Nishikai M, Akiya K
Department of Internal Medicine, National Tokyo Medical Center, Meguro-ku, Tokyo.
Ryumachi. 2000 Dec;40(6):881-90.
The purpose of this study was to evaluate the clinical significance of magnetic resonance imaging (MRI) of skeletal muscles in Japanese patients with idiopathic inflammatory myopathies (IIM). MRI was performed in 23 adult patients with IIM, including 10 with polymyositis, 12 with dermatomyositis, and 1 with focal myositis. Seven (73%) of 11 patients with active IIM and 2 (17%) of 12 patients with inactive IIM showed hyperintensity of T 2-weighted images and normal intensity of T 1-weighted images, indicating "edema-like abnormalities" (MRI findings for active myositis). Muscle lipomatosis and fibrosis were demonstrated in four patients and 1 patient, respectively. Considerable selectivity of muscles in developing inflammatory disorders was found. In quadriceps muscles, for example, vastus muscles seemed to be more often affected in DM patients, whereas adductors were more often affected in PM patients. Serial examination of muscle MRIs was carried out in 4 patients and the findings paralleled the disease activities. The muscle MRI findings did not necessarily correlate with other findings, such as the presence of muscle weakness, elevated serum creatine kinase levels, myogenic electromyogram, or muscle biopsy findings. The muscle MRI was considered to be an additional useful tool for the diagnosis, evaluation of disease activity, and planning treatment of IIM.
本研究旨在评估磁共振成像（MRI）对日本特发性炎性肌病（IIM）患者骨骼肌的临床意义。对23例成年IIM患者进行了MRI检查，其中包括10例多发性肌炎患者、12例皮肌炎患者和1例局灶性肌炎患者。11例活动期IIM患者中有7例（73%），12例非活动期IIM患者中有2例（17%）T2加权图像呈高信号，T1加权图像呈正常信号，提示“水肿样异常”（活动期肌炎的MRI表现）。分别在4例和1例患者中发现了肌肉脂肪瘤和纤维化。发现炎症性疾病在肌肉受累方面具有相当的选择性。例如，在股四头肌中，股外侧肌在皮肌炎患者中似乎更常受累，而内收肌在多发性肌炎患者中更常受累。对4例患者进行了肌肉MRI的系列检查，结果与疾病活动情况相符。肌肉MRI表现不一定与其他表现相关，如肌肉无力、血清肌酸激酶水平升高、肌源性肌电图或肌肉活检结果。肌肉MRI被认为是IIM诊断、疾病活动评估和治疗方案制定的一种额外有用工具。
