TABLE 4.
Intra-scanner variability results per brain structure for three different MRI systems.
| Brain structures | CV (%; mean ± SD) | AVD (mL; mean ± SD) | ICC [95% CI] | DSC (mean ± SD) |
| Whole brain | ||||
| Achieva | 0.18 ± 0.14 | 3.11 ± 2.50 | 1.000 [0.999,1.000] | 0.92 ± 0.00 |
| Ingenia | 0.21 ± 0.14 | 3.32 ± 2.17 | 1.000 [0.999,1.000] | 0.98 ± 0.00 |
| GE | 0.29 ± 0.29 | 4.70 ± 4.60 | 0.999 [0.996,1.000] | 0.98 ± 0.00 |
| p-value | 0.418 | 0.453 | 0.144 | |
| Gray matter | ||||
| Achieva | 0.16 ± 0.12 | 1.49 ± 1.13 | 1.000 [0.999,1.000] | 0.93 ± 0.01 |
| Ingenia | 0.52 ± 0.42 | 5.07 ± 4.27 | 0.997 [0.991,0.999] | 0.92 ± 0.01 |
| GE | 0.43 ± 0.42 | 3.82 ± 3.62 | 0.998 [0.995,1.000] | 0.93 ± 0.01 |
| p-value | 0.051 | 0.045 | 0.822 | |
| Cortical gray matter | ||||
| Achieva | 0.29 ± 0.19 | 2.61 ± 1.75 | 0.999 [0.998,1.000] | 0.93 ± 0.01 |
| Ingenia | 0.54 ± 0.38 | 4.96 ± 3.74 | 0.997 [0.992,0.999] | 0.92 ± 0.01 |
| GE | 0.38 ± 0.48 | 3.24 ± 3.82 | 0.998 [0.995,0.999] | 0.93 ± 0.02 |
| p-value | 0.287 | 0.229 | 0.893 | |
| White matter | ||||
| Achieva | 0.46 ± 0.18 | 2.97 ± 1.24 | 0.998 [0.995,0.999] | 0.94 ± 0.01 |
| Ingenia | 1.06 ± 0.80 | 6.64 ± 4.61 | 0.991 [0.971,0.997] | 0.94 ± 0.01 |
| GE | 0.74 ± 0.34 | 5.16 ± 2.29 | 0.994 [0.983,0.998] | 0.94 ± 0.01 |
| p-value | 0.034 | 0.028 | 0.088 | |
| Frontal cortex | ||||
| Achieva | 0.60 ± 0.35 | 1.46 ± 0.77 | 0.998 [0.993,0.999] | 0.90 ± 0.01 |
| Ingenia | 0.63 ± 0.55 | 1.52 ± 1.32 | 0.996 [0.989,0.999] | 0.90 ± 0.02 |
| GE | 0.99 ± 0.57 | 2.36 ± 1.41 | 0.994 [0.982,0.998] | 0.89 ± 0.02 |
| p-value | 0.132 | 0.164 | 0.940 | |
| Parietal cortex | ||||
| Achieva | 1.58 ± 1.19 | 2.44 ± 1.69 | 0.980 [0.936,0.994] | 0.87 ± 0.01 |
| Ingenia | 1.52 ± 1.24 | 2.33 ± 1.71 | 0.981 [0.940,0.994] | 0.87 ± 0.02 |
| GE | 1.78 ± 1.22 | 2.73 ± 2.17 | 0.980 [0.938,0.994] | 0.87 ± 0.03 |
| p-value | 0.829 | 0.850 | 0.464 | |
| Temporal cortex | ||||
| Achieva | 1.94 ± 1.19 | 3.16 ± 1.88 | 0.964 [0.890,0.989] | 0.89 ± 0.02 |
| Ingenia | 1.56 ± 1.30 | 2.61 ± 2.16 | 0.974 [0.921,0.992] | 0.90 ± 0.01 |
| GE | 1.11 ± 0.74 | 1.82 ± 1.15 | 0.990 [0.970,0.997] | 0.90 ± 0.02 |
| p-value | 0.148 | 0.151 | 0.165 | |
| Hippocampus, total | ||||
| Achieva | 1.44 ± 0.87 | 0.14 ± 0.09 | 0.986 [0.957,0.996] | 0.90 ± 0.01∧ |
| Ingenia | 1.63 ± 0.91 | 0.16 ± 0.08 | 0.985 [0.953,0.995] | 0.91 ± 0.01• |
| GE | 0.95 ± 0.67 | 0.09 ± 0.06 | 0.994 [0.981,0.998] | 0.93 ± 0.01∧• |
| p-value | 0.142 | 0.119 | <0.001 | |
| Hippocampus, left | ||||
| Achieva | 2.90 ± 1.87 | 0.14 ± 0.09 | 0.956 [0.865,0.986] | 0.90 ± 0.01∧ |
| Ingenia | 3.14 ± 2.15 | 0.15 ± 0.10 | 0.941 [0.823,0.981] | 0.90 ± 0.02• |
| GE | 1.46 ± 1.14 | 0.07 ± 0.05 | 0.988 [0.963,0.996] | 0.92 ± 0.01∧• |
| p-value | 0.049 | 0.063 | <0.001 | |
| Hippocampus, right | ||||
| Achieva | 1.35 ± 1.45 | 0.06 ± 0.06 | 0.988 [0.963,0.996] | 0.91 ± 0.01∧ |
| Ingenia | 1.11 ± 0.88 | 0.05 ± 0.04 | 0.992 [0.974,0.997] | 0.91 ± 0.01 |
| GE | 1.16 ± 0.71 | 0.06 ± 0.04 | 0.992 [0.973,0.997] | 0.93 ± 0.01∧ |
| p-value | 0.848 | 0.957 | <0.001 | |
| Lateral ventricles | ||||
| Achieva | 0.66 ± 0.84 | 0.28 ± 0.29 | 0.999 [0.998,1.000] | 0.96 ± 0.01 |
| Ingenia | 0.75 ± 1.09 | 0.34 ± 0.46 | 0.999 [0.997,1.000] | 0.96 ± 0.01 |
| GE | 1.13 ± 1.33 | 0.55 ± 0.78 | 0.997 [0.973,0.997] | 0.97 ± 0.01 |
| p-value | 0.407 | 0.475 | 0.054 | |
|
| ||||
| All volumes | Mean CV (%; mean ± SD) | Mean AVD (mL; mean ± SD) | Mean ICC [95% CI] | Mean DSC (mean ± SD) |
|
| ||||
| Achieva | 1.05 ± 0.87 | 1.63 ± 1.29 | 0.988 [0.977,0.998] | 0.91 ± 0.01 |
| Ingenia | 1.15 ± 0.81 | 2.47 ± 2.30 | 0.987 [0.975,0.998] | 0.92 ± 0.01 |
| GE | 0.95 ± 0.46 | 2.24 ± 1.88 | 0.993 [0.989,0.997] | 0.93 ± 0.04 |
Brain volumes used to calculate measurements of precision were computed by the icobrain dm segmentation software. Coefficients of variation (CV, %), AVD (mL), intraclass correlation coefficients (ICC, [95% CI]), and Dice similarity coefficients (DSC, mean ± SD) were reported. The highest CV and lowest ICC and DSC values amongst all structures were highlighted in “bold.” Achieva: Philips Medical Systems Achieva dStream 1.5T. Ingenia: Philips Medical Systems Ingenia 3T. GE: GE Discovery MR750w 3T. p-value < 0.005 for “all scanners” differences were highlighted in “bold.” ∧p-value < 0.005 between Achieva and GE ⋅p-value < 0.005 between Ingenia and GE.