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ASMIRT MRI Accreditation Exam Questions Version
1/ASMIRT MRI Accreditation prep Exam Questions
and Answers Practice Questions with Solutions Newest
2026-2027 Complete Questions And Correct Detailed
Answers| Already Graded A+
What physical law, forms the basis on MRI signal generation? -
ANSWER-According to Faraday's law of induction, a changing
magnetic field will generate a voltage in a suitably located
receiver coil. This is the basis of signal detection in MRI
How is signal detected in MRI? - ANSWER-For a signal to be
detected, the magnetisation induced by Bo in the direction of Bo
needs to be converted into a magnetisation which precesses in
the X-Y plane. This is done by applying a RF pulse (B1) that
causes the NMV to flip and precess in the transverse plane.
NMV will precess about B1 which can be pulsed for as long as
it takes to rotate the magnetisation through 90 degrees into the
transverse plane. Individual protons will now be precessing in
phase to produce a rotating magnetisation which can be detected
with a receiver coil.
What happens to MRI signal over time and what is this called? -
ANSWER-When a scanning sequence starts, the magnetisation
,2|Page
in the longitudinal plane is flipped into the transverse plane
using an RF pulse. This creates a measurable signal in the
receiver coil. Over time this signal fades away or decays. This is
known as relaxation of the signal. After the RF pulse, the NMV
moves back towards the longitudinal plane via two relaxation
processes.
What are the two types of relaxation in MRI? - ANSWER-•
Spin-Lattice Relaxation, T1 Relaxation
• Spin-Spin Relaxation, T2 Relaxation or T2 decay
What is T1 relaxation? - ANSWER-T1 relaxation is commonly
referred to as spin-lattice relaxation as the interactions that are
involved in this relaxation mechanism are between the protons
(or spins) and their environment. This type of relaxation deals
with the longitudinal component of the magnetisation and T1 is
a measure of the time in which it takes the longitudinal
component of magnetisation to reach 63% of its initial value.
Why is it called spin-lattice relaxation? - ANSWER-T1
relaxation therefore is the regrowth of the magnetisation along
the longitudinal axis. As spins realign themselves with the
longitudinal axis, they must give up some energy. This energy is
given up to the environment in which the spins reside to other
,3|Page
nearby electrons or nuclei. Thus, the energy from spins is given
to the lattice of surrounding structures
What equation governs T1 relaxation? - ANSWER-An
important equation governs T1 relaxation and Net
Magnetisation. It is often the subject of examinations. Basically
it states the following. Net magnetisation is not achieved
instantaneously. From the time the field is applied, M grows
from zero towards its equilibrium value (Mo) along the Z axis in
an exponential fashion such that Mz = Mo(1-exp(-t/T1))
What is T2 relaxation? - ANSWER-T2 decay is caused by
protons exchanging energy with neighbouring protons. The
energy exchange is caused by the interaction between the
magnetic fields of adjacent protons. This rate of decay is an
exponential process and the T2 time of a tissue is the time it
takes for 63% of the transverse magnetisation to be lost. Often
the T2 time is also described as the time it takes for 37% of
transverse magnetisation to remain.
Why is it known as spin-spin relaxation? - ANSWER-It is
known as spin spin relaxation due to the interaction between the
spins or protons and results in the decay or loss of transverse
magnetisation.
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What is TR? - ANSWER-The repetition time: Is the time from
the application of one RF pulse to the application of the next RF
pulse and is measured in milliseconds (ms). The TR determines
the amount of relaxation that is allowed to occur between the
end of one RF pulse and the application of the next. Thus TR
determines the amount of T1 relaxation that has occurred.
What is TE? - ANSWER-The echo time: Is the time from the
application of the RF pulse to when the signal is read in the
receiver coil and is also measured in ms. The TE determines
how much T2 decay of transverse magnetisation is allowed to
occur before the signal is read. Thus TE controls the amount of
T2 relaxation or decay that has occurred.
What does PD weighting measure? - ANSWER-Proton density
contrast is a consequence of the relative number of protons per
unit volume a tissue contains. To produce contrast differences as
a result of PD the transverse component of magnetisation must
reflect these differences. Tissues with a high PD will return a
high signal, whereas tissues with a low PD will return a low
signal.
