2016_Imaging for Physicists

Impact on geometrical accuracy

Group y-terms for distortions in fase-encoding direction:

y y ∆ −= TGmy Tzyx Bm TG ym y 1 ) , ,( γ

G ∆ − ∆ − ∆

γ

γ

y y

y

and solve for y 1

B ∆ += ∆

G

y y

y

1

G

∆

y

Assuming that the errors in the gradient are independent of the gradient step, this is equal to

G B y y y ∆ +=

1

G

y