Table 4.

Image distortions.

	Nonlinear Image Distortion in EPI Along Phase Encoding Direction (standard error in mm)	Distortion by Diffusion Encoding Gradient
Site ID		Mean of Grid Line Shift (median and range in mm)	SD of Grid Line Shift (median and range in mm)
1 a	0.7	$-0.04(-0.07,0.09)$	0.16 (0.01, 0.34)
2 a	0.8	$-0.04(-0.21,0.88)$	0.53 (0.28, 0.93)
3	6.4	$0.01(-0.13,0.25)$	0.11 (0.01, 0.60)
4 b	3.8	$-0.07(-0.14,0.06)$	0.24 (0.18, 0.57)
	0.6	$0.01(-0.07,0.13)$	0.30 (0.05, 0.57)
5 c	3.2	$0.03(-0.12,0.60)$	0.17 (0.02, 0.58)
	0.6	$0.00(-0.10,0.10)$	0.14 (0.02, 0.34)
6 a	0.6	$-0.01(-0.16,0.10)$	0.28 (0.07, 0.50)
7 c	2.9	$0.03(-0.10,0.19)$	0.20 (0.03, 0.62)
	0.4	$0.00(-0.12,0.07)$	0.18 (0.04, 0.45)
8 a	0.7	$0.01(-0.05,0.04)$	0.17 (0.09, 0.27)

^aHigher order shim was used.

^bTwo measurements were done in the same session; the first one used the first order shim and the second one used higher order shim.

^cTwo measurements were done in different days; the first one used the first order shim and the second one used higher order shim.