Table 1.

Bland-Altman and correlation analysis of ultrasound and MRI results

	Descriptive statistics	Reproducibility				Inter-observer				Intra-observer
		(scan 1 vs. scan 2)				variability				variability
		Bland-Altman		Correlation		Bland-Altman		Correlation		Bland-Altman		Correlation
	Mean ± SD (range)	d	σd	r	P value	d	σd	r	P value	d	σd	r	P value
Ultrasound
ONSD 3 mm	5.43 ± 0.49	−0.07	±0.69	0.75	0.001	0.25	±0.51	0.82	<0.001	−0.01	±0.22	0.97	<0.001
	(4.6 – 6.4)
ONSD 5 mm	5.53 ± 0.57	−0.11	±0.66	0.82	<0.001	0.52	±1.12	0.62	0.01	−0.09	±0.47	0.90	<0.001
	(4.8 – 6.8)
MR imaging
ONSD 3 mm	5.69 ± 0.77	0.00	±0.85	0.83	<0.001	−0.27	±0.36	0.98	<0.001	−0.01	±0.26	0.99	<0.001
	(4.7 – 7.9)
ONSD 5 mm	5.09 ± 0.66	−0.01	±0.87	0.76	0.001	−0.14	±0.39	0.97	<0.001	0.01	±0.25	0.98	<0.001
	(4.2 – 7.1)

d, mean difference; σd, limits of agreement; r, correlation coefficient.