Table 1:

Accuracy of the automatic methods for estimating ICV compared with manual delineation^{^a}

	FreeSurfer	Opt FreeSurfer	RBM	RBM Multi	ARBM	ARBM Multi
Volume difference (mL)
Mean (SD)	111.25 (53.62)	0.21 (53.02)	−9.17 (42.34)	2.49 (26.72)	−0.07 (41.64)	30.29 (26.75)
Absolute mean (SD)	111.25 (53.62)	40.11 (33.86)	34.38 (25.63)	20.66 (16.69)	34.57 (22.31)	33.71 (22.12)
Volume difference (%)
DIFF (SD)	7.3 (3.7)	−0.1 (3.5)	−0.6 (2.7)	0.1 (1.7)	−0.1 (2.6)	1.9 (1.7)
ADIFF (SD)	7.3 (3.7)	2.6 (2.3)	2.2 (1.6)	1.3 (1.1)	2.2 (1.4)	2.1 (1.3)
ICC	0.96	0.96	0.97	0.99	0.97	0.99
Dice overlap (mean) (SD)	NA^{^b}	NA^{^b}	0.96 (0.01)	0.97 (0.01)	0.96 (0.01)	0.97 (0.00)

Note:—DIFF indicates volume difference; ADIFF, absolute volume difference; NA, not applicable.
↵a Positive differences indicate that the manual measurements were larger.
↵b Calculation not possible because FreeSurfer does not produce an ICV mask.