Department of Medicine, University of Alberta, Edmonton, Alberta, Canada Department of Rheumatology, Balgrist University Hospital, Zurich, Switzerland.
Copenhagen Center for Arthritis Research, Center for Rheumatology and Spinal Diseases, University of Copenhagen, Copenhagen, Denmark.
Ann Rheum Dis. 2015 Nov;74(11):1976-82. doi: 10.1136/annrheumdis-2014-205408. Epub 2014 Jun 12.
To determine candidate lesion-based criteria for a positive sacroiliac joint (SIJ) MRI based on bone marrow oedema (BMO) and/or erosion in non-radiographic axial spondyloarthritis (nr-axSpA); to compare the performance of lesion-based criteria with global evaluation by expert readers.
Two independent cohorts A/B of 69/88 consecutive patients with back pain aged ≤50 years, with median symptom duration 1.3/10.0 years, were referred for suspected SpA (A) or acute anterior uveitis plus back pain (B). Patients were classified according to rheumatologist expert opinion based on clinical examination, pelvic radiography and laboratory values as having nr-axSpA (n=51), ankylosing spondylitis (n=34) or non-specific back pain (n=72). Four blinded readers assessed SIJ MRI, recording the presence/absence of SpA by concomitant global evaluation of T1-weighted spin echo (T1SE) and short τ inversion recovery (STIR) scans and, thereafter, whether BMO and/or erosion were present/absent in each SIJ quadrant of each MRI slice. We derived candidate lesion-based criteria based on the number of SIJ quadrants with BMO and/or erosion and calculated mean sensitivity and specificity for SpA.
For both cohorts A/B, global assessment showed high specificity (0.95/0.83) compared with the Assessment in SpondyloArthritis international Society (ASAS) definition (0.76/0.74). BMO ≥3 (0.89/0.84) or ≥4 (0.92/0.87) showed comparably high specificity to global assessment. Erosion ≥2 and/or BMO ≥3 or ≥4 were associated with comparably high sensitivity to global assessment without affecting specificity. These combined criteria showed both higher sensitivity and specificity than the ASAS definition.
Lesion-based criteria for a positive SIJ MRI based on both BMO and/or erosion performed best for classification of axial SpA, reflecting the contextual information provided by T1SE and STIR sequences.
基于骨髓水肿（BMO）和/或侵蚀，确定非放射性轴性脊柱关节炎（nr-axSpA）中阳性骶髂关节（SIJ）MRI 的候选病变标准；比较病变标准与专家读者的整体评估的表现。
对 2 个独立队列 A/B（69/88 例年龄≤50 岁的背痛连续患者，中位症状持续时间为 1.3/10.0 年）进行了研究，这些患者因疑似 SpA（A）或急性前葡萄膜炎合并背痛（B）而就诊。根据临床检查、骨盆 X 线和实验室值，由风湿病专家意见将患者分为 nr-axSpA（n=51）、强直性脊柱炎（n=34）或非特异性背痛（n=72）。4 位盲法读者评估了 SIJ MRI，通过同时评估 T1 加权自旋回波（T1SE）和短 τ反转恢复（STIR）扫描的整体评估记录 SIJ 的存在/不存在 SpA，此后，记录每个 MRI 切片的每个 SIJ 象限中是否存在 BMO 和/或侵蚀。我们根据 BMO 和/或侵蚀的 SIJ 象限数量得出候选病变标准，并计算 SpA 的平均敏感性和特异性。
对于队列 A/B，整体评估显示出较高的特异性（0.95/0.83），与评估强直性脊柱炎国际协会（ASAS）的定义（0.76/0.74）相比。BMO≥3（0.89/0.84）或≥4（0.92/0.87）显示出与整体评估相当高的特异性。侵蚀≥2 以及/或 BMO≥3 或≥4 与整体评估具有相当高的敏感性而不影响特异性。这些综合标准比 ASAS 定义具有更高的敏感性和特异性。
基于 BMO 和/或侵蚀的阳性 SIJ MRI 的病变标准对于轴性 SpA 的分类效果最佳，反映了 T1SE 和 STIR 序列提供的上下文信息。
