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ARRT MRI Exam Questions With Correct Answers 100% Verified.

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ARRT MRI Exam Questions With Correct Answers 100% Verified. What is the most abundant element in the human body? - Answerhydrogen nuclei that are available for MRI are those that exhibit a _________ - Answernet spin low energy = spin up = _______ - Answerparallel high energy = spin down = __________ - Answerantiparallel thermal equilibrium - Answerwhen the body is in the magnetic field, spins are aligned, and nothing else has happened B0 - Answerrefers to large magnetic field of the MRI scanner at thermal equilibrium there are a ________ portion of spins with their magnetic moments aligned in the same direction as B0 than against it - Answergreater the reason why SNR increases at higher field strengths is because - Answerthe NMV also increases in size the stronger B0 1 hertz = - Answer1 cycle per second larmour equation - AnswerW0 = y x B0 what do the parts of the larmor equation mean? - AnswerW0 = Larmour frequency (precessional frequency) y = gyromagnetic ratio (42.58 MHz/T for hydrogen) B0 = Field strength what is the precessional frequency for hydrogen at 1.5T? - Answer63.87 MHz (42.58 MHz/T x 1.5T) ©JASONMcCONNELL 2024/2025 ALL RIGHTS RESERVED 1/28/2025. 2 | P a g e out of phase or incoherent - Answermagnetic moments of hydrogen are at different places on the precessional path at a moment in time in phase or coherent - Answermagnetic moments of hydrogen are at the same place on the precessional path at a moment in time what two things do you need to get signal? - Answer1) coherent 2) transverse magnetization phase refers to - Answerthe position of a magnetic moment of a spin on its precessional path at any moment in time B1 field is used to deliver an RF pulse which does what 2 things - Answercauses 1) transverse magnetization and 2) phase precession an RF excitation pulse causes - Answerresonance transverse magnetization occurs at __ degrees to B0 - Answer90 saturation occurs when - Answerspins are unable to absorb more energy or to be stimulated and release more energy what is a saturation pulse - Answer180 degree RF dephasing and relaxation happen at the same time but are - Answerindependent of eachother relaxation - Answerthe process in which hydrogen lose energy (occurs after RF excitation pulse is switched off) dephasing is caused by - Answerfield inhomogeneities in the B0 field and interactions between spins and tissue why is it called FID (free induction decay) - Answerspins FREEly precess influenced only by B0, signal DECAYs with time, and magnetic moments of the spins INDUCE a current in receiver coil when RF excitation pulse is removed, the mag moments of all spins ____ and ______ - Answerdephase and produce a FID TR (repetition time) - Answertime from application of one RF excitation pulse to the application of the next one determines how much longitudinal relaxation occurs (T1 weighting) TE (echo time) - Answertime from application of RF excitation pulse to the peak of the signal induced in the receiver coil ©JASONMcCONNELL 2024/2025 ALL RIGHTS RESERVED 1/28/2025. 3 | P a g e determines how much decay of transverse magnetization occurs (T2 weighting) TR controls - Answerhow much T1 relaxation occurs, recovery of longitudinal magnetization TE controls - Answerhow much T2 decay occurs, decaying signal of transverse magnetization give examples of intrinsic contrast parameters (things that cannot be changed because they are inherent to body's tissues) - Answer- T1 recovery time - T2 decay time - Proton density - Flow - Apparent diffusion coefficient give examples of extrinsic contrast parameters (those that can be changed because they are under our control) - Answer- TR - TE - Flip angle - TI - turbo factor (ETL) - b value describe the process of relaxa

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©JASONMcCONNELL 2024/2025 ALL RIGHTS RESERVED 1/28/2025.




ARRT MRI Exam Questions With Correct
Answers 100% Verified.


