The intensity of the ultrasonic beam will be reduced by which of the following effects?
Absorption
B. Scattering
C. Reflection
D. All of the above
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In a DWI brain image of a stroke patient, ischemic brain tissue will appear to have:
A. ) decreased signal compared to healthy tissue.
B. ) increased signal compared to healthy tissue.
C. ) no difference in signal compared to healthy tissue.
Superconducting wire is used in MRI magnet construction because:
A. ) it is stronger than copper wire.
B. ) its resistance is 0 at 0 degrees C and can carry high current.
C. ) its resistance is 0 at 4K and produces very stable magnetic fields.
In an inversion-recovery experiment, at the null point, t0, for a tissue with a short T1 relaxation time, the tissue will:
A. ) have an observable signal, while long T1 tissue will have no signal.
B. ) have no observable signal, while long T1 tissue will have signal.
C. ) have a similar signal intensity to long T1 tissue.
Fourier Transform of the raw data with respect to the phase direction results in the representation of signal intensity as a function of:
A. ) time.
B. ) frequency.
C. ) position.
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