Table 2:

Intraobserver reliability and precision of hippocampal FA and MD values (n = 20)

	Mean ± SD	Diff ± SD	t value	r	r_s	ICC	SEM	CI 95%	CV	R95 (%)
FA left	246 ± 26	2 ± 12	0.94	.90	.88	.95	8.4	±16	3.5%	23 (9.4%)
FA right	229 ± 20	−1 ± 9	−0.38	.91	.89	.95	6.0	±12	2.7%	17 (7.3%)
FA mean	237 ± 17	1 ± 8	0.51	.91	.88	.95	5.3	±10	2.2%	15 (6.2%)
MD left	782 ± 40	−1 ± 20	0.08	.91	.94	.94	13.8	±27	1.8%	38 (4.9%)
MD right	769 ± 25	0 ± 16	0.08	.82	.81	.90	10.9	±21	1.4%	30 (3.9%)
MD mean	775 ± 28	0 ± 14	0.10	.88	.85	.93	9.9	±19	1.3%	27 (3.5%)

Note.— FA indicates fractional anisotropy (×10³); MD, mean diffusivity (μm²/s); Mean, pooled mean (1st and 2nd assessment of one observer) ± pooled SD; Diff, difference of 1st–2nd assessment ± SD of difference; t value, corresponding to paired t test, all P values >0.20; r, Pearson correlation coefficient; r_s, Spearman rank correlation coefficient; ICC, intraclass correlation coefficient; SEM, standard error of measurement based on within-subject variance; CI 95%, 95% confidence interval (±1.96 × SEM); CV = √(mean of within subject variance/mean squared); R95, repeatability according to Bland and Altman20; R95 = √2 × 1.96 × SEM; %, percentage of mean = R95/mean × 100.