Table 4.

T2 values of the NP and the AF by donor age group and disc level. The mean and standard error of the mean at the (A) NP and (B) AF, and (C) counts. Results of random effects linear regression models for (D) NP and (E) AF.

A. Mean ± Standard Error of T2 value of the NP
Age	L1–2	L2–3	L3–4	L4–5	Total
<40	124.1 ± 7.3	110.7 ± 7.6	93.8 ± 19.2	97.5 ± 21.5	106.6 ± 7.5
40–49	91.1 ± 13.8	89.9 ± 6.5	80.3 ± 13.4	91.7 ± 13.1	88.2 ± 5.5
50–59	80.0 ± 4.1	70.1 ± 2.8	67.1 ± 2.9	71.8 ± 3.1	72.3 ± 1.7
60–69	73.5 ± 4.5	67.7 ± 4.4	62.8 ± 2.8	62.6 ± 2.4	66.7 ± 1.9
70+	69.2 ± 7.4	56.6 ± 3.3	59.7 ± 4.7	59.0 ± 4.1	61.1 ± 2.6
all ages	79.6 ± 2.9	71.0 ± 2.4	67.0 ± 2.2	69.7 ± 2.4	71.8 ± 1.3

B. Mean ± Standard Error of T2 value of the AF
Age	L1–2	L2–3	L3–4	L4–5	Total
<40	42.0 ± 3.4	34.9 ± 1.3	32.0 ± 0.9	33.3 ± 1.3	35.6 ± 1.3
40–49	38.3 ± 4.4	37.8 ± 2.8	35.3 ± 1.3	36.9 ± 1.4	37.1 ± 1.3
50–59	39.7 ± 1.2	37.3 ± 0.9	36.2 ± 0.7	40.3 ± 1.3	38.4 ± 0.5
60–69	38.4 ± 1.4	34.8 ± 1.0	35.5 ± 1.0	36.7 ± 1.0	36.3 ± 0.6
70+	43.3 ± 5.8	36.2 ± 3.0	40.6 ± 4.4	44.4 ± 3.7	41.1 ± 2.2
all ages	39.8 ± 1.0	36.2 ± 0.6	36.2 ± 0.7	39.0 ± 0.9	37.8 ± 0.4

C. Counts
Age	L1–2	L2–3	L3–4	L4–5	Total
<40	4	4	4	4	16
40–49	4	4	4	4	16
50–59	29	30	30	30	119
60–69	24	24	23	24	95
70+	9	9	9	9	36
all ages	70	71	70	71	282

D. Linear regression: T2 of NP as a function of disc level, age, and sex
Factors	Value	Std. Error	DF	t-value	p-value
Intercept	126.5	9.6	209	13.2	<0.001
L1–2	9.9	2.6	209	3.8	<0.001
L2–3	1.3	2.6	209	0.5	0.609
L3–4	−2.7	2.6	209	−1.1	0.292
(Ref. L4–5)
Age	−1.0	0.2	68	−6.5	<0.001
Sex (M)	4.9	3.8	68	1.3	0.205

E. Linear regression: T2 of AF as a function of disc level, age, and sex
Factors	Value	Std. Error	DF	t-value	p-value
Intercept	34.9	3.8	208	9.1	<0.001
L1–2	0.8	0.9	208	0.8	0.403
L2–3	−2.8	0.9	208	−3.1	0.002
L3–4	−2.8	0.9	208	−3.1	0.002
(Ref. L4–5)
Age	0.1	0.1	68	1.4	0.171
Sex (M)	−1.4	1.5	68	−0.9	0.373