Table 2.

Voxel tissue fractions^a

Variable	Younger	Middle	Older
ACC CSF %	11.9 ± 2.90*	14.6 ± 6.13*	25.4 ± 7.45**
ACC GM/WM	2.76 ± 0.55*	2.29 ± 0.47*	2.51 ± 0.49
DLPFC CSF %	4.26 ± 1.73*	4.18 ± 2.86*	7.78 ± 3.73**
DLPFC GM/WM	0.44 ± 0.13	0.41 ± 0.13	0.50 ± 0.14
Hippocampus CSF %	4.23 ± 1.60*	6.61 ± 5.76*	12.5 ± 4.35**
Hippocampus GM/WM	1.11 ± 0.17	1.02 ± 0.23	1.11 ± 0.11
Thalamus CSF %	<0.00 ± <0.00	<0.00 ± <0.00	<0.00 ± <0.00
Thalamus GM/WM	2.06 ± 0.86*	1.74 ± 0.79*	1.13 ± 0.45**

^aData are mean ± SD.

Age groups that are pairwise significantly different (p < 0.05):

*different from one other group;

**different from both other groups. For CSF fraction in thalamus, the concentrations were too low to perform statistical tests.