Mylène Jansen

Comparing radiographic JSW and MRI cartilage thickness using CT 245 12 Figure 4 : Correlations of 2-year changes over time for all 4 techniques, displayed (A) visually as a scatterplot matrix and (B) with Pearson R and p- values. The dotted line indicates the origin (0). Bold p- values indicate statistical significance ( p< 0.05). The change in radiographic (plain x-ray) mean JSWwas not statistically significantly correlated with any of the other techniques, including the change in 2D CT JSW ( Δ 2D CT; correlation R= -0.321 and p= 0.262) and the change in MRI cartilage thickness ( Δ MRI; correlation R= 0.484 and p= 0.080). There was a statistically significant, strong correlation between the change in 3D CT median JSW ( Δ 3D CT) and Δ 2D CT mean JSW ( R= 0.651; p= 0.012) and between Δ 3D CT JSW and Δ MRI cartilage mean thickness ( R= 0.619; p= 0.018). None of the other correlations were statistically significant. In Figure 5 these Pearson R and p- values have been added to the triangle of imaging techniques as depicted in Figure 1. Figure 5 : The 3 different imaging methods used for (in)direct cartilage quantification. The key characteristics are listed underneath each modality, and key differences between modalities are displayed in gray. For CT, both 3D and 2D joint space width measurements were used, for comparison with MRI and radiography respectively. Correlations (Pearson R and p- values) of the 2-year changes are shown between the techniques.