In vitro evaluation of cerebrospinal fluid velocity measurement in type I Chiari malformation: repeatability, reproducibility, and agreement using 2D phase contrast and 4D flow MRI

Table 5 Effect sizes and corresponding p values estimated from the linear mixed-effects model for velocity measurements

Effect	Effect size (95% CI) [cm/s]	p value
Intercept (Center 1: 2D PC MRI at FM)	14.16 (13.12, 15.21)	4.4 × 10^–74*
Scan type (4D – 2D)	−0.02 (−0.28, 0.24)	0.86
Center 2	−0.45 (−1.27, 0.36)	0.27
Center 3	−1.17 (−2.63, 0.29)	0.12
Center 4	−2.09 (−3.42, 0.76)	2.2 × 10^–3*
Center 5	−2.52 (−3.23, −1.76)	3.2 × 10^–10*
C1	−0.80 (−1.37, −0.23)	0.006
C2M	−0.49 (−0.96, −0.02)	0.042
C2B	0.01 (−0.46, 0.48)	0.95
C3	−1.21 (−1.67, −0.75)	6.22 × 10^–7*
C4	−1.36 (−1.85, −0.87)	1.08 × 10^–7*
C5	−0.54 (−1.15, 0.07)	0.084
C6	−1.26 (−1.77, −0.75)	2.0 × 10^–6*
C7	−1.71 (−2.17, −1.24)	9.5 × 10^–12*

The mean effect size is provided, along with the 95% confidence interval (CI). We used Bonferroni correction to account for multiple testing. * represents statistical significance under Bonferroni correction where p < 0.05/14 = 0.0036

ISSN: 2045-8118