Definitions of positive MRI-SIJ and X-SIJ for structural lesions in local and central readings
| Definitions of positive MRI-SIJ | |||
|---|---|---|---|
| Patient level | Definitions of positive X-SIJ | ||
| Local reading | Local reading | ||
| Definition 1 | At least unilateral grade ≥1 | Definition 1 | At least unilateral ‘DESIR grade’ 2 |
| Definition 2 | At least unilateral grade 2 | Definition 2 | At least bilateral ‘DESIR grade’ 2 or unilateral ‘DESIR grade’ 3 |
| Definition 3 | Bilateral grade 2 | Definition 3 | Bilateral ‘DESIR grade’ 3 |
| Central reading | Central reading | ||
| Definition 1 | Presence of ≥1 erosion or fatty lesion or ankylosis (partial or total) | Radiographic sacroiliitis | Bilateral ‘mNY grade ≥2’ or at least unilateral ‘mNY grade≥3’ |
| Definition 2 | ≥1 erosion | ||
| Definition 3 | ≥2 erosions | ||
| Definition 4 | ≥3 erosions | ||
| Definition 5 | ≥1 fatty lesion | ||
| Definition 6 | ≥2 fatty lesions | ||
| Definition 7 | ≥3 fatty lesions | ||
| Definition 8 | Presence of ankylosis (partial or total) | ||
| Definition 9 | ≥3 erosions and/or fatty lesions | ||
mNY, modified New York criteria.24 MRI-SIJ, MRI of the sacroiliac joints.