Applications Questions & Answers 100%
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For the following spin-echo protocol:
FOV: 320/ TR:500/ TE:25/ SliceThick.:5mm/ Slice Gap:1mm/ Slice.#:9/ NEX:4,
Matrix:192
Decreasing TE will:
a. Decrease the # of allowable slices.
b. Increase the # of allowable slices.
c. Increase scan time.
d. Decrease scan time. - ANSWER-b. Increase the # of allowable slices.
A linear relationship between frequency and position is superimposed on Bo by the Gp.
The H protons' relative precessional frequencies determine:
a. Phase coherence.
b. Phase encoding.
c. Phase shifts.
d. Rephasing - ANSWER-c. Phase shifts.
For the following spin-echo protocol:
FOV: 320/ TR:500/ TE:25/ SliceThick.:5mm/ Slice Gap:1mm/ Slice.#:9/ NEX:4,
Matrix:192
Increasing the FOV will:
a. Increase SNR.
b. Decrease SNR.
c. Decrease Matrix. - ANSWER-a. Increase SNR
A gradient is employed exposing the patient's body to a series of increasing or
decreasing magnetic field strengths for slice selection. In what relation to the slice is this
gradient?
a. Anti-parallel.
b. Perpendicular.
c. Parallel.
d. Oblique. - ANSWER-b. Perpendicular.
In spatial localization, the "logical" Slice Selection Gradient is symbolized:
a. Gz
b. Gy
c. Gx - ANSWER-a. Gz
, The "best" technique for improving image quality is to increase:
a. TR
b. NEX
c. Matrix
d. FOV - ANSWER-b. NEX
The two types of enhancement media, described by Lauffer, the mechanism of T2
agents is:
a. To increase T2 relaxation time, thus emitting low signal.
b. To decrease T2 relaxation time, thus emitting low signal.
c. To increase T2 relaxation time, thus emitting high signal.
d. To decrease T2 relaxation time, thus emitting high signal - ANSWER-b. To decrease
T2 relaxation time, thus emitting low signal.
The number (#) of slices formula is:
a. TR x TE x delta.
b. TR + TE + delta.
c. TR / (TE+delta). - ANSWER-c. TR / (TE+delta).
A generation of frequency differences along a particular direction of a slice is called:
a. Frequency encoding.
b. Fourier transform.
c. Phase encoding.
d. Slice selection. - ANSWER-a. Frequency encoding.
Using the following protocol, determine the scan time for this pulse sequence: (round off
your answer to the nearest minute.)
FOV: 320mm, TR: 2000ms, TE 20/80ms, NEX: 1, Matrix: 256x128
a. 3 mins.
b. 4 mins.
c. 6 mins.
d. 12 mins. - ANSWER-b. 4 mins.
What pulse imaging technique is employed in all implementations of MRA?
a. Spin-echo.
b. STIR.
c. Gradient-echo.
d. FLAIR. - ANSWER-c. Gradient-echo.
In a horizontal field magnet, what is the primary Gs for a Sagittal Slice?
a. Gx
b. Gy
c. Gz - ANSWER-a. Gx