Table 1:

Volume (milliliters) of whole brain and brain lobes in 52 control subjects, measured at baseline and again at 12 weeks postbaseline^*

Structure	Baseline		Week 12		Mean Volume Difference		Percent Difference	Pearson Correlation	Concord
	Mean	SD	Mean	SD	Mean	SD	Mean
Whole brain	1190.4	127.0	1192.6	126.9	2.2	25.2	0.22	0.98	0.98
L frontal GM	157.2	16.8	158.6	14.8	1.4	4.7	1.08	0.96	0.95
R frontal GM	160.5	17.7	161.3	16.5	0.8	4.1	0.65	0.97	0.97
L occipital GM	59.3	6.9	59.1	6.4	−0.2	2.1	−0.20	0.95	0.95
R occipital GM	59.4	6.8	59.4	6.3	0.0	2.2	0.11	0.95	0.95
L parietal GM	62.7	7.1	62.4	6.8	−0.3	2.0	−0.34	0.96	0.96
R parietal GM	63.7	7.4	63.6	7.0	−0.1	2.5	−0.01	0.94	0.94
L temporal GM	67.8	8.1	68.0	7.4	0.2	3.0	0.59	0.93	0.92
R temporal GM	68.6	8.7	68.8	7.5	0.2	3.3	0.72	0.93	0.91
L frontal WM	141.9	14.5	142.4	13.4	0.6	5.3	0.58	0.93	0.93
R frontal WM	142.1	16.0	142.3	14.6	0.2	5.3	0.37	0.94	0.94
L occipital WM	17.1	2.9	16.9	2.9	−0.2	1.4	−0.64	0.89	0.88
R occipital WM	17.5	2.6	17.3	2.5	−0.2	1.3	−0.77	0.88	0.88
L parietal WM	46.1	5.7	45.6	5.6	−0.4	1.7	−0.87	0.96	0.95
R parietal WM	46.0	5.0	45.6	4.8	−0.3	1.8	−0.62	0.93	0.93
L temporal WM	36.0	4.9	36.0	4.1	0.0	2.1	0.55	0.90	0.89
R temporal WM	36.1	5.1	36.1	4.3	0.1	2.1	0.71	0.91	0.90
L caudate	4.3	0.6	4.3	0.6	0.0	0.5	1.46	0.58	0.58
R caudate	4.8	0.7	4.7	0.7	0.0	0.6	−0.21	0.57	0.56

Note:—Concord indicates concordance; L, left; R, right; GM, gray matter; WM, white matter.

^*None of the mean volume differences were significant by paired-sample t test, and the Pearson correlation between week 0 and week 12 was generally quite high. Concordance is also a measure of the degree to which values at week 0 and week 12 are correlated, unlike the Pearson, which does not take account of the sample mean, concordance is sensitive to changes in sample mean.