ASMIRT MRI Accreditation Exam Questions Version
1/ASMIRT MRI Accreditation prep Exam Questions
and Answers Practice Questions with Solutions Newest
2026-2027 Complete Questions And Correct Detailed
Answers| Already Graded A+
What physical law, forms the basis on MRI signal generation? -
ANSWER-According to Faraday's law of induction, a changing
magnetic field will generate a voltage in a suitably located
receiver coil. This is the basis of signal detection in MRI
How is signal detected in MRI? - ANSWER-For a signal to be
detected, the magnetisation induced by Bo in the direction of Bo
needs to be converted into a magnetisation which precesses in
the X-Y plane. This is done by applying a RF pulse (B1) that
causes the NMV to flip and precess in the transverse plane.
NMV will precess about B1 which can be pulsed for as long as
it takes to rotate the magnetisation through 90 degrees into the
transverse plane. Individual protons will now be precessing in
phase to produce a rotating magnetisation which can be detected
with a receiver coil.
What happens to MRI signal over time and what is this called? -
ANSWER-When a scanning sequence starts, the magnetisation
,2|Page
in the longitudinal plane is flipped into the transverse plane
using an RF pulse. This creates a measurable signal in the
receiver coil. Over time this signal fades away or decays. This is
known as relaxation of the signal. After the RF pulse, the NMV
moves back towards the longitudinal plane via two relaxation
processes.
What are the two types of relaxation in MRI? - ANSWER-•
Spin-Lattice Relaxation, T1 Relaxation
• Spin-Spin Relaxation, T2 Relaxation or T2 decay
What is T1 relaxation? - ANSWER-T1 relaxation is commonly
referred to as spin-lattice relaxation as the interactions that are
involved in this relaxation mechanism are between the protons
(or spins) and their environment. This type of relaxation deals
with the longitudinal component of the magnetisation and T1 is
a measure of the time in which it takes the longitudinal
component of magnetisation to reach 63% of its initial value.
Why is it called spin-lattice relaxation? - ANSWER-T1
relaxation therefore is the regrowth of the magnetisation along
the longitudinal axis. As spins realign themselves with the
longitudinal axis, they must give up some energy. This energy is
given up to the environment in which the spins reside to other
,3|Page
nearby electrons or nuclei. Thus, the energy from spins is given
to the lattice of surrounding structures
What equation governs T1 relaxation? - ANSWER-An
important equation governs T1 relaxation and Net
Magnetisation. It is often the subject of examinations. Basically
it states the following. Net magnetisation is not achieved
instantaneously. From the time the field is applied, M grows
from zero towards its equilibrium value (Mo) along the Z axis in
an exponential fashion such that Mz = Mo(1-exp(-t/T1))
What is T2 relaxation? - ANSWER-T2 decay is caused by
protons exchanging energy with neighbouring protons. The
energy exchange is caused by the interaction between the
magnetic fields of adjacent protons. This rate of decay is an
exponential process and the T2 time of a tissue is the time it
takes for 63% of the transverse magnetisation to be lost. Often
the T2 time is also described as the time it takes for 37% of
transverse magnetisation to remain.
Why is it known as spin-spin relaxation? - ANSWER-It is
known as spin spin relaxation due to the interaction between the
spins or protons and results in the decay or loss of transverse
magnetisation.
, 4|Page
What is TR? - ANSWER-The repetition time: Is the time from
the application of one RF pulse to the application of the next RF
pulse and is measured in milliseconds (ms). The TR determines
the amount of relaxation that is allowed to occur between the
end of one RF pulse and the application of the next. Thus TR
determines the amount of T1 relaxation that has occurred.
What is TE? - ANSWER-The echo time: Is the time from the
application of the RF pulse to when the signal is read in the
receiver coil and is also measured in ms. The TE determines
how much T2 decay of transverse magnetisation is allowed to
occur before the signal is read. Thus TE controls the amount of
T2 relaxation or decay that has occurred.
What does PD weighting measure? - ANSWER-Proton density
contrast is a consequence of the relative number of protons per
unit volume a tissue contains. To produce contrast differences as
a result of PD the transverse component of magnetisation must
reflect these differences. Tissues with a high PD will return a
high signal, whereas tissues with a low PD will return a low
signal.
