Intra- and interreader agreement.
| Interreader | ||||
| PEA, % | κ | ICC | ||
| WBMRI peripheral | Synovitis | 90 | 0.58 | 0.87 |
| Joint BME | 97 | 0.52 | 0.45 | |
| Entheseal STI | 92 | 0.67 | 0.85 | |
| Entheseal BME | 97 | 0.08 | 0.14 | |
| Total inflammationa | 94 | 0.58 | 0.86 | |
| WBMRI axial | BME | 100 | 0.93 | 0.99 |
| Fat | 99 | 0.91 | 0.99 | |
| Erosion | 100 | 1.00 | 1.00 | |
| New bone formation | 100 | 1.00 | 1.00 | |
| Conv. MRI | Synovitis | 85 | 0.87 | 0.96 |
| Tenosynovitis | 85 | 0.75 | 0.92 | |
| BME | 97 | 0.95 | 0.99 | |
| Erosion | 99 | 0.83 | 0.79 | |
| Inflammation | 91 | 0.90 | 0.99 | |
| Intrareader | ||||
| PEA, % | κ | ICC | ||
| WBMRI peripheral | Synovitis | 84 | 0.41 | 0.85 |
| Joint BME | 97 | 0.72 | 0.91 | |
| Entheseal STI | 93 | 0.41 | 0.74 | |
| Entheseal BME | 97 | 0.34 | 0.35 | |
| Total inflammationa | 92 | 0.50 | 0.93 | |
| WBMRI axial | BME | 100 | 0.93 | 0.67 |
| Fat | 99 | 0.82 | 0.97 | |
| Erosion | 100 | 0.83 | 0.91 | |
| New bone formation | 98 | 0.17 | 0.23 | |
| Conv. MRI | Synovitis | 76 | 0.83 | 0.93 |
| Tenosynovitis | 89 | 0.68 | 0.87 | |
| BME | 94 | 0.88 | 0.99 | |
| Erosion | 93 | 0.19 | 0.20 | |
| Inflammation | 89 | 0.84 | 0.99 | |
Values are for 10 participants (psoriatic arthritis, n = 4; rheumatoid arthritis, n = 3; healthy controls, n = 3), and for all anatomical areas considered together.
↵aTotal inflammatory activity (i.e., the sum of joint and entheseal soft tissue and bone inflammation). BME: bone marrow edema; Conv. MRI: conventional MRI; ICC: 2-way random effects intraclass correlation coefficient, single measure absolute agreement; Kappa: Cohen’s Kappa, quadratic weighted; MRI: magnetic resonance imaging; PEA: percentage exact agreement; STI: soft tissue inflammation; WBMRI: whole-body MRI.