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Animations courtesy of Karla Miller, Oxford
90
o
readout
180
o
position
encoding
Position
decoding
B -ΔB
B +ΔB
B
With diffusion:
spins undergo
continuous motion
1. All spins accrue
phase (with varying
speed) according to
changing position
2. 180
°
pulse flips
magnetization
3. No complete
realignment
Fully refocussed signal
Diffusion-weighted signal
In the presence of
diffusion, the resulting
signal will be lower.
More diffusion
=
Less signal