Table 2.

Accuracy of linear phantom measurements.

Phantom Position	Measurement category	Mean difference (True value − MRI)	95% limits of agreement (True value − MRI)	p-value
1	3D distances (mm)	0.01	−0.41, 0.42	<0.001
	2D distances sagittal (mm)	−0.06	−0.59, 0.48	<0.001
	2D distances frontal (mm)	−0.01	−0.49, 0.47	<0.001
	2D distances horizontal (mm)	0.11	−0.37, 0.59	<0.001
2	3D distances (mm)	0.08	−0.33, 0.49	<0.001
	2D distances sagittal (mm)	−0.06	−0.48, 0.36	<0.001
	2D distances frontal (mm)	0.03	−0.40, 0.46	<0.001
	2D distances horizontal (mm)	0.24	−0.13, 0.61	<0.001
3	3D distances (mm)	−0.12	−0.50, 0.26	<0.001
	2D distances sagittal (mm)	0.00	−0.40, 0.41	<0.001
	2D distances frontal (mm)	−0.22	−0.46, 0.02	<0.001
	2D distances horizontal (mm)	−0.02	−0.48, 0.43	<0.001

All given values refer to 24 different distances per measurement category. p-values < 0.05 indicate equivalence between true values and MRI measurements (two one-sided tests with an equivalence margin of ±0.5 mm).