Table 2:

Intraclass correlation coefficients for 2D-SE and 3D-GE subcortical volume estimates using FreeSurfer and FIRST^a

FreeSurfer Software		FIRST Software
Structure	ICC	Structure	ICC
Estimated TIV	0.942	R caudate	0.914
Subcortical gray volume	0.93	L caudate	0.899
R thalamus	0.903	L hippocampus	0.864
Brain stem	0.865	R thalamus	0.85
L putamen	0.861	L putamen	0.826
L caudate	0.833	R putamen	0.815
R putamen	0.82	R hippocampus	0.814
L ventral diencephalon	0.801	Brain stem	0.784
R ventral diencephalon	0.765	L pallidum	0.781
R pallidum	0.762	L thalamus	0.773
R caudate	0.743	R pallidum	0.605
L thalamus	0.737	R amygdala	0.456
L pallidum	0.71	L amygdala	0.406
R accumbens	0.694	L accumbens	0.25
R hippocampus	0.654	TIVb	0.175
R cerebellum cortex	0.616	R accumbens	0.009
L cerebellum cortex	0.579
L hippocampus	0.568
L accumbens	0.511
R amygdala	0.397
L amygdala	0.321

Note:—L indicates left; R, right.

^aThe ICCs for 2D-SE and 3D-GE subcortical volume estimates using FreeSurfer and FIRST are shown. The ICC values are grouped in 5 categories: 33.3% and 43.8% of the structures with an almost perfect agreement using FreeSurfer and FIRST respectively, 42.9% and 25% of the structures with a substantial agreement using FreeSurfer and FIRST respectively, 14.3% and 12.5% of the structures with a moderate agreement using FreeSurfer and FIRST respectively, 9.5% and 6.25% of the structures with a fair agreement using FreeSurfer and FIRST respectively, and 0% and 12.5% of the structures with a slight agreement using FreeSurfer and FIRST respectively.

^bFIRST total intracranial volume was calculated with the following formula: (FIRST template volume/matrix determinant) × 1000.