MRI Imaging Protocols Exam Questions
with Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
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Question 1
Which parameter primarily controls longitudinal magnetization recovery and
therefore strongly influences T1 weighting?
A. TE
B. TR
C. Bandwidth
D. Echo-train length
Answer: B
Rationale: TR, or repetition time, determines how much longitudinal
magnetization can recover between successive RF excitations. A shorter TR
generally increases T1 weighting, while a longer TR allows greater longitudinal
recovery and reduces T1 weighting.
Question 2
Which parameter has the greatest direct influence on T2 weighting in a
conventional spin-echo sequence?
A. FOV
B. Matrix
C. TE
D. Number of excitations
Answer: C
,Rationale: TE determines how long transverse magnetization is allowed to decay
before the signal is measured. A longer TE increases T2 weighting because tissues
with different T2 relaxation times lose transverse magnetization at different rates.
Question 3
A technologist wants to increase in-plane spatial resolution while maintaining the
same field of view. Which change is most appropriate?
A. Decrease the acquisition matrix
B. Increase the slice gap
C. Increase the acquisition matrix
D. Increase the TR
Answer: C
Rationale: Increasing the matrix while maintaining the same FOV decreases pixel
dimensions. Smaller pixels provide higher in-plane spatial resolution, although the
change can reduce SNR and potentially increase acquisition time.
Question 4
How is in-plane pixel size in the frequency direction calculated?
A. Matrix ÷ FOV
B. Slice thickness ÷ matrix
C. Frequency-direction FOV ÷ frequency matrix
D. TR ÷ TE
Answer: C
Rationale: Pixel size is determined by dividing the field of view in a particular
direction by the number of acquired encoding steps in that direction. ACR uses this
relationship when evaluating MRI spatial resolution.
Question 5
,Which change generally increases signal-to-noise ratio when other parameters
remain constant?
A. Decreasing NEX
B. Decreasing voxel volume
C. Increasing NEX
D. Increasing receiver bandwidth
Answer: C
Rationale: Increasing the number of excitations, or NEX/NSA, provides additional
signal measurements that are averaged together. This improves SNR, although
acquisition time also increases.
Question 6
What is the primary effect of increasing voxel size?
A. Lower SNR and higher spatial resolution
B. Higher SNR and lower spatial resolution
C. Higher spatial resolution with no SNR change
D. Elimination of partial-volume effects
Answer: B
Rationale: Larger voxels contain more spins and therefore generally produce
higher SNR. However, larger voxels reduce the ability to distinguish small adjacent
structures and increase partial-volume averaging.
Question 7
Which change generally produces thinner slices?
A. Increasing slice thickness
B. Decreasing the matrix
C. Reducing the prescribed slice thickness
D. Increasing NEX
Answer: C
, Rationale: Slice thickness is directly specified during protocol planning. Reducing it
improves through-plane spatial resolution but generally decreases SNR because
each voxel contains fewer spins.
Question 8
What is the main purpose of a localizer or scout sequence?
A. Provide the final diagnostic images
B. Measure the patient's blood pressure
C. Establish anatomy and assist with planning subsequent imaging planes
D. Suppress all fat signal
Answer: C
Rationale: Localizers provide rapid low-resolution images that allow the
technologist to identify anatomy and accurately prescribe the diagnostic
sequences and imaging planes.
Question 9
Which sequence is most commonly associated with strong fluid signal?
A. T1-weighted spin echo
B. T2-weighted imaging
C. T1-weighted inversion recovery
D. In-phase gradient echo
Answer: B
Rationale: Fluid has a relatively long T2 relaxation time and therefore remains
relatively bright on appropriately T2-weighted sequences. T2-weighted imaging is
particularly useful for detecting many fluid-containing or edematous
abnormalities.
Question 10
with Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
Question 1
Which parameter primarily controls longitudinal magnetization recovery and
therefore strongly influences T1 weighting?
A. TE
B. TR
C. Bandwidth
D. Echo-train length
Answer: B
Rationale: TR, or repetition time, determines how much longitudinal
magnetization can recover between successive RF excitations. A shorter TR
generally increases T1 weighting, while a longer TR allows greater longitudinal
recovery and reduces T1 weighting.
Question 2
Which parameter has the greatest direct influence on T2 weighting in a
conventional spin-echo sequence?
A. FOV
B. Matrix
C. TE
D. Number of excitations
Answer: C
,Rationale: TE determines how long transverse magnetization is allowed to decay
before the signal is measured. A longer TE increases T2 weighting because tissues
with different T2 relaxation times lose transverse magnetization at different rates.
Question 3
A technologist wants to increase in-plane spatial resolution while maintaining the
same field of view. Which change is most appropriate?
A. Decrease the acquisition matrix
B. Increase the slice gap
C. Increase the acquisition matrix
D. Increase the TR
Answer: C
Rationale: Increasing the matrix while maintaining the same FOV decreases pixel
dimensions. Smaller pixels provide higher in-plane spatial resolution, although the
change can reduce SNR and potentially increase acquisition time.
Question 4
How is in-plane pixel size in the frequency direction calculated?
A. Matrix ÷ FOV
B. Slice thickness ÷ matrix
C. Frequency-direction FOV ÷ frequency matrix
D. TR ÷ TE
Answer: C
Rationale: Pixel size is determined by dividing the field of view in a particular
direction by the number of acquired encoding steps in that direction. ACR uses this
relationship when evaluating MRI spatial resolution.
Question 5
,Which change generally increases signal-to-noise ratio when other parameters
remain constant?
A. Decreasing NEX
B. Decreasing voxel volume
C. Increasing NEX
D. Increasing receiver bandwidth
Answer: C
Rationale: Increasing the number of excitations, or NEX/NSA, provides additional
signal measurements that are averaged together. This improves SNR, although
acquisition time also increases.
Question 6
What is the primary effect of increasing voxel size?
A. Lower SNR and higher spatial resolution
B. Higher SNR and lower spatial resolution
C. Higher spatial resolution with no SNR change
D. Elimination of partial-volume effects
Answer: B
Rationale: Larger voxels contain more spins and therefore generally produce
higher SNR. However, larger voxels reduce the ability to distinguish small adjacent
structures and increase partial-volume averaging.
Question 7
Which change generally produces thinner slices?
A. Increasing slice thickness
B. Decreasing the matrix
C. Reducing the prescribed slice thickness
D. Increasing NEX
Answer: C
, Rationale: Slice thickness is directly specified during protocol planning. Reducing it
improves through-plane spatial resolution but generally decreases SNR because
each voxel contains fewer spins.
Question 8
What is the main purpose of a localizer or scout sequence?
A. Provide the final diagnostic images
B. Measure the patient's blood pressure
C. Establish anatomy and assist with planning subsequent imaging planes
D. Suppress all fat signal
Answer: C
Rationale: Localizers provide rapid low-resolution images that allow the
technologist to identify anatomy and accurately prescribe the diagnostic
sequences and imaging planes.
Question 9
Which sequence is most commonly associated with strong fluid signal?
A. T1-weighted spin echo
B. T2-weighted imaging
C. T1-weighted inversion recovery
D. In-phase gradient echo
Answer: B
Rationale: Fluid has a relatively long T2 relaxation time and therefore remains
relatively bright on appropriately T2-weighted sequences. T2-weighted imaging is
particularly useful for detecting many fluid-containing or edematous
abnormalities.
Question 10
