Table 2.
MRI features in different stages of disease activity in 47 children with juvenile idiopathic arthritis (JIA)a
| Features | Group 1 (active JIA) 58 knees | Group 2 (inactive JIA) 36 knees |
|---|---|---|
| Synovial hypertrophy | 21 (36.2) | 7 (19.4) |
| Cartilage lesions | 9 (15.5) | 3 (8.3) |
| Bone erosions | 4 (6.9) | 2 (5.6) |
| Bone marrow changes | 24 (41.4) | 16 (44.4) |
| Infrapatellar fat pad heterogeneity | ||
| - Absent | 27 (46.6) | 5 (13.9) * |
| - Minimal | 25 (43.1) | 27 (75.0) |
| - Marked | 6 (10.3) | 4 (11.1) |
| Water | 25 (80.6) | 16 (51.6) |
| Scar tissue | 9 (29.0) | 18 (58.1) ** |
| Effusion | 54 (93.1) | 36 (100.0) |
| Suprapatellar bursa | ||
| - Absent | 16 (27.6) | 10 (27.8) |
| - Minimal | 33 (56.9) | 21 (58.3) |
| - Marked | 9 (15.5) | 5 (13.9) |
| Lateral recesses | ||
| - Absent | 29 (50.0) | 28 (77.8) |
| - Minimal | 21 (36.2) | 8 (22.2) |
| - Marked | 8 (13.8) | - |
| Popliteal cyst | ||
| - Absent | 43 (74.1) | 33 (91.7) |
| - Minimal | 14 (24.1) | 3 (8.3) |
| - Marked | 1 (1.7) | - |
| Central recesses | ||
| - Absent | 24 (41.4) | 9 (25.0) |
| - Minimal | 29 (50.0) | 22 (61.1) |
| - Marked | 5 (8.6) | 5 (13.9) |
| Tendinopathy/internal derangement | 3 (5.2) | - |
| Popliteal lymph nodes | ||
| - 0 | 13 (22.4) | 11 (30.6) |
| - 1 | 16 (27.6) | 9 (25.0) |
| - ≥2 | 29 (50.0) | 16 (44.4) |
*P < 0.010 , **P < 0.005
aValues are number of knees (% of all)