2017 Imaging for Physicists Coursebook

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Gradients
• Recall that the resonant frequency
is proportional to field strength
• Magnetic gradient changes B 0 field
strength over distance
• In MRI a linear gradient changes the
resonant frequency in a given
direction
dy
dB
G y
0 
0 0 B   
dz
dB
G z
0 
dx
dB
Gx
0 
) ( 0 x xG B    