The definitions and scaling of features included in the prelimunary OMERACT Hand Osteoarthritis Magnetic Resonance Imaging Score.
| Definition | Scaling | |
|---|---|---|
| Synovitis | Thickened synovium with enhancement of gadolinium | 0 = normal; 1 = mild; 2 = moderate; 3 = severe. The 1–3 scores are defined by thirds of the presumed maximum volume of enhancing tissue in the synovial compartment |
| Erosive damage | Subchondral bone loss, including erosions (sharply marginated bone lesion with cortical break in at least one plane), bone attrition (flattening or depression of the joint plate) and bone resorption | 0 = normal; 1 = mild, ≤ 10% of bone volume or ≤ 25% joint surface affected*, 2 moderate, 11–20% of bone volume and/or 26–50% of joint surface affected*, 3 = severe, > 20% of bone volume and/or > 50% of joint surface affected* |
| Cyst | A sharply marginated bone lesion with typical signal characteristics* without a cortical break. * Increased signal intensity on T1w fs, T2w fs or STIR images | 0 = normal; 1 = mild, ≤ 10% of bone volume*; 2 = moderate, 11–20% of bone volume*; 3 = severe, > 20% of bone volume* |
| Osteophyte | Abnormal bone protuberance at joint margins or surfaces | 0 = normal, no osteophytes; 1 = mild, 1–3 small osteophytes; 2 = moderate, ≥ 4 small osteophytes and/or ≥ 1 moderate osteophyte(s); 3 = severe, at least 1 large osteophyte |
| Cartilage space loss | Loss of the cartilage space based on the inter-bone distance | 0 = normal; 1 = mild, loss of cartilage space without bone-to-bone contract; 2 = moderate, focal complete loss of cartilage space; 3 = severe, complete cartilage space loss affecting > 50% of the articulating joint area |
| Malalignment | Angulation or subluxation of joints in the frontal plane | 0 = no apparent malalignment; 1 = mild, ≤ 10° angulation and/or not congruent joint surfaces; 2 = moderate: 11–20° angulation and/or or moderate subluxation without crossing the midline; 3 = severe: > 20° angulation and/or subluxation with crossing the midline |
| Bone marrow lesions | A lesion within the trabecular bone with signal characteristic consistent with increased water content* and with ill-defined margins. * High signal intensity on STIR or T2w fs images | 0 = normal; 1 = mild, 1–33% of bone volume*; 2 = moderate, 34–66% of bone volume*; 3 = severe, 67–100% of bone volume* |
↵* Bone volume and joint surface refer to the proximal and distal part of the joint combined. The assessed bone volume should extend from the articular surface to a depth of 0.5 cm for distal interphalangeal joints and 1.0 cm for proximal interphalangeal joints on either side;
# 0.5 increments for the assessment of synovitis, erosions, and bone marrow lesions. T1w: T1-weighted, T2w: T2-weighted, fs: fat-suppressed, STIR: short-tau inversion recovery.