Table 2.

Distortion magnitudes when applying distortion correction using the grid sheet phantom method

Distance from isocenter (mm)	2D T2-weighted FSE		3D T2-weighted FSE		3D T1-weighted GRE
	Mean ± SD (mm)	Maximum (mm)	Mean ± SD (mm)	Maximum (mm)	Mean ± SD (mm)	Maximum (mm)
0–20	0.55 ± 0.26	0.98	0.33 ± 0.18	0.72	0.52 ± 0.24	0.97
20–40	0.47 ± 0.23	0.90	0.43 ± 0.20	0.88	0.49 ± 0.21	1.11
40–60	0.55 ± 0.27	1.47	0.50 ± 0.24	1.05	0.49 ± 0.26	1.18
60–80	0.62 ± 0.32	1.39	0.52 ± 0.27	1.24	0.55 ± 0.31	1.35
80–100	0.66 ± 0.34	1.82	0.56 ± 0.27	1.21	0.57 ± 0.31	1.39
100–120	0.74 ± 0.34	1.65	0.60 ± 0.31	1.64	0.68 ± 0.33	1.66
120–140	0.88 ± 0.39	2.09	0.77 ± 0.34	1.87	0.81 ± 0.40	1.93
140–160	0.99 ± 0.45	2.08	0.81 ± 0.39	2.24	0.99 ± 0.48	2.65
160–180	1.23 ± 0.66	3.75	0.97 ± 0.54	2.75	1.21 ± 0.74	4.24
180–200	1.53 ± 1.05	5.89	1.19 ± 0.75	3.77	1.48 ± 1.14	6.23
200–220	1.73 ± 1.19	5.93	1.34 ± 0.86	4.34	1.80 ± 1.28	6.71
220–240	2.24 ± 1.17	5.45	1.51 ± 0.78	3.55	2.67 ± 1.81	7.15

2D: two-dimensional

3D: three-dimensional

FSE: fast spin-echo

GRE: gradient-echo

SD: standard deviation