Marieke van Rosmalen

Diagnostic value of quantitative assessment of brachial plexus MRI in chronic inflammatory neuropathies 63 4 Table 4.4 Mean nerve root sizes per measurement site Nerve root Inflammatory neuropathy (n = 81) Control (n = 42) MD (95% CI) Level of significance CORONAL C5 Ganglion 3.0 (0.8) 2.5 (0.6) 0.5 (0.3 – 0.7) < 0.001 1 cm 2.8 (0.9) 2.2 (0.5) 0.6 (0.3 – 0.8) < 0.001 C6 Ganglion 3.8 (0.9) 3.3 (0.6) 0.5 (0.2 – 0.8) < 0.001 1 cm 3.6 (1.1) 2.9 (0.7) 0.7 (0.3 – 1.1) < 0.001 C7 Ganglion 4.0 (0.9) 3.4 (0.7) 0.7 (0.3 – 1.0) < 0.001 1 cm 3.7 (1.1) 2.8 (0.6) 0.9 (0.4 – 1.4) < 0.001 SAGITTAL C5 Ganglion 21.6 (6.8) 18.5 (5.7) 3.1 (0.7 – 5.6) 0.013 1 cm 20.3 (7.2) 16.7 (4.4) 3.6 (1.1 – 6.1) 0.005 C6 Ganglion 27.2 (9.1) 23.4 (5.2) 3.8 (0.8 – 6.8) 0.013 1 cm 25.3 (11.5) 19.2 (6.5) 6.1 (2.0 – 10.2) 0.004 C7 Ganglion 26.4 (10.4) 22.0 (5.4) 4.4 (1.5 – 7.2) 0.003 1 cm 23.1 (14.7) 16.1 (4.3) 7.1 (0.9 – 13.3) 0.026 Nerve root sizes are mean (standard deviation). Coronal measurements are in millimetres (mm). Sagittal measurements are square millimetres (mm 2 ) Abbreviations: MD = mean difference; CI = confidence interval; SD = standard deviation. ROC analysis and development of risk chart Sagittal measurements were less often successful because of lower data quality and overall lower reliability ( Table 4.2 and 4.3 ). We therefore decided to exclude the measurements in the sagittal plane from further analysis. Results from the ROC analysis are shown in Figure 4.2 . We found a comparable AUC for both predetermined anatomical sites in the coronal plane (G 0 and G 1 ). We developed a risk chart ( Figure 4.3 ) that predicts the absolute chance of having a chronic inflammatory neuropathy, based on different combinations of nerve root sizes of C5, C6 and C7.