Adams E M, Chow C K, Premkumar A, Plotz P H
Arthritis and Rheumatism Branch, National Institute of Arthritis and Metabolic and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Radiographics. 1995 May;15(3):563-74. doi: 10.1148/radiographics.15.3.7624563.
Magnetic resonance (MR) imaging is useful for demonstrating the soft-tissue and musculature changes seen in patients with idiopathic inflammatory myopathies (IIMs). These changes include edema within and around muscle, subcutaneous reticulation, muscle calcification, and fatty infiltration of muscle. Muscle edema is visible as areas of hyperintensity on short inversion time inversion recovery (STIR) images. Abnormal reticulation of the subcutaneous tissue can be due to subcutaneous edema or an infiltrating process; edema from inflammation appears as areas of low signal intensity on T1-weighted images and as areas of high signal intensity on STIR images. Intramuscular calcium deposition appears as hypointense areas with all pulse sequences. On T1-weighted images, fatty infiltration appears as areas of high signal intensity within muscles. Because of the improved visualization of muscle inflammation provided by STIR imaging and because MR imaging is noninvasive, it has become a useful modality for evaluating patients with IIMs.
磁共振（MR）成像有助于显示特发性炎性肌病（IIM）患者的软组织和肌肉组织变化。这些变化包括肌肉内及周围的水肿、皮下网状改变、肌肉钙化和肌肉脂肪浸润。肌肉水肿在短反转时间反转恢复（STIR）图像上表现为高信号区域。皮下组织的异常网状改变可能是由于皮下水肿或浸润性病变；炎症引起的水肿在T1加权图像上表现为低信号区域，在STIR图像上表现为高信号区域。肌肉内钙沉积在所有脉冲序列上均表现为低信号区域。在T1加权图像上，脂肪浸润表现为肌肉内的高信号区域。由于STIR成像能更好地显示肌肉炎症，且MR成像为非侵入性检查，因此它已成为评估IIM患者的一种有用方法。
