2017 Imaging for Physicists Coursebook

Result: geometrical distortion in spin-echo imaging

zyx B ) , ,(

G zyxB ) , ,( 

 

0

x x



x

1

G

G

x

x

frequency-encoding (read-out) direction: • non-linearity of the gradient • static field inhomogeneity (= static difference in resonance frequency)

B  

G

y

y y

1

G

y

phase-encoding direction: • non-linearity of the gradient