ANSWER-The Zipper
artefact is caused by RF breakthrough and is probably the most
common equipment artefact. This appears as a zipper like band
of light and dark pixels passing through the image. It is often
two to three pixels wide and extending across an image in the
phase encoding direction. It is usually caused by extraneous
RF getting into the examination through some disruption to the
RF shielding - eg. a partially open door or a conductive cable
passed through a wave-guide. This RF is picked up by the
receive coils and mapped into the image. Another common
cause is RF emission is from equipment within the examination
room such as a pulse oximeter.
What can certain artefacts indicate in terms of machine
malfunction? -
ANSWER-MRI systems are complex and breakdowns in various
components do happen. The resultant images can be
particularly strange. There appearance however can often help
,in identifying the problem. A skewing of the entire image can be
an indication of a malfunctioning gradient coil or amplifier.
Sometimes although rarely this is also due to the loss of a shim
coil. Reduced intensity or shading through an entire image is
often the result of a failure in the transmit or receive RF chain.
What is MRA? - ANSWER-Magnetic Resonance angiography
(MRA) uses the inherent motion sensitivity of MRI to visualize
blood flow from within vessels. The moving spins in MRI such
as flowing blood have a significant effect on the final signal.
These effects can be image degrading such as artefacts.
However they can also be useful to produce MR angiograms.
The first effect of blood flow is its movement through slices.
The TOF effect arises because some or all of the blood within
an imaged slice is replaced during the repetition time or
between the application of the 90 degree and 180 degree pulses
TE/2.
What are the two main types of MRA? - ANSWER-TOF - Time
of Flight: relies
on flow dependent changes in longitudinal
magnetization.
PC - Phase Contrast: relies on flow dependent changes
in transverse
magnetization.
What signal will blood give if it is "stationary" in a SE MRA? -
ANSWER-If blood is "stationary" the spins will experience both
the 90 degree and 180 degree pulse generating an echo. Now
, whilst blood is never truly stationary unless your patient is
"dead" the signal returned from it is dependent on the blood
velocity and the slice thickness. Thus if we have a thick slice,
slow flowing blood may appear to be "stationary" and thus give
us a signal.
What signal will be returned by blood with a high velocity in a
SE MRA? - ANSWER-When the blood velocity reaches the point
where the blood within a slice has completely left in the time
between the 90 degree and 180 degree pulses then no signal is
returned. This is known as high velocity signal loss or wash
out.
What is occurring in blood that returns an intermediate signal
in a SE MRA? - ANSWER-The third type of signal behavior
occurs at an intermediate stage compared to the above two
examples. This occurs when blood is moving at a speed such
that only some of the blood leaves between the two excitation
pulses. The portion that remains is diluted by fresh blood
flowing into the slice. Only the blood that remains in the slice
receiving both pulses will produce a signal. This results in a
reduction of signal due to the wash out effect.
What are the signal differences of stationary and high velocity
blood in a GE
MRA compared to a SE MRA? - ANSWER-Gradient echo images
are different due to the lack of a 180 degree refocusing pulse.
GRE sequences only ever demonstrate flow related
enhancement and never show wash out signal losses.
