Patient-level sum scores and inter-reader reliability of the four lesion types in the CANDEN MRI spine scoring system
| Variable | Baseline | Week 52 | Change | |||||||
| Score | Single-measure ICC | Average-measure ICC | Score | Single-measure ICC | Average-measure ICC | Score | Single-measure ICC | Average-measure ICC | Wilcoxon test, p value | |
| CANDEN MRI spine inflammation score, range 0–614 | 13.2 (5; 0–132) | 0.91 (0.88–0.92) | 0.95 (0.94–0.96) | 2.4 (1; 0–19) | 0.77 (0.67–0.86) | 0.87 (0.81–0.92) | −10.8 (−3; −113 to 1) | 0.88 (0.86–0.92) | 0.94 (0.93–0.96) | <0.001 |
| Vertebral body corner inflammation subscore, range 0–254 | 8.0 (3; 0–89) | 0.93 (0.91–0.95) | 0.97 (0.95–0.97) | 1.6 (0; 0–14) | 0.84 (0.70–0.87) | 0.91 (0.82–0.93) | −6.4 (−2; −75 to 1) | 0.90 (0.87–0.94) | 0.95 (0.93–0.97) | <0.001 |
| Spondylodiscitis subscore, range 0–162 | 1.8 (0; 0–25) | 0.84 (0.74–0.91) | 0.91 (0.85–0.95) | 0.4 (0; 0–9) | 0.66 (0.58–0.69) | 0.80 (0.74–0.82) | −1.3 (0; −22 to 0) | 0.82 (0.79–0.89) | 0.90 (0.88–0.94) | 0.003 |
| Facet joint inflammation subscore, range 0–46 | 1.0 (0; 0–13) | 0.78 (0.73–0.80) | 0.88 (0.84–0.96) | 0.2 (0; 0–2) | 0.50 (0.23–0.64) | 0.66 (0.37–0.78) | −0.8 (0; −13 to 2) | 0.79 (0.75–0.89) | 0.88 (0.85–0.94) | 0.001 |
| Posterolateral elements inflammation subscore, range 0–152 | 2.4 (0; 0–19) | 0.55 (0.45–0.71) | 0.71 (0.62–0.83) | 0.2 (0; 0–2) | 0.21 (0.16–0.32) | 0.34 (0.28–0.48) | −2.2 (0; −18 to 1) | 0.55 (0.44–0.70) | 0.71 (0.61–0.83) | <0.001 |
| CANDEN MRI spine fat score, range 0–510 | 6.8 (2; 0–49) | 0.79 (0.75–0.86) | 0.89 (0.86–0.92) | 8.3 (4; 0–57) | 0.79 (0.71–0.85) | 0.88 (0.83–0.92) | 1.5 (0; −4 to 11) | 0.59 (0.46–0.73) | 0.74 (0.63–0.85) | <0.001 |
| CANDEN MRI spine bone erosion score, range 0–208 | 0.3 (0; 0–2) | 0.38 (0.32–0.52) | 0.55 (0.48–0.68) | 0.2 (0; 0–2) | 0.32 (0.22–0.58) | 0.49 (0.36–0.73) | −0.1 (0; −1 to 0) | 0.01 (−0.08 to 0.29) | 0.01 (−0.17 to 0.45) | 0.444 |
| CANDEN MRI spine new bone formation score, range 0–460 | 3.1 (1; 0–24) | 0.39 (0.27–0.49) | 0.56 (0.42–0.65) | 3.4 (1; 0–27) | 0.38 (0.23–0.56) | 0.55 (0.38–0.71) | 0.2 (0; −1 to 3) | 0.00 (0.00–0.00) | 0.00 (0.00–0.00) | 0.047 |
Scores are reported as mean (median; range) using the average score of all readers. ICCs are reported as the median (IQR) of 21 pairwise combinations of readers. Wilcoxon test for change between baseline and week 52.
CANDEN, Canada-Denmark; ICC, intraclass correlation coefficient.