| PHYS/BIOL 464 Medical ImagingInstrumentation MRI HW 7A |
1.During the magnetic resonance relaxation process after a 90°pulse:
A, Longitudinal magnetization increases
B. Transverse magnetization increases
C. Proton density increases
2. T1 and T2 values depend on:
A. Voxel size.
B. Direction of magnetic field.
C. Type of tissue.
3.Tissue characteristics which can produce a relative andincreased intensity (brightness) contrast in a magnetic resonanceimage include which of the two following factors (choose two):
A. Short T1 values.
B. Long T1 values.
C. Short T2 values.
D. Long T2 values.
4. The process of averaging is used in MRI for the purposeof:
A. Reducing acquisition time.
B. Reducing image noise.
C. Improving detail.
D. Combining T1 and T2 contrast.
5. The amount of time necessary to acquire an MR image dependson which two factors (choose two):
A. TR
B. TE
C. Field of view
D. Matrix size
6. T1 increases with magnetic field.
A. True
B. False
