Radiology Unit, Azienda USL-IRCCS di Reggio Emilia; Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena.
Rheumatology Unit, Azienda USL-IRCCS di Reggio Emilia; Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Modena.
Reumatismo. 2024 Sep 11;76(3). doi: 10.4081/reumatismo.2024.1768.
To review the role of sacro-iliac magnetic resonance imaging (MRI) in the diagnosis of axial spondyloarthritis (AxSpA), with a focus on gender differences.
The experience of the authors and the results of an informal literature review are reported.
Inflammatory changes of the sacro-iliac joint are the hallmark of AxSpA. Early, non-radiographic sacroiliitis may be diagnosed with MRI through the assessment of bone marrow edema (BMO) as well as concomitant structural damage. The MRI protocol should include three necessary sequences, i.e., fat-saturated T2-weighted sequences on two orthogonal planes, T1-weighted semi-coronal sequence, and fat-suppressed T1-weighted semi-coronal sequence. Inflammatory changes comprise required signs (BMO and/or osteitis) and additional signs, including synovitis (better defined as joint space enhancement), enthesitis, and capsulitis. Structural changes consist of erosions, sclerosis, fat metaplasia, and ankylosis. Due to mechanical axial strain, inflammatory changes in the sacro-iliac joint can be found in healthy individuals, runners, and patients with nonspecific low back pain. The prevalence of BMO is higher in women during pregnancy and postpartum, even 12 months after childbirth, but the extent and distribution of MRI findings may help in the differential diagnosis. Other challenges in the MRI diagnosis of sacroiliitis are subchondral T2 hyperintensity during developmental age, periarticular sclerosis in healthy subjects, or osteitis condensans ilii, and several pathological conditions that may mimic AxSpA, some of which are more frequently found in women.
The described diagnostic challenges impose a multidisciplinary approach combining imaging findings with clinical and laboratory data.
综述骶髂磁共振成像（MRI）在诊断中轴型脊柱关节炎（AxSpA）中的作用，重点关注性别差异。
报告作者的经验和非正式文献复习的结果。
骶髂关节的炎症改变是 AxSpA 的标志。通过评估骨髓水肿（BMO）以及同时存在的结构损伤，早期非放射性骶髂关节炎可通过 MRI 诊断。MRI 方案应包括三个必要的序列，即两个正交平面的脂肪饱和 T2 加权序列、T1 加权半冠状序列和脂肪抑制 T1 加权半冠状序列。炎症改变包括必需的征象（BMO 和/或骨炎）和附加征象，包括滑膜炎（更好地定义为关节间隙增强）、附着点炎和囊带炎。结构改变包括侵蚀、硬化、脂肪化生和强直。由于机械性轴向应变，健康个体、跑步者和非特异性腰痛患者的骶髂关节炎症改变也可发生。在妊娠和产后期间，女性的 BMO 患病率更高，甚至在产后 12 个月后仍如此，但 MRI 发现的程度和分布可能有助于鉴别诊断。骶髂关节炎 MRI 诊断中的其他挑战是发育年龄时的软骨下 T2 高信号、健康受试者的关节周围硬化或骺炎、以及几种可能模仿 AxSpA 的病理情况，其中一些在女性中更为常见。
所描述的诊断挑战需要采用多学科方法，将影像学表现与临床和实验室数据相结合。
