MRI score values in the 90 patients obtaining radiography at followup, 86 of whom had radiographic signs of sacroiliitis; sensitivity, specificity, and accuracy of MRI abnormalities at baseline in relation to the presence of ankylosing spondylitis according to the modified New York criteria9 in 58 patients at followup.
| No. Patients | Sensitivity | Specificity | Accuracy | |
|---|---|---|---|---|
| Total activity score | ||||
| 0 | 12 | 0.05 | 0.72 | 0.29 |
| ≥ 1 | 78 | 0.95 | 0.28 | 0.71 |
| ≥ 2 | 67 | 0.88 | 0.50 | 0.74 |
| ≥ 3 | 56 | 0.83 | 0.75 | 0.80 |
| ≥ 4 | 52 | 0.78 | 0.78 | 0.78 |
| Total chronic score | ||||
| 0 | 13 | 0.02 | 0.63 | 0.23 |
| ≥ 1 | 77 | 0.98 | 0.38 | 0.77 |
| ≥ 2 | 64 | 0.90 | 0.63 | 0.80 |
| ≥ 3 | 60 | 0.86 | 0.69 | 0.80 |
| ≥ 4 | 58 | 0.86 | 0.75 | 0.82 |
| Erosion score | ||||
| 0 | 15 | 0.02 | 0.56 | 0.21 |
| ≥ 1 | 75 | 0.98 | 0.44 | 0.79 |
| ≥ 2 | 59 | 0.88 | 0.75 | 0.83 |
| ≥ 3 | 54 | 0.81 | 0.78 | 0.80 |
| ≥ 4 | 43 | 0.72 | 0.97 | 0.81 |
| Fatty marrow deposition score | ||||
| 0 | 31 | 0.17 | 0.34 | 0.23 |
| ≥ 1 | 59 | 0.83 | 0.66 | 0.77 |
| ≥ 2 | 53 | 0.78 | 0.75 | 0.77 |
| ≥ 3 | 41 | 0.60 | 0.81 | 0.68 |
| ≥ 4 | 37 | 0.57 | 0.88 | 0.68 |