ASMIRT – MRI Accreditation Exam
With Questions And Answers Updated
2026/2027|Graded A+
To achieve T1 weighting in a GRE sequence, what parameters should be set? - ANSWER>• T1 Weighting
in GRE
Large Flip angle 70-110 degrees
Short TE 5-10ms
Short TR < 50ms
To achieve T2 weighting in a GRE sequence, what parameters should be set? - ANSWER>T2* Weighting in
GRE
Small flip angle 5-20 degrees
Long TE 15-25ms
Short TR minimum possible depending on number of slices as the small flip angle ensures rapid T1
recovery
,To achieve PD weighting in a GRE sequence, what parameters should be set? - ANSWER>PD Weighting in
GRE Small flip angle 5-20 degrees Short TE 5-10ms Short TR minimum possible depending on number of
slices as the small flip angle ensures rapid T1 recovery
What is steady state? - ANSWER>This is the condition that applies when the TR used is shorter than the
T1 and the T2 of the tissue. There will not be enough time for the transverse magnetization to have
decayed away before the next RF pulse is applied. Each RF pulse produces an FID, each pair of pulses
produces a Hahn echo, and stimulated echoes arise from each set of three or more pulses. If the TR is
short enough, the tails of the FID's and the spin echoes merge to produce a continuous signal of varying
amplitude. The signal contains both FID and spin-echo components, with the TR being equal to the TAU
of the spin-echo
Explain how the residual transverse magnetization is can be removed in a steady state sequence? -
ANSWER>The use of short TR intervals creates the steady state condition, but with these sequences the
residual transverse magnetization is deliberately removed or 'spoiled' before the next excitation pulse.
Spoiling is done by;
• Gradient spoiling, where a gradient of varying amplitude is turned on just before the next RF pulse.
(Siemens' Flash)
, • RF spoiling, where the phase of the RF is changed with each excitation and the receiver locks on only to
the phase of the preceding pulse. (GE's SPGR
What are gradient echo incoherent/spoiled gradient echo sequences usually used to for in terms of
weighting - ANSWER>These sequences are used to produce rapid T1 weighted images. e.g. breath-hold
liver studies. Only the FID is re-phased - the spin-echo is spoiled and not sampled.
For GRE incoherent T1 weighted scans the following parameters are suggested - ANSWER>•Flip angle 30-
45 degree
•Short TE : minimum possible: often two are used for in and out of phase (minimum TE ensures minimal
T2*) •Short TR : 20-50ms
How is a coherent gradient echo sequence achieved? - ANSWER>Short TR values ensure that the steady
state is achieved with these sequences. The transverse magnetization left over at the time of the next
excitation pulse is kept coherent using a re-winder gradient after readout. This compensates for the
dephasing which occurs due to the phase encoding process.
With Questions And Answers Updated
2026/2027|Graded A+
To achieve T1 weighting in a GRE sequence, what parameters should be set? - ANSWER>• T1 Weighting
in GRE
Large Flip angle 70-110 degrees
Short TE 5-10ms
Short TR < 50ms
To achieve T2 weighting in a GRE sequence, what parameters should be set? - ANSWER>T2* Weighting in
GRE
Small flip angle 5-20 degrees
Long TE 15-25ms
Short TR minimum possible depending on number of slices as the small flip angle ensures rapid T1
recovery
,To achieve PD weighting in a GRE sequence, what parameters should be set? - ANSWER>PD Weighting in
GRE Small flip angle 5-20 degrees Short TE 5-10ms Short TR minimum possible depending on number of
slices as the small flip angle ensures rapid T1 recovery
What is steady state? - ANSWER>This is the condition that applies when the TR used is shorter than the
T1 and the T2 of the tissue. There will not be enough time for the transverse magnetization to have
decayed away before the next RF pulse is applied. Each RF pulse produces an FID, each pair of pulses
produces a Hahn echo, and stimulated echoes arise from each set of three or more pulses. If the TR is
short enough, the tails of the FID's and the spin echoes merge to produce a continuous signal of varying
amplitude. The signal contains both FID and spin-echo components, with the TR being equal to the TAU
of the spin-echo
Explain how the residual transverse magnetization is can be removed in a steady state sequence? -
ANSWER>The use of short TR intervals creates the steady state condition, but with these sequences the
residual transverse magnetization is deliberately removed or 'spoiled' before the next excitation pulse.
Spoiling is done by;
• Gradient spoiling, where a gradient of varying amplitude is turned on just before the next RF pulse.
(Siemens' Flash)
, • RF spoiling, where the phase of the RF is changed with each excitation and the receiver locks on only to
the phase of the preceding pulse. (GE's SPGR
What are gradient echo incoherent/spoiled gradient echo sequences usually used to for in terms of
weighting - ANSWER>These sequences are used to produce rapid T1 weighted images. e.g. breath-hold
liver studies. Only the FID is re-phased - the spin-echo is spoiled and not sampled.
For GRE incoherent T1 weighted scans the following parameters are suggested - ANSWER>•Flip angle 30-
45 degree
•Short TE : minimum possible: often two are used for in and out of phase (minimum TE ensures minimal
T2*) •Short TR : 20-50ms
How is a coherent gradient echo sequence achieved? - ANSWER>Short TR values ensure that the steady
state is achieved with these sequences. The transverse magnetization left over at the time of the next
excitation pulse is kept coherent using a re-winder gradient after readout. This compensates for the
dephasing which occurs due to the phase encoding process.