What is the most abundant element in the human body? - Answer✔hydrogen

nuclei that are available for MRI are those that exhibit a _________ - Answer✔net spin

low energy = spin up = _______ - Answer✔parallel

high energy = spin down = __________ - Answer✔antiparallel

thermal equilibrium - Answer✔when the body is in the magnetic field, spins are aligned, and
nothing else has happened

B0 - Answer✔refers to large magnetic field of the MRI scanner
at thermal equilibrium there are a ________ portion of spins with their magnetic moments
aligned in the same direction as B0 than against it - Answer✔greater

the reason why SNR increases at higher field strengths is because - Answer✔the NMV also
increases in size the stronger B0

1 hertz = - Answer✔1 cycle per second

larmour equation - Answer✔W0 = y x B0

what do the parts of the larmor equation mean? - Answer✔W0 = Larmour frequency
(precessional frequency)


y = gyromagnetic ratio (42.58 MHz/T for hydrogen)


B0 = Field strength

what is the precessional frequency for hydrogen at 1.5T? - Answer✔63.87 MHz
(42.58 MHz/T x 1.5T)



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, ©JASONMcCONNELL 2024/2025 ALL RIGHTS RESERVED 1/28/2025.


out of phase or incoherent - Answer✔magnetic moments of hydrogen are at different places on
the precessional path at a moment in time

in phase or coherent - Answer✔magnetic moments of hydrogen are at the same place on the
precessional path at a moment in time

what two things do you need to get signal? - Answer✔1) coherent
2) transverse magnetization

phase refers to - Answer✔the position of a magnetic moment of a spin on its precessional path
at any moment in time

B1 field is used to deliver an RF pulse which does what 2 things - Answer✔causes 1) transverse
magnetization
and 2) phase precession

an RF excitation pulse causes - Answer✔resonance

transverse magnetization occurs at __ degrees to B0 - Answer✔90

saturation occurs when - Answer✔spins are unable to absorb more energy or to be stimulated
and release more energy

what is a saturation pulse - Answer✔180 degree RF

dephasing and relaxation happen at the same time but are - Answer✔independent of
eachother

relaxation - Answer✔the process in which hydrogen lose energy (occurs after RF excitation
pulse is switched off)

dephasing is caused by - Answer✔field inhomogeneities in the B0 field and interactions
between spins and tissue

why is it called FID (free induction decay) - Answer✔spins FREEly precess influenced only by B0,
signal DECAYs with time, and magnetic moments of the spins INDUCE a current in receiver coil
when RF excitation pulse is removed, the mag moments of all spins ____ and ______ -
Answer✔dephase and produce a FID

TR (repetition time) - Answer✔time from application of one RF excitation pulse to the
application of the next one


determines how much longitudinal relaxation occurs (T1 weighting)

TE (echo time) - Answer✔time from application of RF excitation pulse to the peak of the signal
induced in the receiver coil

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, ©JASONMcCONNELL 2024/2025 ALL RIGHTS RESERVED 1/28/2025.




determines how much decay of transverse magnetization occurs (T2 weighting)

TR controls - Answer✔how much T1 relaxation occurs, recovery of longitudinal magnetization

TE controls - Answer✔how much T2 decay occurs, decaying signal of transverse magnetization
give examples of intrinsic contrast parameters (things that cannot be changed because they are
inherent to body's tissues) - Answer✔- T1 recovery time
- T2 decay time
- Proton density
- Flow
- Apparent diffusion coefficient
give examples of extrinsic contrast parameters (those that can be changed because they are
under our control) - Answer✔- TR
- TE
- Flip angle
- TI
- turbo factor (ETL)
- b value

describe the process of relaxation - Answer✔- B1 field is turned off
- hydrogen nuclei return to their low-energy state
- magnetic moments dephase
- NMV returns to B0
relaxation therefore results in the _______ longitudinal magnetization and the _____ of
transverse magnetization - Answer✔recovery and decay

which is faster decay or recovery? - Answer✔decay

T1 recovery takes ______ longer than T2 decay - Answer✔5-10 times longer

T1 relaxation is also known as - Answer✔spin lattice energy transfer

T1 recovery - Answer✔is the time it takes for 63% of longitudinal magnetization to recover
(intrinsic)




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