Mylène Jansen

244 Chapter 12 Table 1 : Patient characteristics and image analysis (most affected compartment) results Patient characteristics All patients (n=14) Baseline Age (years) 53.9 (7.7) Weight (kg) 87.6 (13.7) BMI (kg/m 2 ) 27.6 (3.9) Male sex, n (%) 9 (64) Image analysis results Baseline 2 years Δ2-year X-ray JSW (mm) 1.7 (1.9) 2.7 (1.6) 1.1 (1.3) MRI cartilage thickness (mm) 2.0 (0.9) 2.2 (0.9) 0.2 (0.3) 3D CT JSW (mm) 4.4 (1.0) 4.6 (0.8) 0.2 (0.8) 2D CT JSW (mm) 4.2 (1.5) 4.2 (1.5) 0.0 (1.6) Mean and standard deviation or n (%) are given. BMI: body mass index;; JSW: joint space width. Correlations The cross-sectional correlations between all 4 techniques, of the baseline and 2-year values combined, are shown in Figure 3. The scatterplot matrix (left panel) shows that correlations were present between all techniques, as confirmed by the Pearson R and p- values (right panel). All correlations were statistically significant (all p< 0.023) and most were moderate or strong, with 2D CT and 3D CT showing a very strong correlation. Figure 3 : Cross-sectional correlations of combined baseline and 2-year values for all 4 techniques, displayed (A) visually as a scatterplot matrix and (B) with Pearson R and p- values. The dotted line in (A) indicates the origin (0). Bold p- values indicate statistical significance ( p< 0.05). The correlations between the 2-year changes of all 4 techniques are shown in Figure 4. It can be seen in the scatterplot matrix that between most techniques, a clear correlation was absent. This was confirmed by the Pearson R and p- values.