Table 1.

Test-retest reliability statistics for microstructure measures. Units (mean and SD) for MD and RD = 10⁻³ mm²/s; units for R₁ = s⁻¹, CV = averaged within subject, ICC = averaged across 5 repeated measures.

Metric	Tract	Mean	SD	CV (%)	ICC	ICC pval	r
FA		0.47	0.005	1.0	0.93	<0.0001	0.82
MD		1.00	0.010	0.9	0.94	<0.0001	0.87
RD		1.00	0.004	0.6	0.96	<0.0001	0.88
RSF		0.13	0.003	2.1	0.88	<0.0001	0.65
MMPF	Fornix	0.05	0.001	2.6	0.95	<0.0001	0.85
MWF		0.07	0.003	4.2	0.95	<0.0001	0.87
R1		0.77	0.005	0.7	0.97	<0.0001	0.90
MTR		0.35	0.0004	0.1	0.94	<0.0001	0.77
FA		0.55	0.003	0.6	0.97	<0.0001	0.89
MD		0.41	0.002	0.5	0.95	<0.0001	0.81
RD		0.63	0.001	0.2	0.95	<0.0001	0.78
RSF		0.27	0.003	1.2	0.86	0.002	0.52
MMPF	CST	0.09	0.001	1.5	0.97	0.0003	0.74
MWF		0.16	0.003	1.7	0.97	<0.0001	0.95
R1		1.04	0.004	0.4	0.98	<0.0001	0.91
MTR		0.41	0.002	0.5	0.78	0.01	0.37
FA		0.47	0.005	1.0	0.95	<0.0001	0.86
MD		0.47	0.005	1.0	0.96	<0.0001	0.85
RD		0.64	0.003	0.5	0.96	<0.0001	0.81
RSF	Arcuate Fasciculus	0.26	0.004	1.7	0.82	0.005	0.72
MMPF		0.10	0.002	2.1	0.92	<0.0001	0.79
MWF		0.16	0.002	1.4	0.98	<0.0001	0.93
R1		1.07	0.001	0.1	0.97	<0.0001	0.90
MTR		0.42	0.003	0.6	0.97	<0.0001	0.92

One-way ANOVAs demonstrated no significant differences between ICC computed for individual time point pairs or between average ICC and individual time point ICC comparisons for the CST (F(9,70) = 0.74, p = .67) and the Fornix (F(9,70) = 0.19, p = .07). Although initially a difference was suggested for the Arcuate Fasciculus (F(9,70) = 2.2, p = .03), no comparisons survived correction for multiple comparisons as shown with Tukey post-hoc correction.