Significant associations (P < .01) of the regional metabolite concentrations and transverse relaxation times with age, derived with linear regressions

ROI	Parameter	Mean^{^a}	SD	R	P	No.^{^b}	Intercept	Slope	Variation in 50 Yr (%)^{^c}
Occipital GM	NAA	13.2	1.6	−0.40	.002	59	15.16	−0.04	−16
Occipital GM	T2′	56.7	9.4	−0.45	.000	60	69.67	−0.30	−23
Putamen	NAA	13.2	1.5	−0.51	.000	60	15.54	−0.05	−19
	tCr	10.2	1.4	−0.39	.002	60	11.89	−0.04	−17
	T2′	55.1	13.1	−0.68	.000	60	83.44	−0.66	−47
Pallidum^{^d}	T2′	32.3	6.4	−0.34	.005	40	41.53	−0.24	−26^{^e}
HK	T2′	63.6	10.5	−0.35	.007	60	76.72	−0.28	−20
SCC	NAA	10.9	1.9	−0.36	.005	60	13.01	−0.05	−19
	T2	105.1	9.3	−0.47	.000	60	118.50	−0.31	−14
	T2′	57.5	7.4	0.40	.002	60	45.14	0.36	35
CbWM	T2	120.5	8.3	0.45	.000	60	108.93	0.26	12
BSv	NAA	13.4	2.4	−0.42	.003	50	16.73	−0.08	−26
BSd	tCr	9.2	1.3	−0.35	.010	53	10.64	−0.03	−16

Note:—R indicates the Pearson correlation coefficient.
↵a In ratio to internal water for metabolites and in milliseconds for relaxation times.
↵b Values of several ROIs were not sampled for all subjects (n < 60) due to artifacts.
↵c In ratio to the values at 20 years of age.
↵d The values for subjects older than 60 years were not sampled for linear regression.
↵e Variation in 40 years. Significant linear relation of T2′ to age in the pallidum was found for the ages between 20 and 60 years (P < .01), but not for the whole age range (21–70 years, P > .01).