Berlin MRI scores applied in this study21 24
| Grade 0 | Grade 1 | Grade 2 | Grade 3 | |
|---|---|---|---|---|
| Sacroiliac joints | ||||
| Active inflammation (BMO of quadrant area) | Absent | Up to 33% of the quadrant area | 33–66% | >66% |
| Erosions (per quadrant) | Absent | Minor (one to two erosions) | Moderate (three to five single erosions) | Multiple (confluent erosions) |
| Fatty bone marrow deposition (FMD) per quadrant | Absent | Present | – | – |
| Sclerosis (per joint) | Absent | Present | – | – |
| Ankylosis (per joint) | Absent | Present | – | – |
| Spine | ||||
| Active Inflammation (BMO of VU area) | Absent | <25% of VU area | 25–50% | >50% |
| Erosions (% of the bone surface per VU) | Absent | Minor (one to two erosions) | Moderate (three to five single erosions) | Multiple (confluent erosions) |
| Fatty bone marrow deposition (FMD) per VU | Absent | <25% | 25–50% | >50% |
| Bone proliferation (per VU) | Absent | Syndesmophytes without bridging | Bridging syndesmophytes | Transdiscal ankylosis |
| Active inflammation of the posterior segments (per VU) | Absent | Minor inflammation | Severe inflammation | – |
| Non-axial locations | ||||
| Enthesitis/osteitis (per location)* | Absent | Minor | Moderate to severe | |
| Synovitis/effusion (per joint)* | Absence of joint effusion | Slightly increased fluid collection | Moderate to severe fluid collection | |
| Erosions (per joint)* | Absent | Suspicion of erosion | Definite evidence of erosion | |
*See text for list of entheseal locations and scored joints.
BMO, bone marrow oedema; VU, vertebral unit.