Shimoyama Takashi, Yoshida Ken, Muro Yoshinao, Ito Haruyasu, Matsushita Takayuki, Oto Yohsuke, Ukichi Taro, Noda Kentaro, Kurosaka Daitaro
Division of Rheumatology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
Department of Dermatology, Nagoya University Graduate School of Medicine, Aichi, Japan.
Rheumatology (Oxford). 2024 Oct 1;63(10):2684-2693. doi: 10.1093/rheumatology/keae125.
Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders significantly impacting skeletal muscles; however, the precise correlation between muscle magnetic resonance imaging (MRI) findings, muscle pathology, disease subtypes and clinical characteristics remains uncertain. Thus, we investigated the association of muscle MRI findings in IIMs with muscle pathology and clinical features.
New-onset IIM patients underwent proximal upper and/or lower limb muscle MRI. Patterns of muscle oedema on MRI were categorised into fascial, honeycomb, peripheral, foggy, dense, or coarse dot patterns and compared with inflammatory cell infiltration sites in corresponding muscle biopsies. The incidence of MRI patterns was examined in patient subgroups using myositis-specific antibodies (MSAs) and 2017 EULAR/ACR classification criteria. Univariate and multivariate analyses were conducted to determine the odds ratios (ORs) of MRI findings for clinical characteristics.
Fifty-six of 85 patients underwent muscle biopsy. Foggy, honeycomb and fascial patterns at biopsy sites correlated with inflammatory cell infiltration in the endomysium (OR 11.9, P = 0.005), perimysium (OR 6.0, P = 0.014) and fascia (OR 16.9, P < 0.001), respectively. Honeycomb and foggy patterns were characteristic of patients with anti-TIF1γ or anti-Mi2 antibodies and MSA-negative dermatomyositis, and those with anti-SRP or anti-HMGCR antibodies and MSA-negative polymyositis (PM), respectively. The honeycomb pattern positively correlated with malignancy (OR 6.87, P < 0.001) and Gottron sign (OR 8.05, P = 0.002); the foggy pattern correlated with muscle weakness (OR 11.24, P = 0.005). The dense dot pattern was associated with dysphagia (OR 6.27, P = 0.006) and malignancy (OR 8.49, P = 0.002).
Muscle MRI holds promise in predicting muscle pathology, disease subtypes and clinical manifestations of IIMs.
特发性炎性肌病（IIMs）是显著影响骨骼肌的自身免疫性疾病；然而，肌肉磁共振成像（MRI）表现与肌肉病理学、疾病亚型及临床特征之间的确切相关性仍不明确。因此，我们研究了IIMs患者肌肉MRI表现与肌肉病理学及临床特征之间的关联。
新发IIM患者接受近端上肢和/或下肢肌肉MRI检查。MRI上的肌肉水肿模式分为筋膜型、蜂窝状、外周型、雾状、致密型或粗点状模式，并与相应肌肉活检中的炎性细胞浸润部位进行比较。使用肌炎特异性抗体（MSAs）和2017年欧洲抗风湿病联盟/美国风湿病学会（EULAR/ACR）分类标准，在患者亚组中检查MRI模式的发生率。进行单因素和多因素分析以确定MRI表现与临床特征的比值比（ORs）。
85例患者中有56例接受了肌肉活检。活检部位的雾状、蜂窝状和筋膜型模式分别与肌内膜（OR 11.9，P = 0.005）、肌束膜（OR 6.0，P = 0.014）和筋膜（OR 16.9，P < 0.001）中的炎性细胞浸润相关。蜂窝状和雾状模式分别是抗TIF1γ或抗Mi2抗体阳性且MSA阴性的皮肌炎患者，以及抗SRP或抗HMGCR抗体阳性且MSA阴性的多发性肌炎（PM）患者的特征。蜂窝状模式与恶性肿瘤（OR 6.87，P < 0.001）和Gottron征（OR 8.05，P = 0.002）呈正相关；雾状模式与肌肉无力（OR 11.24，P = 0.005）相关。致密点状模式与吞咽困难（OR 6.27，P = 0.006）和恶性肿瘤（OR 8.49，P = 0.002）相关。
肌肉MRI在预测IIMs的肌肉病理学、疾病亚型和临床表现方面具有前景。
