Table 4.

Average brain shift for automatic features and manual landmarks before and after brain shift correction

Registration pairs	Average brain shift: iUS to iUS
	Average distance (SD) between automatic features (mm)		Average distance (SD) between manual landmarks (mm)
	Initial	After FEM	Initial	After thin-plate spline	After FEM
U0–U1	2.11 (0.91)	1.57 (0.52)	2.00 (0.68)	1.52 (0.60)	1.76 (0.47)
U0–U2	3.05 (2.23)	2.19 (1.87)	3.05 (1.68)	3.64 (3.69)	2.35 (1.73)
U0–U1 and U1–U2	2.52 (1.65)	1.84 (1.30)	2.46 (1.30)	2.44 (2.63)	2.02 (1.18)

Brain shift results are reported for all iUS to iUS pairs (U0–U1 and U0–U2) and separately for U0–U1 and U0–U2